MORE HIGHLY MIXED, HIGHER ORDER CYANOCUPRATES "rt(2-thienyl)Cu(CN)Li2". EFFICIENT REAGENTS WHICH PROMOTE SELECTIVE LIGAND TRANSFER

Article abstract of DOI:10.1016/0022-328X(85)87388-5

The combination of an organolithium (R_TLi) and 2-lithiothiophene (2-thienyl) with CuCN forms a new reagents, "R_T(2-thienyl)Cu(CN)Li2".This species selectively transfers the R_T ligand in substitution reactions with epoxides and halides.In conjugate addition processes, the cuprate reacts with unhindered substrates, while β,β-disubstituted cases unexpectedly afford products resulting from 1,2-addition of the thiophene group.The prospects for use of these reagents in the synthesis of polyene macrolide antibiotics are discussed.