Zhang Yan-Rong, He Lin, Wu Xu, Shao Pan-Lin, Ye Song
Beijing National Laboratory for Molecular Sciences, Laboratory of Chemical Biology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China.
Org Lett. 2008 Jan 17;10(2):277-80. doi: 10.1021/ol702759b. Epub 2007 Dec 18.
N-heterocyclic carbenes (NHCs) were demonstrated to be efficient catalysts for the Staudinger reaction of ketenes with N-tosyl, N-benzyloxycarbonyl, or N-tert-butoxycarbonyl imines. Chiral NHC 8b, conveniently prepared from L-pyroglutamic acid, catalyzed the reactions of arylalkylketenes with a variety of N-tert-butoxycarbonyl arylimines to give the corresponding cis-beta-lactams in good yields with good diastereoselectivities and excellent enantioselectivities (up to 99% ee). Two possible catalytic pathways, initiated by the addition of NHC to ketenes or imines, were discussed.
已证明N-杂环卡宾（NHCs）是烯酮与N-甲苯磺酰基、N-苄氧羰基或N-叔丁氧羰基亚胺发生施陶丁格反应的有效催化剂。由L-焦谷氨酸方便地制备的手性NHC 8b，催化芳基烷基烯酮与多种N-叔丁氧羰基芳基亚胺的反应，以良好的产率、良好的非对映选择性和优异的对映选择性（高达99%ee）得到相应的顺式β-内酰胺。讨论了由NHC加成到烯酮或亚胺引发的两种可能的催化途径。
