A NICKEL-CARBENE COMPLEX AS AN INTERMEDIATE IN THE POLYMERIZATION OF ISOCYANIDES

Article abstract of DOI:10.1002/recl.19881070314

An intermediate in the polymerization of isocyanides, catalysed by nickel(II), has been isolated and characterized.The polymerazation starts by nucleophilic attack of (S)-(-)-(1-phenylethyl)amine on the terminal carbon atom of a coordinated isocyanide of tetrakis(tert-butyl isocyanide)nickel(II) perchlorate.The resulting intermediate was isolated and shownto be a nickel-carbene complex: Ni(C=N-t-C4H9)3NH-t-C4H9>(ClO4)2>.In solution, the carbene complex appears to have three conformations.The effect of these conformations on the enantioselective polymerazation of isocyanides is discussed.