913963-65-2Relevant academic research and scientific papers
Chiral phosphino- and (phosphinooxy)-substituted N-heterocyclic carbene ligands and their application in indium-catalyzed asymmetric hydrogenation
Nanchen, Steve,Pfaltz, Andreas
, p. 1559 - 1573 (2007/10/03)
Enantiomerically pure iridium complexes with phosphino- and (phosphinooxy)-substituted N-heterocyclic carbene (NHC) ligands were synthesized. Investigation of their electronic properties showed a similar trans influence of the phosphino (or phosphinooxy) and the NHC units. The complexes were tested in iridium-catalyzed hydrogenation. While low conversions were observed with unfunctionalized olefins, the catalysts proved to be suitable for hydrogenation of the α,β-unsaturated ester 20, allylic alcohol 21, and imine 22. The enantioselectivities were, however, moderate.
