As reported in The Angewandte, a new nickel catalyst is proposed for coupling reactions, specifically Suzuki reactions (F. Flecken et al. DOI). This type of reaction is heavily dominated by palladium and nickel elbowing it's way in is certainly newsworthy. In the Chemical Reaction Database palladium has 107K entries with reaction types mostly coupling reactions and reductions whereas nickel has just 6K mentions all of them reductions, the number of nickel catalyzed coupling reactions is just 40 with bis(COD)nickel, dichloro(dimethoxyethane)nickel and nickel iodide signing of for the Suzuki couplings and in addition [dppp]nickel chloride and bis(triphenylphosphine)nickel dichloride for Kumada couplings.

The new catalyst was synthesized from 1,1,2,2-Tetraphenyldiphosphane 1-oxide and Tetrakis(acetonitrile)nickel(II) tetrafluoroborate for which the authors propose an unusual reaction mechanism: the phosphine (Ph)2P=OP(Ph)2 oxidizes nickel(II) to nickel(0) leaving tetraphenyl diphosphine dioxide (Ph)2P=OP=O(Ph)2 which would quietly exit the stage if it was not for the tetraborate anions to fluorinate it and then re-assemble the debris to ligands.

And what would make the catalyst stand out from the crowd? The article explains that in contrast to palladium, nickel in general is cheaper, it has more oxidation states and is more reactive in oxidative addition. More specific, this catalyst, despite being more reactive in oxidation is air- and moisture stable. The catalyst was found to perform well in a typical Suzuki reaction with 60% conversion at 100 degrees. A quantitive yield was obtained in a co-ligand system with dppf and under UV light.