A Novel Approach to Ferrocenes with Planar Chirality

The 2‐metalation of enantiomerically pure (S)‐(2‐methoxy‐methylpyrrolidin‐1‐yl)ferrocene FcSMP (1) with BuLi proceeds with high diastereoselectivity (up to 98% de) to yield the Ph2P‐substituted ferrocene (S,Sp)‐2a after quenching with Ph2PCl. The SMP moiety was removed by heating of 2a at reflux in acetic anhydride to give planar chiral (Sp)‐2‐diphenylphosphanylferrocenylmethyl acetate (5). The diastereoisomer (S,Rp)‐2b was synthesized from 1 by intermediately blocking the primary metalation site with a Me3Si group which can be removed afterwards by treatment with KOtBu in DMSO. Compound 2a was treated with [(C3H5)PdCl]2 to give the complex [(C3H5)Pd·2a]PF6 (7·PF6). The structure of 7·PF6 was determined by a single‐crystal X‐ray diffraction study and showed 2a to act as a bidentate P,N‐chelate ligand.