Asymmetric Hydrogenation of Pyridinium Salts with an Iridium Phosphole Catalyst
作者:Mingxin Chang、Yuhua Huang、Shaodong Liu、Yonggang Chen、Shane W. Krska、Ian W. Davies、Xumu Zhang
DOI:10.1002/anie.201406762
日期:2014.11.17
Iridium‐catalyzedasymmetrichydrogenation of N‐alkyl‐2‐alkylpyridinium salts provided 2‐aryl‐substituted piperidines with high levels of enantioselectivity. Simple benzyl and other alkyl groups successfully activated the challenging pyridine substrates toward hydrogenation. The use of the unusual chiral‐phosphole‐based MP2‐SEGPHOS was the key to the success of this approach which provides a versatile