Remarkable differences in catalyst activity and selectivity for the production of methyl propanoate versus CO-ethylene copolymer by a series of palladium complexes of related C4-bridged diphosphines

Academic Article

Abstract

  • The C4-bridged diphosphines cis- and £ra7zs-l,2-bis(diphenylphosphinomethyl)cyclohexane (cis, la; trans, Ib) and e;zrfo,e7zrfo-2,3-bis(diphenylphosphinomethyl)norbornane and exo,enrfo-2,3-bis(diphenylphosphinomethyl)norbornane (endo,endo, le; exo,endo, Id) and their corresponding palladium complexes [(P-P)PdCl2] (2a-d), [(P-P)Pd(OAc)2] (3a-d), and [(P-P)PdMeCl] (P-P = la, 4a; P-P = le, 4c) have been prepared and characterized. Singlecrystal X-ray analysis of 2a reveals that la forms a seven-membered chelate ring with the ci's-disubstituted cyclohexyl ring in the expected chair conformation. Variable-temperature 31P{1H} NMR studies of 2a have revealed a dynamic process that interchanges stereoisomers via conformational changes in the six-membered ring, often characteristic of c/s-disubstituted cyclohexane derivatives. © 2000 American Chemical Society.
  • Authors

    Author List

  • Knight JG; Doherty S; Harriman A
  • Start Page

  • 4957
  • End Page

  • 4967
  • Volume

  • 19
  • Issue

  • 24