Phosphaferrocenes containing the chiral pinene-fused cyclopentadienyl ligand PCp

The chiral PCp-substituted phosphaferrocene 7 was prepared from the dimeric iron carbonyl complex [PCpFe(Co)(2)](2) (5) and t-butylphosphole (PCp=pine ne-fused cyclopentadienyl). In 7, the PCp ligand is coordinated to the iron atom via its exO-side as shown by X-ray crystallography. Formylation of th e sandwich complex 7 leads to a mixture of the diastereomeric aldehydes 10a ,b in an approximate ratio of 2:1. As a side-product of the synthesis of 7, the homoleptic ferrocene (PCp)(2)Fe (8) was obtained by a ring ligand tran sfer reaction. Complex 8 is formed as a single C-2-symmetrical isomer. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.