Carbyne complexes featuring a metal-carbon triple bond LnMC–R are generally limited to those in which the substituent ‘R’ is an organic group (alkyl, aryl) and these are important catalysts for alkyne metathesis. Examples where the substituent is a main group heteroatom are scarce because conventional carbyne synthetic routes fail. We have developed routes for synthesis of a wide variety of carbyne complexes with unusual properties involving p-block element substituents starting from bromocarbyne complexes. These easily undergo nucleophilicsubstitution of the halide, either spontaneously or in palladium(0) mediated catalytic processes. Alternatively, facile lithium/halogen exchange with BuLi affords lithiocarbynes which in turn react with a range of electrophiles. Using these strategies we have isolated examples of carbyne ligands based on B, Si, Ge, Sn, Pb, P, As, Sb and Bi, e.g.,the tris(carbyne)silane H–Si(CMLn)3 shown.
