Synthesis of Racemic and Enantiomerically Pure ( R*,R*,R* )‐Tris(α‐methylbenzyl)phosphane − X‐ray Crystal Structures of the Phosphane Oxides and Borane Complexes

An asymmetric synthesis of C 3 ‐symmetric phosphane 1 has been achieved. Two of the α‐methylbenzyl groups were introduced as nucleophiles (using an α‐methylbenzyl Grignard reagent), and asymmetry was introduced by resolution using ( R )‐α‐methylbenzylamine. The final α‐methylbenzyl group was introduced as an electrophile (α‐methylbenzyl iodide) in a modestly selective reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)