The hydropalladation of di- and tri-olefins to give η3-allylic palladium complexes

Abstract

Complexesofthetype[PdHL₂]⁺[IIa:L₂=1,2-bis(diphenylphosphino)ethaneandIIb;L₂= 1,2-bis(diphenylarsino)-ethane], generated in situ by treatment of [{[graphic omitted]Me₅)Cl}₂] with Ag[PF₆] and L₂, were treated with penta-1,3-diene, isoprene, cyclopentadiene, cyclohexa-1,3-diene, and cyclo-octa-1,3-diene to give the appropriate complexes of the type [Pd(all)L₂][PF₆](all = 1–3-η-allylic ligand) by addition of Pd–H to a double bond. Cycle-octa-1,5-diene underwent isomerisation to give the same 1–3-η-cycle-octenyl complex obtained from cycle-octa-l,3-diene. Cycloheptatriene gave a mixture of two η³-cycloheptadienyl complexes, while cyclo-dodeca-1.5.9.triene gave an η³-cyclododecadienyl complex. The complexes were characterised by ¹H, ¹³C, and ³¹P n.m.r. spectroscopy.