Overview of reaction types organic reaction database

Reaction name	Description	namespace	Count
1,2-dihaloalkene reduction	Conversion of a 1,2-dihaloalkene to a monosubstituted haloalkene.	i	105	Go
2H-chromene synthesis from terminal alkyne	Aromatic substitution reaction and intramolecular ring-closing reaction of a phenyl propargyl ether to form a 2H-chromene.	i	28	Go
Acetylation	Adding a (protective) acetyl group to a hydroxyl group. Source: Wikipedia	i	699	Go
Acid alkylation with diazo compounds	With diazo compounds acids react to esters, with diazomethane the reaction product is a methyl ester. (March 0-28)	i	396	Go
Activation reaction	Any reaction that activates amines and alcohols for subsequent substitution reactions for example as a triflate	i	5635	Go
addition reaction step	A reaction in which two or more groups of atoms are added to the molecule, resulting in a change of skeletal bond order.	i	17	Go
Addition–elimination reaction	Any reaction involving a nucleophilic addition followed by an elimination reaction (Wikipedia)	i	2	Go
AES dehalogenation	Replacement of an aromatic halogen by hydrogen. Reagents: Friedel-Crafts catalysts, catalytic hydrogenation. Source: March 1-45	i	778	Go
aldehyde reduction	A reduction in which an aldehyde is reduced to form a primary alcohol.	i	3004	Go
aldol addition	A carbon-carbon coupling reaction where an enol or enolate reacts with a carbonyl compound to form a beta-hydroxy ketone. The name comes from aldehyde + alcohol.	i	64	Go
aldol condensation	An aldol addition where an enol or enolate reacts with a carbonyl compound to form an alpha,beta-unsaturated ketone.	i	23	Go
Aliphatic dehalogenation	Reduction of alkyl halides with dehydrohalogenation. Hydro-de-halogenation (March 0.77)	i	151	Go
Aliphatic nucleophilic substitution	Reaction of a nucleophile for example a bromine anion with an aliphatic substrate with a good leaving group	i	14089	Go
Aliphatic nucleophilic substitution at activated oxygen	Reaction of a nucleophile with an activated oxygen electrophile, for example a tosylate or mesylate	i	1109	Go
Alkene dehydrohalogenation	Conversion of an vinyl halide to an alkyne (March 7.14)	i	53	Go
alkene metathesis	A joining reaction in which two carbon-carbon double bonds are redistributed among two fragments, i.e. two alkenes. It is typically catalysed by a metal carbenoid, and proceeds via two four-membered intermediates (metallacyclobutanes). The reaction is driven by release of a low-MW alkene.	i	3	Go
alkene ozonolysis	An alkene oxidation where the reagent is ozone and the product is the corresponding ozonide.	i	1	Go
alkene reduction to alkane	A hydrogenation reaction where an alkene is reduced to an alkane.	i	2	Go
Alkylation at active-hydrogen alpha carbon	Alkylation reaction on substrates carrying a carbon atom with active hydrogen of the type Z-CH2-Z. Malonic ester synthesis excluded. Source: March 0-96	i	89	Go
Alkylation of ketones, nitriles and esters	Alkylation by alkyl halides of ketones, esters and nitriles at alpha carbon position. requires strong base. With carbonyl groups the enolate conjugate base is involved Source: March 0-97	i	1429	Go
Alkyne 1,2-addition	1,2-additions over an alkyne by amines and alcohols to form enamines and enols	i	47	Go
Alkyne deprotection	Alkyne deprotection with removal of trimethylsilyl group.	i	1429	Go
Alkyne to alkene reduction	Any reaction reducing an alkyne to an alkene	i	125	Go
Alkyne trimerisation	a [2+2+2]cycloaddition reaction in which three alkyne units react to form a benzene ring, requires a catalyst. Source: Wikipedia	i	3	Go
alkyne-azide click reaction	A [3+2] cycloaddition reaction between an azide and an alkyne to give a 1,2,3-triazole, needing only heat to proceed.	i	152	Go
Amide dehydration to a nitrile	Conversion of an amide to a nitrile, commonly with phosphorus pentoxide (March 7.42)	i	1880	Go
Amide hydrolysis	Amide hydrolysis other than BOC deprotection, amine group retained or carboxylic acid group retained	i	2290	Go
amide reduction to amine	A reduction process where an amide is transformed into an amine.	i	2098	Go
amination	Formation of a covalent bond between a substrate and an amino group.	i	1925	Go
Amine salt formation	Amines react with acids (HCl, carboxylic acids) to form ammonium salts. (Source: Wikipedia)	i	4	Go
amino group deprotection	A deprotection reaction where the reactive centre is an amino nitrogen atom e.g. tert-butylsulfinyl, BOC deprotection excluded.	i	11332	Go
amino group protection	A protection reaction where the reactive centre is an amino nitrogen atom.	i	1297	Go
Appel bromination	Conversion of an alcohol to an alkyl bromide with triphenylphosphine and tetrabromomethane or bromine.	i	1740	Go
Appel chlorination	Conversion of an alcohol to an alkyl chloride with triphenylphosphine and tetrachloromethane.	i	123	Go
Appel iodination	Conversion of an alcohol to an alkyl iodide with triphenylphosphine and tetraiodomethane.	i	327	Go
Aromatic amino-de-halogenation	Reaction of an aryl halide with an amine catalysed by copper or nickel. (March 3-6)	i	1322	Go
Aromatic halogen exchange reaction	Any reaction converting an aromatic bromide or chloride to an aromatic iodide	i	370	Go
Aromatic nitration	A reaction that adds a nitro group to an aromatic ring involving an nitronium ion	i	2500	Go
Aromatization	Any reaction in which an aromatic system is formed from a single nonaromatic ringsystem. Source: Wikipedia	i	1	Go
Aryl-aryl Grignard coupling	A reaction of an aryl Grignard reagent with an aryl halide forming an aryl - aryl coupling adduct	i	55	Go
aza-Diels-Alder reaction	A Diels-Alder reaction between a diene and an imine or an azadiene and an alkene to give a six-membered nitrogen-containing ring compound.	i	2	Go
aza-Wacker cyclisation	A cyclisation where an amino group acts as the nucleophile in a Wacker-Tsuji oxidation accompanied by beta-hydride elimination, forming a ring.	i	1	Go
Azido-de-diazoniation	Conversion of an diazonium salt to an azide by the addition of sodium azide (March 3-23)	i	1	Go
Baeyer-Villiger oxidation	A reaction of a ketone to give an ester, in which an alkyl, benzyl or phenyl group migrates from one of the alpha-carbon centres to an adjacent oxygen, displacing an oxygen-based leaving group; the result is a formal insertion of an oxygen atom. The reaction also works with aldehydes, giving the corresponding carboxylic acid. The term "Baeyer-Villiger rearrangement" may occasionally be used in a mechanistic sense to refer specificially to the actual rearrangement step.	i	31	Go
Bamford-Stevens reaction	The reaction of a tosylhydrazone of an aldehyde or ketone with a strong base to give an olefin.	i	10	Go
Barton decarboxylation	The decarboxylation of a carboxylic acid to the lower homologue alkane using a pyridine thione.	i	1	Go
Barton-McCombie deoxygenation	The deoxygenation of an alcohol to the corresponding alkane using a thiochloroformate. It proceeds by a radical mechanism.	i	25	Go
Baylis-Hillman reaction	A carbon-carbon coupling of an aldehyde to an activated alkene in the presence of a nucleophilic base to give an alpha-hydroxyalkylated compound.	i	2	Go
Beckmann rearrangement	A rearrangement where an oxime rearranges to form an amide. Often there is selective migration of one group.	i	31	Go
Benzyl alcohol reduction	Reduction of an aromatic methyl alcohol group to a methyl group	i	14	Go
benzylamine deprotection	An amino group deprotection reaction where a benzylamine group is removed by hydrogenation.	i	173	Go
Bischler-Napieralski reaction	A cyclodehydration of a beta-phenethylamide to give a 3,4-dihydroisoquinoline.	i	111	Go
Boc deprotection	An amino group deprotection reaction where a tertbutoxycarbonyl group is removed in acid conditions.	i	44748	Go
Boc protection	A protection reaction in which an amine is converted into a tert-butoxycarbonyl compound.	i	4316	Go
bromo Heck-type reaction	A Heck-type reaction where an organobromide couples to a terminal olefin to produce an internal olefin.	i	646	Go
bromo Sonogashira coupling	A Sonogashira coupling where the aryl halide is an aryl bromide.	i	1161	Go
bromo Suzuki coupling	A Suzuki coupling where the halide is a bromide.	i	26624	Go
Buchwald-Hartwig amination	A reaction in which an aryl halide or aryl triflate reacts with a primary or secondary amine in the presence of base to give a secondary or tertiary amine. It is catalysed by a palladium catalyst.	i	13376	Go
C-H activation	A type of organic reaction in which a carbon–hydrogen bond is cleaved and replaced with a C-C, C-O or C-N bond in the presence of a transition metal (Source: Wikipedia)	i	1	Go
Carbene reaction	Any reaction involving a carbene as reactive intermediate	i	4	Go
carbon-carbon coupling reaction	A reaction where a bond is formed between two carbon atoms.	i	2	Go
carbonyl compound to imine conversion	A functional group modification where a carbonyl compound is converted to an imine. With an α-carbonyl proton present the reaction product is an enamine (Alkylimino-de-oxo-bisubstitution)	i	7156	Go
carbonyl group protection	A protection reaction where the reactive centre is a carbonyl oxygen	i	180	Go
Carbonyl thiation	Conversion of carbonyl compound to thioketone, with for example Lawesson's reagent	i	1074	Go
carboxy group deprotection	A deprotection reaction where the reactive centre is a carboxy oxygen atom.	i	1885	Go
Carboxylate salt formation	Carboxylic acids react with bases to form carboxylate salts, in which the hydrogen of the hydroxyl (–OH) group is replaced with a metal cation. (Source: Wikipedia)	i	517	Go
carboxylic acid benzyl ester deprotection	carboxylic acid benzyl ester deprotection, for example with hydrogen / palladium	i	1771	Go
carboxylic acid to acid chloride conversion	A functional group modification where a carboxylic acid is converted to an acid chloride.	i	3545	Go
carboxylic acid to primary alcohol reduction	A carboxylic acid reduction where the product is the corresponding primary alcohol.	i	3163	Go
Chan-Lam coupling	Arylation of an amine or an alcohol with an arylboronic acid, stannane or siloxane in air with a copper acetate catalyst.	i	181	Go
chloro Heck reaction	A Heck reaction where an organochloride couples to a terminal olefin to produce an internal olefin, catalysed by palladium.	i	37	Go
chloro Sonogashira coupling	A Sonogashira coupling where the aryl halide is an aryl chloride.	i	188	Go
chloro Suzuki coupling	A Suzuki coupling where the halide is a chloride.	i	10134	Go
Chugaev reaction	Elimination of a water molecule from a secondary alcohol to yield an olefin.	i	1	Go
Claisen rearrangement	The [3,3]-sigmatropic rearrangement of an allyl vinyl ether to give a gamma,delta-unsaturated carbonyl compound.	i	3	Go
Clemmensen reduction	A functional group reduction where an aldehyde or ketone carbonyl group is reduced to a methylene with zinc-mercury amalgam and hydrochloric acid.	i	2	Go
Colvin Rearrangement	homologization and addition of lithiated TMS diazomethane to aldehydes to form an alkyne	i	1	Go
conjugate addition	A joining reaction where a nucleophile adds to the beta-carbon of an alpha,beta-unsaturated system (or an activated carbon-carbon bond).	i	1	Go
copper(I)-catalyzed azide-alkyne cycloaddition	A [3+2] cycloaddition reaction between an azide and an alkyne to give a 1,2,3-triazole as a single regioisomer.	i	311	Go
Corey-Bakshi-Shibata reduction	Enantioselective reduction of a ketone to an alcohol with a chiral oxazaborolidine.	i	24	Go
Corey-Fuchs reaction	A homologation reaction of an aldehyde to yield a terminal alkyne. The reagents are tetrabromomethane, triphenylphosphine, butyllithium and water.	i	73	Go
cross-coupling	A joining reaction where a carbon-carbon bond is formed between unlike moieties.	i	1	Go
Curtius rearrangement	A rearrangement of an acyl azide to give an isocyanate by pyrolysis, with the elimination of molecular nitrogen. The isocyanate may or may not be intercepted by a nitrogen or oxygen nucleophile	i	100	Go
cyanoacetic ester synthesis	Alkylation reaction of alkyl halides with compounds containing an alpha carbon flanked by a ester and a cyano group. Variation of malonic ester reaction. Source: March 0-96	i	43	Go
Cyclopropanation	Any substitution reaction in which a cyclopropane ring is created.	i	355	Go
Deacetylation	The removal of a (protective) acetyl group, leaving an hydroxyl group. Source: Wikipedia	i	2684	Go
decarboxylation	Breaking of a covalent bond between a molecule and a carboxy group.	i	793	Go
dehalogenation	Breaking of a covalent bond between a substrate and a halo group.	i	1	Go
Dehydrohalogenation	dehydrohalogenation is an elimination reaction which removes a hydrogen halide from a substrate. The reaction is usually associated with the synthesis of alkenes, but it has wider applications.	i	40	Go
Demethylation at oxygen	Any reaction converting a methoxy group to an hydroxyl group with demethylation	i	11129	Go
deprotection reaction	A reaction in which a protecting group is modified by converting it into a functional group.	i	1	Go
Dess-Martin aldehyde oxidation	A Dess-Martin oxidation of a primary alcohol to an aldehyde.	i	2760	Go
Dess-Martin ketone oxidation	A Dess-Martin oxidation of a secondary alcohol to a ketone.	i	1144	Go
Dess-Martin oxidation	The oxidation of a primary alcohol to an aldehyde or a secondary alcohol to a ketone using the Dess-Martin periodinane.	i	1	Go
diazotisation	A functional group oxidation where an aromatic amine is transformed into an aromatic diazonium salt.	i	61	Go
Dieckmann cyclisation	An intramolecular cyclisation of a diester to give a cyclic beta-ketoester.	i	70	Go
Diels-Alder reaction	A [4+2] cycloaddition reaction where a diene reacts with a compound containing a double or triple bond (a dienophile) to form an unsaturated six-membered ring compound.	i	3	Go
Difluoromethoxylation and trifluoromethoxylation	Any reaction introducing a difluoromethoxy group or a trifluoromethoxy group into a molecule. Both functional groups are relevant to medicinal chemistry	i	2	Go
difluoromethyl group addition	Addition of an difluoromethyl group at nitrogen, oxygen or carbon	i	353	Go
Einhorn–Brunner reaction	the chemical reaction of imides with alkyl hydrazines to form an isomeric mixture of 1,2,4-triazoles. (Source: Wikipedia)	i	7	Go
Electrophilic decarboxylative halogenation	A type of electrophilic aromatic substitution with a halogenation donor reagent accompanied by decarboxylation	i	91	Go
Electrophilic halogenation	Type of electrophilic substitution reaction, replacing a hydrogen atom for a halide, usually catalysed by a Lewis acid.	i	16975	Go
electrophilic methylation	Electrophilic methylations are commonly performed using electrophilic methyl sources such as iodomethane, dimethyl sulfate, dimethyl carbonate, or tetramethylammonium chloride (Source: Wikipedia)	i	1947	Go
elimination reaction	A molecular process where two groups are lost with concomitant formation of an unsaturation in the molecule or formation of a new ring.	i	1873	Go
enamine - imine tautomerization	tautomerization reaction of an enamine to an imine. For example as result of N-Boc deprotection	i	118	Go
ene reaction	A joining reaction where an alkene with an allylic hydrogen reacts with a compound containing a multiple bond (an enophile) to form a substituted alkene.	i	3	Go
Epoxy-ring opening	Ring-openings reaction of an epoxide with N,S,O nucleophiles	i	760	Go
ester reduction	A reduction process where the oxidation state carbonyl carbon in the ester functionality is reduced. Reduction to aldehyde not included	i	10305	Go
ester reduction to aldehyde	An ester reduction where the product is the corresponding aldehyde.	i	672	Go
ethyl ester deprotection	A deprotection reaction where the reactant is an ethyl ester and the product is a carboxylic acid.	i	16738	Go
Evans−Tishchenko reduction	is the diastereoselective reduction of β-hydroxy ketones to the corresponding 1,3-anti diol monoesters. The reaction employs a Lewis acid, often samarium iodide, and an aldehyde.	i	1	Go
extrusion reaction	A cleaving reaction in which a skeletal atom or group of atoms is removed from the middle of a molecule.	i	1	Go
Favorskii reaction	A reaction between an alkyne and a carbonyl group under basic conditions in which a terminal alkyne serves as the CH-acidic moiety. When the carbonyl is an aldehyde, the 'Favorskii rearrangement' (RXNO:0000385) takes place and leads to an enone	i	77	Go
Feist-Bénary synthesis	Reaction of an alpha-haloketone or alpha-haloether with a 1,3-dicarbonyl compound in the presence of pyridine to yield a substituted furan.	i	202	Go
Fiesselmann thiophene synthesis	allows for the generation of 3-hydroxy-2-thiophenecarboxylic acid derivatives from α,β-acetylenic esters with thioglycolic acid and its derivatives under the presence of a base	i	2	Go
Fischer indole synthesis	Reaction of an aldehyde or ketone with a phenylhydrazine to give an indole.	i	6	Go
Fischer-Speier esterification	The esterification of a carboxylic acid with an alcohol. Various Lewis acids or Bronsted acids may be used as catalyst.	i	9028	Go
Fleming-Tamao oxidation	The stereospecific oxidation of a (phenyldimethylsilyl)alkane to the corresponding alcohol using bromine, usually generated in situ from potassium bromide and peracetic acid.	i	3	Go
Formamide dehydration to isonitrile	Formamide dehydration to isonitrile to form an isonitrile (CNC), usual reagents POCl3 or Burgess reagent	i	38	Go
formylation	Formation of a covalent bond between a substrate and a formyl group.	i	1	Go
Free amine formation	Reaction with base to a free amine from an ammonium salt with acids (HCl, carboxylic acid). (Source: Wikipedia)	i	1	Go
Friedel-Crafts acylation	A carbon-carbon coupling reaction between an arene and a carbonyl compound (usually an acyl halide) to give an aryl ketone. The reaction is catalysed by a Lewis acid.	i	1120	Go
Friedel-Crafts alkylation	A carbon-carbon coupling reaction between an arene and an alkyl halide/alkene/alcohol (anything that can form a carbocation) to give a substituted arene. The reaction is catalysed by a Lewis acid.	i	224	Go
Friedel-Crafts reaction	A carbon-carbon coupling reaction between an arene and a carbonyl compound (an acylation) or an alkyl compound that can form a carbocation (an alkylation) to form a substituted arene.	i	1	Go
functional group oxidation	A functional group modification reaction where a functional group is oxidised.	i	1	Go
functional group reduction	A functional group modification reaction where a functional group is reduced.	i	1	Go
Giese reaction	hydroalkylation process by the addition of nucleophilic radicals to electron-poor olefins.	i	3	Go
Giese-Baran cyclization		i	2	Go
Grignard reaction	A carbon-carbon coupling reaction where a Grignard reagent reacts with a compound containing an electrophilic carbon atom. A Grignard reagent is a magnesium-stabilised carbon nucleophile. An aldehyde leads to a secondary alcohol, a ketone leads to a tertiary alcohol, an ester leads to a ketone and a nitrile leads to a ketone.	i	4480	Go
Groebke–Blackburn–Bienaymé reaction	GBBR reaction, synthesis of a fused imidazole based on a multicomponent reaction of an aldehyde, isocyanide and amidine	i	1	Go
Halogen dance	Rearrangement of polyhaloaryls with strong base. March 1-45	i	1	Go
halogenation	Formation of a covalent bond between a substrate and a halo group.	i	6	Go
Halogenation of 2-hydroxy-N-heterocycles	Conversion of 2-hydroxypyridines to 2-halopyridines with reagents such as POCl3	i	1753	Go
Hantzsch pyridine synthesis	A ring-forming reaction between two equivalents of a beta-ketoester, an aldehyde and ammonia (or an ammonium salt), to give a dihydropyridine. The dihydropyridine can be oxidised to a pyridine using an oxidising agent.	i	2	Go
Hauser-Kraus annulation	an anthraquinone forming reaction from a fused lactone and an alkene.	i	1	Go
Heck reaction	A carbon-carbon coupling reaction where an organohalide or triflate couples to a terminal olefin to produce an internal olefin, catalysed by palladium. It is stereospecific.	i	145	Go
Heck-type reaction	A carbon-carbon coupling reaction where an organohalide or triflate couples to a terminal olefin to produce an internal olefin.	i	1	Go
Hell-Volhard-Zelinsky reaction	An alpha-halogenation reaction where a carboxylic acid reacts with dibromine to form an alpha-bromocarboxylic acid.	i	17	Go
Henry reaction	A carbon-carbon coupling reaction between a nitroalkane and an aldehyde or ketone to give a beta-hydroxy nitroalkane.	i	5	Go
Hofmann reaction	Conversion of a primary carboxylic amide to the lower homologue primary amine. The first step is the Hofmann rearrangement	i	6	Go
Homologation reaction	any reaction converting a reactant into the next member of a homologous series for example extension of a chain by a methylene group. Source: Wikipedia	i	1	Go
homolytic aromatic substitution	Aromatic substitution involving radical species (HAS)	i	1	Go
Horner-Wadsworth-Emmons reaction	A carbon-carbon coupling reaction between a phosphonate and a carbonyl compound to give an olefin.	i	263	Go
Hunsdiecker reaction	The decarboxylation of silver carboxylates with halogens to give organic halides.	i	1	Go
hydroamination	The addition of the N-H bond of an amine across a double bond of an alkene or alkyne, to give a more substituted amine.	i	660	Go
hydroboration	The addition of a boron hydride across a double bond of an alkene or alkyne. The boron usually adds to the less substituted carbon.	i	41	Go
hydroboration-oxidation	The formal addition of water across a double bond of an alkene or alkyne by formation of an organoborane and in situ oxidation, typically with basic peroxide. The product is usually the less substituted alcohol.	i	2	Go
hydrogenation	A reduction process that involves addition of hydrogen atoms across a double bond.	i	8166	Go
Hydrogenolysis	A reaction in which a carbon–carbon or carbon–heteroatom single bond is cleaved or undergoes lysis (breakdown) by hydrogen (source: Wikipedia).	i	605	Go
hydrostannylation	The reaction of a organotin hydride with an alkene or alkyne, to give an intermediate tin species that can give various products after work-up.	i	38	Go
hydroxy group deprotection	A deprotection reaction where the reactive centre is an oxygen atom.	i	12926	Go
hydroxyl group protection	A protection reaction where the reactive centre is a hydroxyl oxygen atom.	i	670	Go
hydrozirconation	The reaction of a organozirconium hydride with an alkene or alkyne, to give an intermediate zirconium species that can give various products after work-up. The zirconium reagent used is typically Schwartz's reagent, Cp2ZrHCl.	i	1	Go
imidazole synthesis	A planned reaction in which one of the products contains an imidazole system that was not in any of the reactants.	i	1471	Go
Intramolecular condensation imidazoline	Any condensation reaction that creates a imidazoline ring from a linear chain	i	50	Go
Intramolecular condensation thiazoline	Any condensation reaction that creates a thiazoline ring from a linear chain	i	36	Go
intramolecular Prins reaction	A reaction between formaldehyde and an alkene to give a 1,3-dioxane, catalysed by acid.	i	1	Go
inverse electron-demand Diels–Alder reaction	IEDDA, a cycloaddition between an electron-rich dienophile and an electron-poor diene. Source: Wikipedia	i	1	Go
iodo Heck reaction	A Heck reaction where an organoiodide couples to a terminal olefin to produce an internal olefin, catalysed by palladium.	i	201	Go
iodo Sonogashira coupling	A Sonogashira coupling where the aryl halide is an aryl iodide.	i	1217	Go
iodo Suzuki coupling	A Suzuki coupling where the halide is an iodide.	i	5347	Go
Isocyanate synthesis	Isocyanate synthesis (R=N=C=O) from amines and amides with phosgene. (Source: Wikipedia)	i	129	Go
Johnson-Corey-Chaykovsky cyclopropane synthesis	Reaction of a sulfur ylide with an olefin to produce a cyclopropane.	i	3	Go
Johnson-Corey-Chaykovsky epoxide synthesis	Reaction of a sulfur ylide with a ketone to produce an epoxide.	i	66	Go
Jones oxidation	An oxidation reaction where an alcohol is oxidized to the corresponding carbonyl compound by a dichromate ion.	i	543	Go
keto to enol ether transformation	Conversion of an ketone or aldehyde to a enol ether. May be accompanied by secondary etherfication or esterification	i	762	Go
Ketone halogenation	Ketones can be halogenated at the alpha position with bromine, chlorine or iodine to form a haloketone, also possible with aldehydes. (Source: March 2-4)	i	1966	Go
ketone reduction	A reduction process where a ketone is reduced to a secondary alcohol.	i	5584	Go
Knoevenagel condensation	A carbon-carbon coupling reaction of an aldehyde and a methylene compound.	i	2	Go
Knorr pyrazole synthesis	Synthesis of a pyrazole by condensation of a 1,3-dicarbonyl compound with a hydrazine, hydrazide, semicarbazide or aminoguanidine.	i	231	Go
Kolbe electrolysis	The decarboxylation and coupling of a carboxylate or mixture of carboxylates to give a dimer.	i	1	Go
Krische allylation	Enantioselective addition reaction of an allyl group to an aldehyde or an alcohol, resulting in a secondary homoallylic alcohol. Source: Wikipedia	i	1	Go
Lactam forming reaction	Any intramolecular reaction forming a lactam (cyclic amide) 5,6-membered ring. Source: WIkipedia	i	2999	Go
Lactone forming reaction	Any reaction forming a lactone, for example intramolecular esterification	i	61	Go
Larock indole synthesis	Palladium-catalysed synthesis of a 2,3-substituted indole by reaction of an ortho-iodoaniline with an internal alkyne.	i	3	Go
Lemieux-Johnson oxidation	A cleaving reaction where an olefin is dihydroxylated with osmium tetroxide and undergoes a Malaprade reaction to yield two aldehydes, two ketones, or an aldehyde and a ketone.	i	425	Go
Ley oxidation	The use of Tetrapropylammonium perruthenate in the oxidation of a primary alcohol to an aldehyde.	i	173	Go
Liebeskind-Srogl coupling	A cross-coupling reaction where a thioester and a boronic acid react to form a ketone. It uses a metal catalyst.	i	1	Go
Luche reduction	The chemoselective reduction of an enone to give an allylic alcohol, using sodium borohydride and an lanthanoid chloride, typically cerium chloride.	i	6	Go
malonic ester synthesis	A carbon-carbon coupling reaction between a dialkyl malonate and an alkyl or aryl halide, to give a substituted acetic acid. The base/RX treatment can be repeated to give a disubstituted product.	i	451	Go
Mannich reaction	A carbon-carbon coupling reaction where ammonia or an amine reacts with a non-enolisable aldehyde, often methanal, and an enolisable carbonyl compound to form a beta-amino carbonyl compound.	i	2	Go
Matteson Homologation	Synthesis of alpha-halo boronic ester from an boronic ester and a dihalomethyl compound	i	6	Go
McLoughlin-Thrower reaction	Coupling reaction and trifluoromethylation using iodofluoroalkanes, iodoaromatic compounds and copper. Source: Wikipedia	i	68	Go
Meerwein-Ponndorf-Verley reduction	A reduction of an aldehyde or ketone to an alcohol involving an equilibrium between the aldehyde or ketone and a reagent alcohol present in excess, catalysed by a metal alkoxide. This reaction is the reverse of the Oppenauer oxidation (RXNO:0000047).	i	1	Go
Meerwein-Ponndorf-Verley reduction of a ketone	Meerwein-Ponndorf-Verley reduction of a ketone to the corresponding secondary alcohol.	i	1	Go
Menshutkin reaction	The alkylation of a tertiary amine with an alkyl halide to the corresponding ammonium salt.	i	636	Go
methyl ester deprotection	A deprotection reaction where the reactant is a methyl ester and the product is a carboxylic acid.	i	22385	Go
Michael addition	A conjugate addition reaction where a carbon nucleophile adds to the beta-carbon of an alpha,beta-unsaturated system (or an activated carbon-carbon bond).	i	7	Go
Milas dihydroxylation	Conversion of alkene to vicinal diol with use of stoichiometric amount of peroxide.	i	7	Go
Mitsunobu reaction	A substitution where an alcohol is converted into something else. Typical reagents are a dialkyl azodicarboxylate and a triarylphosphine. The alcohol stereocentre is inverted.	i	6537	Go
Miyaura borylation	A chemical reaction that allows the generation of boronates from vinyl or aryl halides with the cross-coupling of bis(pinacolato)diboron under basic conditions	i	1970	Go
Mukaiyama aldol addition	An aldol addition between an aldehyde or ketone and a silyl enol ether (also known as a ketene silyl acetal) to give a beta-hydroxy carbonyl compound.	i	1	Go
Mukaiyama hydration	The Mukaiyama hydration is an organic reaction involving formal addition of an equivalent of water across an alkene by the action of catalytic bis(acetylacetonato)cobalt(II) complex, phenylsilane and atmospheric oxygen	i	13	Go
N-acylation to amide	An acylation reaction where a nitrogen atom is acylated to form an amide.	i	1	Go
N-acylation to carbamate	An N-acylation reaction where a nitrogen centre is acylated to form a carbamate.	i	314	Go
N-alkylation	Formation of a covalent bond between a nitrogen atom in a substrate and an alkyl group.	i	27449	Go
N-hydro-C-cyano-addition	Any Reaction with cyanide ion adding to mines, Schiff bases , hydrazine's and similar compounds (March 3rd 6.51)	i	33	Go
Nazarov cyclisation	The acid-catalysed cyclisation of a divinylketone to give a cyclopentenone.	i	1	Go
Negishi coupling	A carbon-carbon coupling reaction between an organohalide or organotriflate and an organozinc compound. The reaction is catalysed by palladium or nickel.	i	20	Go
nitration	Formation of a covalent bond between a substrate and a nitro group.	i	1	Go
Nitrene reaction	Reaction involving a nitrene reactive intermedaiate	i	2	Go
Nitrile hydrolysis to acetamide	Nitrile hydrolysis to acetamide	i	2306	Go
Nitrile reduction to aldehyde	Any reduction converting a nitrile to the corresponding aldehyde	i	486	Go
nitrile reduction to amine	A reduction where a nitrile is replaced by an amine function.	i	3394	Go
nitro reduction to amine	A reduction reaction where a nitro group is reduced to an amino group.	i	23598	Go
nitro-Michael reaction	A conjugate addition reaction where a carbon nucleophile adds to an alpha,beta-unsaturated nitro compound.	i	3	Go
Nitrogen phosphorus bond formation	Formation of any new bond between nitrogen and phosphorus	i	13	Go
Norrish reaction	is the photochemical cleavage or homolysis of aldehydes and ketones into two free radical intermediates (α-scission). (Source Wikipedia)	i	1	Go
Noyori asymmetric hydrogenation, alkene	The homogeneous asymmetric catalytic hydrogenation of a C=C double bond using a ruthenium(II) BINAP catalyst.	i	3	Go
Noyori asymmetric hydrogenation, carbonyl	The homogeneous asymmetric catalytic hydrogenation of a carbonyl bond using a ruthenium(II) BINAP catalyst.	i	1	Go
Nozaki-Hiyama-Kishi reaction	A coupling reaction of an aldehyde to an allyl, vinyl or aryl halide or triflate in the presence of chromium(II). It is catalysed by nickel.	i	1	Go
Nucleophilic addition	an addition reaction where a chemical compound with an electrophilic double or triple bond reacts with a nucleophile, such that the double or triple bond is broken. (Source: Wikipedia)	i	1323	Go
nucleophilic aromatic substitution	a substitution reaction in which a N or O nucleophile displaces a good leaving group, such as a halide, on an electron deficient aromatic ring. Nucleophile can also be Sn,F (source: Wikipedia)	i	28111	Go
Nucleophilic aromatic substitution at N-heterocycles	Nucleophilic aromatic substitution at N-heterocycles (pyridine, pyrimidine) with N-nucleophiles or O-nucleophiles or S-nucleophiles. Metal free.	i	30510	Go
nucleophilic aromatic substitution with S-nucleophiles	a substitution reaction in which an sulfur nucleophile displaces a good leaving group, such as a halide, on an electron deficient aromatic ring.	i	165	Go
O-silyl deprotection	Reaction involving the removal of a silyl protective group, e.g. TMS, TES,TBS, TIPS, TBDPS	i	5465	Go
O-silylation	Formation of a covalent bond between an oxygen atom in a substrate and a silyl group.	i	5	Go
Oppenauer oxidation	An oxidation of a secondary alcohol to a ketone involving an equilibrium between the alcohol and a reagent ketone present in excess, catalysed by a metal alkoxide.	i	1	Go
Organocopper incorporating reaction	Any reaction introducing an organocopper bond in a substrate	i	1	Go
Organogermanium incorporating reaction	Any reaction introducing an organogermanium bond in a substrate	i	4	Go
organometallic methylene-de-oxo-substitution	Any organometallic reaction converting a ketone to the corresponding methylene, reagents Tebbe, Nysted, Petasis	i	14	Go
Organophosphonium compound synthesis	Synthesis of phosphonium salts from phosphines and alkyl halides. Usually step preceding a Witting reaction	i	294	Go
Organosilicon incorporating reaction	Any reaction introducing an organosilicon bond in a substrate	i	3	Go
Organotin incorporating reaction	Any reaction introducing an organotin bond in a substrate	i	2	Go
Organozinc incorporating reaction	Any reaction introducing an organozinc bond in a substrate	i	1	Go
oxidation at sulfur	An oxidation process where the oxidation state of at least one sulfur atom increases.	i	4992	Go
oxy-Cope rearrangement	A [3,3]-sigmatropic rearrangement of a 3-hydroxy-1,5-hexadiene rearranges to form a 5,6-unsaturated carbonyl compound.	i	1	Go
P-alkylation	The formation of a covalent bond between a phosphorus atom and an alkyl group.	i	10	Go
Paal-Knorr furan synthesis	The cyclisation of a 1,4-dicarbonyl compound with an acid catalyst to give a furan.	i	15	Go
Paal-Knorr pyrrole synthesis	The cyclisation of a 1,4-dicarbonyl compound with an amine to give a pyrrole.	i	392	Go
Paal-Knorr thiophene synthesis	The cyclisation of a 1,4-dicarbonyl compound with phosphorus pentasulfide to give a thiophene.	i	18	Go
Parikh–Doering oxidation	an oxidation reaction that transforms primary and secondary alcohols into aldehydes and ketones, respectively. The procedure uses dimethyl sulfoxide (DMSO) as the oxidant and the solvent, activated by the sulfur trioxide pyridine complex (SO3•C5H5N) in the presence of triethylamine or diisopropylethylamine as base (source: Wikipedia).	i	16	Go
Passerini reaction	The reaction between an isonitrile, a carboxylic acid and aldehyde or ketone to give an alpha-acyloxy amide.	i	1	Go
Pechmann pyrazole synthesis	Reaction of an organic diazo compound with an acetylene to yield a pyrazole.	i	48	Go
Pellizzari reaction	the organic reaction of an amide and a hydrazide to form a 1,2,4-triazole. (Source: Wikipedia)	i	1	Go
Peptide coupling reaction	A reaction between an carboxylic acid or ester and an amine forming an amide, often aided by dedicated coupling reagents	i	69151	Go
Peterson olefination	A carbon-carbon coupling reaction in which an alpha-silyl carbanion reacts with an aldehyde or a ketone to give an alkene, proceeding via a beta-hydroxysilane. The stereochemistry of the alkene can be controlled by treating the intermediate with acid or base.	i	10	Go
phthalimide ring synthesis	Any ring-forming reaction involving the completion of a phthalimine unit	i	319	Go
Pictet-Spengler reaction	A condensation-cyclisation of a beta-phenethylamine with an aldehyde to give a tetrahydroisoquinoline.	i	2	Go
pinacol rearrangement	A rearrangement of a 1,2-diol to give a carbonyl compound, catalysed by acid.	i	1	Go
Pinner triazine synthesis	Reaction of aryl amidines or halogenated aliphatics amidines with phosgene to yield a 2-hydroxy-4,6-diaryl-s-triazine with loss of ammonia.	i	2	Go
Pinnick oxidation	oxidation of an aldehyde to the corresponding carboxylic acid using sodium chlorite. Source: Wikipedia	i	468	Go
Prilezhaev epoxidation	Epoxidation of an alkene by reaction with a peroxy acid.	i	471	Go
primary alcohol oxidation to aldehyde	An oxidation process where a primary alcohol is transformed into an aldehyde.	i	1726	Go
Primary amide synthesis	Primary amide synthesis from a carboxylic acid and ammonia.	i	2300	Go
Prins reaction	A carbon-carbon coupling between formaldehyde and an alkene to give a 1,3-diol or an allylic alcohol, catalysed by acid.	i	1	Go
Propargylic nucleophilic addition to an aldehyde	Nucleophilic addition reaction subset with an alkyne reactant reacting with an aldehyde forming a propargylic alcohol	i	66	Go
pyrazole synthesis	A reaction in which the intended product is a pyrazole that was not present in any of the reactants.	i	840	Go
pyrimidine synthesis	A reaction in which the intended product is a pyrimidine that was not present in any of the reactants.	i	3	Go
pyrrole reduction	Partial or complete reduction of a pyrrole to a dihydropyrrole or a pyrrolidine with a reducing agent	i	475	Go
pyrrole synthesis	A reaction in which the intended product is a pyrrole that was not present in any of the reactants.	i	113	Go
Quaternary carbon center synthesis	Any reaction adding a queternary carbon center to the scaffold	i	99	Go
rearrangement step	A reaction which preserves the number of rings and number of skeletal atoms and in which the molecule rearranges so that one or more atoms or groups of atoms move from one atom to another.	i	1	Go
Reduction of azides, isocyanates to amines	Azides can be reduced to primary amines, isocyanates and isothiocyanate to methyl amines (March 9.15)	i	2	Go
Reduction of nitroso & hydroxylamine compounds	Reduction of nitroso compounds and hydroxylamines to amines. (March 9-51)	i	1	Go
reductive amination	A functional group modification where a carbonyl oxygen is replaced by an amine.	i	15478	Go
reductive dimerization	Any coupling reaction and dimerization of two aryl or alkenyl halides to form a new unsaturated carbon-carbon bond, catalysed by metals such as zinc and copper	i	1	Go
Reformatsky reaction	A carbon-carbon coupling reaction where an aldehyde or amine reacts with a alpha-halo ester and zinc to form a beta-hydroxy ester.	i	1	Go
Riley oxidation	is a selenium dioxide-mediated oxidation of methylene groups adjacent to carbonyls (source: Wikipedia).	i	65	Go
ring breaking	A planned reaction step in which the product has fewer rings than the reactants.	i	2	Go
ring contraction	A planned reaction step in which an existing ring is reduced in size.	i	1	Go
ring expansion	A reaction in which an existing ring is increased in size.	i	2	Go
ring rearrangement	A reaction in which the number of rings in a molecule stays the same but the connectivity of the atoms in at least one ring changes.	i	1	Go
ring-closing metathesis	A joining reaction in which two carbon-carbon double bonds in the same molecule are redistributed to give a cycloalkene. It is typically catalysed by a metal carbenoid, and proceeds via two four-membered intermediates (metallacyclobutanes). The reaction is driven by release of a low-MW alkene.	i	348	Go
ring-opening metathesis	A ring-breaking reaction in which two carbon-carbon double bonds are redistributed among two fragments, i.e. an alkene and a cycloalkene. It is typically catalysed by a metal carbenoid, and proceeds via two four-membered intermediates (metallacyclobutanes). The reaction is driven by release of ring strain in the cycloalkene.	i	1	Go
Robinson–Gabriel synthesis	an organic reaction in which a 2-acylamino-ketone reacts intramolecularly followed by a dehydration to give an oxazole (Wikipedia).	i	198	Go
Rosenmund-von Braun reaction	A carbon-carbon coupling reaction where an aryl halide reacts with copper(I) cyanide to give an aryl nitrile.	i	3327	Go
Rubottom oxidation	The Rubottom oxidation is a useful, high-yielding chemical reaction between silyl enol ethers and peroxy acids to give the corresponding α-hydroxy carbonyl product	i	1	Go
Sandmeyer bromination	An aromatic substitution reaction where an aryl diazonium salt reacts with a copper(I) bromide to form an aromatic bromide.	i	705	Go
Sandmeyer chlorination	An aromatic substitution reaction where an aryl diazonium salt reacts with a copper(I) chloride to form an aromatic chloride.	i	360	Go
Sandmeyer fluorination	An aromatic substitution reaction where an aryl diazonium salt reacts with a copper(I) fluoride to form an aromatic fluoride.	i	2	Go
Sandmeyer iodination	An aromatic substitution reaction where an aryl diazonium salt reacts with a copper(I) iodide to form an aromatic iodide.	i	13	Go
Sandmeyer reaction	An aromatic substitution reaction where an aryl diazonium salt reacts with a copper(I) halide or pseudohalide to form an aromatic halide or pseudohalide.	i	1	Go
Sandmeyer reaction, copper free	An aromatic substitution reaction where an aryl diazonium salt or amine reacts with a halogen source to form an aromatic halide or pseudohalide.	i	135	Go
Schmidt rearrangement, carboxylic acid	The reaction of a carboxylic acid with hydrazoic acid to give the lower homologue amine, with the loss of the terminal carbon atom.	i	147	Go
Schotten-Baumann reaction	The coupling of an alcohol or amine with an acyl chloride to give an ester or amide. A two-phase solvent system is often used, to enable the acid generated during the reaction to be neutralised by the aqueous base, while the starting materials and products remain in the organic phase.	i	22548	Go
secondary alcohol oxidation to ketone	An oxidation process where a secondary alcohol is transformed into a ketone.	i	553	Go
secondary, non-terminal alkene oxidation to aldehydes	An alkene oxidation process where the reactant is a secondary alkene and the products are the corresponding aldehydes. This can be achieved with warm, acidic potassium permanganate.	i	117	Go
Selenium incorporating reaction	Any reaction introducing an organoselenium bond into a substrate	i	7	Go
Selenoxide elimination	is a method for the chemical synthesis of alkenes from selenoxides.Source: Wikipedia	i	22	Go
semipinacol rearrangement	A rearrangement of a 1,2-diol	i	1	Go
Seyferth-Gilbert aldehyde homologation	Reaction of an aldehyde with a dimethyl diazomethyl phosphonate under basic conditions to yield a terminal alkyne.	i	2	Go
Seyferth-Gilbert homologation	Reaction of a carbonyl compound with a dimethyl diazomethyl phosphonate under basic conditions to yield an alkyne.	i	61	Go
Seyferth-Gilbert-Bestmann homologation	Seyferth-Gilbert aldehyde homologation where the Seyferth-Gilbert reagent is generated in situ by reaction with methanol and potassium carbonate.	i	7	Go
Shapiro reaction	The reaction of a tosylhydrazone of an aldehyde or ketone with an alkyllithium or Grignard reagent to give an olefin.	i	2	Go
Sharpless asymmetric dihydroxylation	The dihydroxylation of an alkene to give an alpha,beta-diol, with control of absolute stereochemistry at the two new stereocentres. The oxidising agent is osmium tetroxide, which is used catalytically with a stoichiometric oxidant and a chiral ligand. The reagents are available commercially as AD-mix.	i	59	Go
Sharpless asymmetric epoxidation	The epoxidation of an allylic alcohol to give a beta,gamma-epoxy alcohol, with control of absolute stereochemistry at the two new stereocentres. The oxidising agent is tert-butyl hydroperoxide, and the catalyst is a complex of titanium salt and optically active diethyl tartrate.	i	2	Go
silyl protection	A hydroxyl group protection where the hydroxyl oxygen atom is protected by formation of a silyl ether.	i	4532	Go
Simmons-Smith reaction	A ring formation reaction where an alkene reacts with a dihalomethane in the presence of a metal atom or metal complexes to form a cyclopropane. The traditional reaction uses a zinc-copper couple and diiodomethane.	i	2	Go
Sonogashira coupling	A carbon-carbon coupling reaction where a terminal alkyne reacts with an aryl halide to give an aryl alkyne. It is catalysed by palladium.	i	1	Go
Staudinger reaction	A joining of an organic azide and a tertiary phosphine to give a phosphazo compound.	i	46	Go
Staudinger synthesis	Reaction of an imine and an ketene to form a beta-lactam via a [2+2] cycloaddition. Source: Wikipedia	i	1	Go
Still-Gennari modification	A Horner-Wadsworth-Emmons reaction that uses phosphonates with electron-withdrawing groups and dissociating conditions to produce predominantly Z-olefins.	i	12	Go
Stille coupling	A carbon-carbon coupling reaction where a stannane (organotin cmp.) reacts with an organohalide or organotriflate.	i	2903	Go
Strecker reaction	An addition reaction between a carbonyl compound, an inorganic cyanide and an ammonium salt, followed by hydrolysis, to give an alpha-amino carboxylic acid.	i	116	Go
Sulfonamide synthesis	Formation of an sulfonamide from an amine and a sulfonyl chloride. Protection reactions excluded	i	9812	Go
Sulfur dioxide extrusion	any reaction in which sulfur dioxide is extruded from a ring system (March 7-51)	i	6	Go
Suzuki-Miyaura coupling	The coupling of two unsaturated halides, triflates or sulfonates with a boron-based reagent, catalysed by a palladium(0) complex.	i	426	Go
Swern oxidation	The oxidation of a primary alcohol or secondary alcohol to an aldehyde or ketone respectively. Does not work with allylic or benzylic alcohols.	i	997	Go
tert-butyl ester deprotection	A deprotection reaction where the reactant is a tert-butyl ester and the product is a carboxylic acid.	i	6973	Go
Thiazole synthesis	Any thiazole ring form reaction.	i	1683	Go
thioketone compound to imine conversion	A functional group modification where a thioketone compound is converted to an imine. With an α-carbonyl proton present the reaction product is an enamine.	i	237	Go
Thiophene synthesis	Any thiophene ring forming reaction	i	3	Go
Transesterification	Alcoholysis reaction of an ester. Equilibrium reaction acid / base catalyzed (March 0-25)	i	77	Go
Transfer hydrogenation	Transfer hydrogenation is the addition of hydrogen to a molecule from a source other than gaseous hydrogen	i	51	Go
Trifluoromethylation	Any organic reaction that introduces a trifluoromethyl group in an organic compound. Source: Wikipedia	i	643	Go
triflyloxy Heck reaction	A Heck reaction where an organotriflate couples to a terminal olefin to produce an internal olefin, catalysed by palladium.	i	21	Go
triflyloxy Sonogashira coupling	A Sonogashira coupling where the role of the halide is played by a triflyloxy group.	i	93	Go
triflyloxy Suzuki coupling	A Suzuki coupling where the rule of the halide is played by a triflyloxy group.	i	1519	Go
Tsuji-Trost reaction	A carbon-carbon coupling reaction in which a nucleophile reacts with an allyl acetate, allyl halide, allyl carbonate, allyl carbamate, allyl phosphate, allyl sulfone or allyl nitro compound to give an allyl compound. The reaction is catalsed by Pd(0).	i	1	Go
Ugi reaction	Reaction of a ketone or aldehyde, amine, an isocyanide and carboxylic acid to form a bisamide.	i	1	Go
Ullmann reaction	A carbon-carbon homocoupling reaction of an aryl halide mediated by copper.	i	406	Go
Upjohn dihydroxylation	an organic reaction which converts an alkene to a cis vicinal diol with N-methylmorpholine N-oxide as stoichiometric re-oxidant for osmium tetroxide.	i	578	Go
Urea synthesis	Synthesis of ureas and thioureas by addition of an amine to a isocyanate or isothiocyanate. (March 6-17)	i	2062	Go
Van Leusen reaction	is the reaction of a ketone with TosMIC leading to the formation of a nitrile. (Source Wikipedia)	i	66	Go
Vilsmeier-Haack reaction	A formylation of an activated arene with a disubstituted formamide to give an arenecarbaldehyde.	i	24	Go
Wagner–Meerwein rearrangement	A Wagner–Meerwein rearrangement is a class of carbocation 1,2-rearrangement reactions in which a hydrogen, alkyl or aryl group migrates from one carbon to a neighboring carbon	i	1	Go
Weinreb ketone synthesis	The conversion of an acid chloride with N,O-dimethylhydroxylamine to form a Weinreb–Nahm amide, and subsequent treatment with an organometallic reagent such as a Grignard reagent or organolithium reagent to form a ketone or aldehyde. (Source Wikipedia)	i	606	Go
Williamson ether synthesis	The reaction between an alkyl halide or alkyl sulfate and a metal alkoxide to give an ether.	i	23778	Go
Wittig homologization	A wittig reaction of an aldehyde with a specific phosphorane to extend a chain by one methylene group	i	2	Go
Wittig reaction	A carbon-carbon coupling reaction where a carbonyl compound reacts with a phosphonium ylide to give an alkene.	i	2918	Go
Wolff-Kishner reduction	The reduction of an aldehyde or ketone to the corresponding methylene compound, using hydrazine hydrate and a base.	i	252	Go
[1,5]-sigmatropic rearrangement	A [1,5] sigma tropic shift involves the shift of 1 substituent (hydride, alkyl, or aryl) down 5 atoms of a π system. Source: Wikipedia	i	1	Go
[2+2+1] cycloaddition	A cycloaddition in which two participants contribute two electrons and the other participant contributes one electron to the transformation of reactants to products.	i	1	Go
[2+2] cycloaddition	A cycloaddition in which each participant contributes two electrons to the transformation of reactants to products.	i	1	Go
[3+2] cycloaddition	A cycloaddition in which one participant contributes three electrons and the other participant contributes two electrons to the transformation of reactants to products.	i	1	Go
[5+2+1] cycloaddition	A cycloaddition in which one participant contributes five electrons and the other participant contributes two electrons to the transformation of reactants to products.	i	1	Go
α,α-dihalogenation of carbonyl compounds	Dihalogenation of ketones at the alpha position forming a dihalo methylene group	i	494	Go

classification based on Ontobee name reaction ontology