Asymmetric enamide hydrogenation in the synthesis of N-acetylcolchinol: a key intermediate for ZD6126
作者:Ian C. Lennon、James A. Ramsden、Catherine J. Brear、Simon D. Broady、James C. Muir
DOI:10.1016/j.tetlet.2007.04.090
日期:2007.6
A synthesis of N-acetylcolchinol, a keyintermediate in the synthesis of ZD6126, was developed. The enantiodifferentiating step required the catalytic asymmetric hydrogenation of an enamide. After screening a range of metal and ligand combinations it was found that (S,S)-iPr–FerroTANE Ru(methallyl)2 and [(S,S)-tBuFerroTANE Rh(COD)]BF4 gave both high enantioselectivity (>90% ee) and high catalyst utility