Ir-Catalysed Asymmetric Hydrogenation:Ligands,Substrates and Mechanism

摘要

Relatively air and moisture tolerant cationic iridium complexes,with chiral non-racemic N,P-ligands and weakly coordinating counter ions,are efficient catalysts in the asymmetric hydrogenation of olefins.Un-functionalised olefins are particularly difficult substrates because,in general,a polar group adjacent to the alkene bond is required for high catalytic activity and enantioselectivity.The applicability towards a variety of substrates and choice of ligands reported thus far in the literature,as well as the mechanism,selectivity issues and the importance of the anion are also discussed.