A new tetratertiary phosphine ligand and its use in Pd-catalyzed allylic substitution

A new tetraphosphine, the cis-cis-cis-1,2,3,4-tetrakis(diphenylphosphinomet hyl)cyclopentane(Tedicyp) 1 has been synthesized, characterized, and used i n Pd-catalyzed allylic substitutions. The Tedicyp was easily prepared in se ven steps from the commercially available himic anhydride. The structure of the complex Tedicyp-borane was determined by X-ray analysis. The tetraphos phine in combination with [Pd(eta (3)-C3H5)Cl](2) affords a very efficient catalyst for allylic substitution of several allylic acetates. Under mild c onditions, very high turnover numbers and turnover frequencies have been ob tained.