Electrochemical synthesis of dimeric platinum hydride species responsible for highly regioselective alkene hydroformylation

Abstract

PtL₂Cl₂ complexes (1)[L₂= diop, 2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane] have been used as catalyst precursors for alkene hydroformylation after electroreduction using a soluble tin or iron anode, followed by treatment with carbon monoxide–hydrogen; the remarkable regioselectivities for linear aldehyde formation (ca. 98% from hex-1-ene and 90% from styrene) are explained by the production of chelated, bridged platinum hydride cationic species [L₂Pt(H)(µ-L₂)Pt(H)L₂]²⁺, stabilized by the presence of a polar, highly dissociating solvent.