1203477-60-4Relevant articles and documents
Synthesis of electron-rich CNN-pincer complexes, with N-heterocyclic carbene and (S)-proline moieties and application to asymmetric hydrogenation
Boronat, Merce,Corma, Avelino,Gonzalez-Arellano, Camino,Iglesias, Marta,Sanchez, Felix
experimental part, p. 134 - 141 (2010/03/03)
New chiral CNN-pincer-type gold, palladium, and rhodium complexes containing N-heterocyclic carbene substituent and (S)-N-tert-butyl- methylpyrrolidine-2-carboxamide as chiral auxiliary have been synthesized and studied for asymmetric hydrogenation. The complexes were prepared by the silver carbene transfer route from the respective silver complex. The reaction with [RhCl(cod)]2 (cod = cycloocta-l,5-diene), PdCl2(CH 3CN)2, or K[AuCl4] affords the corresponding cationic [Rh(cod)(ligand)]Cl, [PdCl(ligand)]Cl, and [AuCl(ligand)]Cl2 complexes in which the ligand functions effectively in a CNN coordination mode. The complexes catalyze the enantioselective hydrogenation of prochiral alkenes. Enantioselectivity is very sensitive to the NHC N-substituent, resulting in a useful switch in the predominant enantiomer.
