Synthesis of Enantiopure 1‐r‐Alkyl‐2‐c,5‐t‐Diphenylphospholanes and Phospholanium Salts through Direct Alkylation of Phospholane

Abstract Chiral enantiopure 1‐alkyl‐2,5‐diphenylphospholanium salts were obtained in one step through alkylation of phospholane with alkyl triflates. The resulting air‐stable phosphonium salts are electron‐rich trialkylphosphane precursor ligands for transition metals, and they offer a convenient route toward chiral quaternary phosphonium salts as phase‐transfer agents.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)