New approach to the preparation of bicyclo octane derivatives via the enantioselective cascade reaction catalyzed by chiral diamine-Ni(OAc)(2) complex
Wenyi Li, Xiaodong Liu, Zhifeng Mao, Qiao Chen, Rui Wang
ORGANIC & BIOMOLECULAR CHEMISTRY | ROYAL SOC CHEMISTRY | Published : 2012
A highly efficient catalyst system assembled from enantiomerically pure diaminocyclohexane and Ni(OAc)(2) is, for the first time, used to catalyze the cascade Michael-Henry reaction of various diones and substituted nitroalkenes. A series of polyfunctionalized bicyclo[3.2.1]octane derivatives containing four stereogenic centers are prepared with excellent enantioselectivities (up to >99% ee) and diastereoselectivities (up to 50 : 1 dr) with high yields. In addition, via this chiral diamine-Ni(OAc)(2) catalyst system, the base-induced epimerization leading to the decrease of stereoselectivity can be prevented.
Awarded by NSFC of China
Awarded by Key National S & T Major Project and Major New Drugs Development of China
We are grateful for the grants from the NSFC of China (20932003 and 90813012), the Key National S & T Major Project and Major New Drugs Development of China (2012ZX09504-001-003) and Young Scholar of Distinction for Doctoral Candidate of Lanzhou University.