First enantiopure phosphapalladacycle with planar chirality. X-Ray study of the racemic dimer and (S-pl,SCSN)-diastereomer of its prolinate derivative

The first P,C-cyclopalladated complex with planar chirality was prepared by direct cyclopalladation of prochiral di-tert-butyl(ferrocenylmethyl)phosph ine. Resolution of the racemic dimer was achieved through separation of its diastereomeric (S)-prolinate derivatives. The palladacycle structure was c onfirmed by the H-1 NMR spectra of the dimer and its triphenylphosphine add uct and an X-ray diffraction study of the racemic dimeric complex. The abso lute configuration of the planar chirality was determined by an X-ray diffr action investigation of one of two diastereomers of the (S)-prolinate deriv ative. (C) 2000 Elsevier Science Ltd. All rights reserved.