Chemoselective and stereoselective synthesis of gem-difluoro-β-aminoesters or gem-difluoro-β-lactams from ethylbromodifluoroacetate and imines during Reformatsky reaction
摘要:
The chemoselective and stereoselective synthesis of gem-difluoro-beta-amiinoesters or genz-difluoro-beta-lactams was investigated from ethylbromodifluoroacetate and imines during Reformatsky reaction. Influence of various reaction parameters, such as nature of the amine part, nature of the chiral auxiliary, was evaluated. High levels of stereoselectivity (up to 98%) were obtained for gem-difluoro-beta-aminoesters and gem-difluoro-beta-lactams using either (R)-phenylglycinol or (R)-methoxyphenylglycinol. (c) 2007 Elsevier Ltd. All rights reserved.