Synthesis and X‐Ray Crystal Structure of an Optically Pure Tripodal C3‐Symmetric Tritertiary Phosphine Bearing Chirality on Phosphorus

The preparation of the optically pure tritertiary phosphine (RRR)‐MeSi(CH2P(t‐Bu)Ph)3 (2) is reported. The route followed involves deprotonation of optically pure (R)‐P(BH3)Me(t‐Bu)PH (2) the reaction of the resulting carbanion with MeSiCl3, followed by removal with morpholine of the BH3‐protecting groups from the triertiary phosphine‐borane 3. The latter's X‐ray crystal structure and that of [Rh(NBD)((RRR)‐1]TOf)(4), are also rported. Furthermore, it is shown that the separation of the racemic phosphine‐borane 2 can be conveniently carried out using medium‐pressure liquid chromatgrapy with cellulose‐riacetate as a chiral stationary phase.