Formation of bridging alkene and conjugated dialkenes exclusively generated from alkynes on the [3,3′-Co(1,2-C2B9H11)2]_ platform.: The unique hydroboration role of [3,3′-Co(1,2-C2B9H11)2]-_

The unprecedented metal-mediated transformation of an alkyne into a B,B′ bridging alkene is reported. Also, the unprecedented synthesis of a conjugated dialkene derivative of [3,3′-Co(1,2-C2B9H11)2]- generated only from an alkyne, contrary to the usual case where an alkyne and an alkene are needed, is described. This has been possible through the singular capacity of a B?H to produce hydroboration. Copyright © 2003 American Chemical Society.