Chiral and achiral phosphine-phosphite ligands in Pd(II)-catalyzed alternating copolymerization of propene with CO

摘要

In addition to (R,S)-BINAPHOS, several related phosphine-phosphite ligands have been prepared and their use in Pd(II) catalyzed asymmetric alternating copolymerization of propene with carbon monoxide was examined. Small changes of the ligand substituents caused drastic changes of the stereo regularity of the product, which reveals that not only the electronic bias of (R,S)-BINAPHOS but also its steric demand is essential to produce completely isotactic copolymer from propene and CO in highly enantioselective fashion. (C) 1998 Elsevier Science Ltd. All rights reserved. [References: 26]