The conformational bias of aryl, arylsulfonyl geminally substituted tertiary carbon centers: applications in substrate-based stereocontrol
作者:Jeremy P. Scott、Peter R. Mullens、Sarah E. Brewer、Karel M. J. Brands、Jennifer R. Chilenski、Antony J. Davies、Andrew D. Gibb、David R. Lieberman、Steven F. Oliver、Ulf-H. Dolling
DOI:10.1039/b601647b
日期:——
Intramolecular nitrile oxide–olefin cycloaddition to form hexahydrobenzisoxazole 14, which engenders a phenylsulfonyl, 2,5-difluorophenyl geminally substituted carbon substructure, proceeds with up to 99% ds. A rationalization of the high level of substrate-based stereo-induction observed in this and related ketone and acrylonitrile metallohydride reductions, supported by single crystal X-ray crystallography, is presented.
分子内氧化腈-烯烃环加成形成六氢苯并异恶唑 14,产生苯磺酰基、2,5-二氟苯基孪位取代的碳亚结构,收率高达 99%。提出了在单晶 X 射线晶体学的支持下,在该反应以及相关的酮和丙烯腈金属氢化物还原中观察到的高水平基于底物的立体诱导的合理化。