THE CHEMISTRY OF MER-(ME3P)3IR(H)(2-FURYL)(CL) - PREFERENTIAL REACTION OF AN ALKYNE WITH AN IR-C BOND IN THE PRESENCE OF AN IR-H BOND

The complex mer-(Me3P)3Ir(H)(2-furyl)(Cl), formed by oxidative additio n of a C-H bond of furan to [Ir(COD)(PMe3)3]Cl, reacts with tert-butyl acetylene via insertion of the alkyne into the Ir-C bond even in the p resence of the Ir-H bond. The product of this reaction was characteriz ed crystallographically and shown to be a vinyliridium hydride complex with the furyl group attached to the alpha-carbon of the vinyl ligand . Another unusual feature of this complex is the presence of an agosti c interaction between the iridium and the tertbutyl group on the vinyl ligand. A mechanism for the formation of this product is proposed.