The reactions of alkyltrimethylphosphinenickel complexes with isocyanides and alkynes

Article abstract of DOI:10.1016/0022-328X(87)85104-5

t-Butylisocyanide reacts with NiRCl(PMe3)2 (R=CH3, Ia; R=CH2SiMe3, Ib) to give, successively, the products of mono- and di-insertion into the nickel-carbon bonds; with more than two equivalents of isocyanide, trimethylphosphine ligands are displaced.In contrast to related palladium reactions, cyclohexyl isocyanide gives mono-insertion products only, while benzyl isocyanide is polymerised.The reactions of diphenylacetylene with Ia and Ib in methanol give (Z)-vinylnickel complexes, trans-NiCl(PMe3)2, while from reaction in diethyl ether a precursor complex can be isolated.On heating the (Z)-vinyl complexes come into thermodynamic equilibrium with their (E)-isomers.The vinyl complexes are stereochemically rigid and resistant to further insertion.