Rhodium catalysed diboration of unstrained internal alkenes and a new and general route to zwitterionic [L2Rh(η6-catBcat)] (cat = 1,2-O2C6H4) complexes†

Abstract

Reactions of [L₂Rh(acac)] (L = alkene or phosphine) with B₂cat₃ yield the zwitterionic complexes [L₂Rh(η⁶-catBcat)] and [(acac)Bcat] cleanly; [(dppm)Rh(η⁶-catBcat)], the X-ray structure of which is reported, is an excellent catalyst for the diboration of vinylarenes and unstrained internal alkenes cis- and trans-stilbene and trans-β-methylstyrene.