4,5-二氢-1 H,3 H-环丙[ f ]茚满-4-醇(1)和二乙基4,5-二氢-1 H,3 H-环丙[ f ]-茚满-4,描述了从二烯4开始的4-二羧酸酯(26)。环戊烯环通过丙二酸二乙酯与二溴化物21的缩合而构成。的关键步骤中的合成1由以双重库尔提斯降解22,随后还原羰基和芳构化的。异构体的骨架31合成通过丁二烯环化加成到环戊-4-烯-1,3-二酮(7)上,缩酮化后将二氯卡宾加成到加合物27中。通过碱诱导的几种适当取代的前体的消除尝试合成二氢环丙基[ f ]茚(2)的尝试失败了。
4,5-二氢-1 H,3 H-环丙[ f ]茚满-4-醇(1)和二乙基4,5-二氢-1 H,3 H-环丙[ f ]-茚满-4,描述了从二烯4开始的4-二羧酸酯(26)。环戊烯环通过丙二酸二乙酯与二溴化物21的缩合而构成。的关键步骤中的合成1由以双重库尔提斯降解22,随后还原羰基和芳构化的。异构体的骨架31合成通过丁二烯环化加成到环戊-4-烯-1,3-二酮(7)上,缩酮化后将二氯卡宾加成到加合物27中。通过碱诱导的几种适当取代的前体的消除尝试合成二氢环丙基[ f ]茚(2)的尝试失败了。
Cu(II)-catalyzed highly enantioselective intramolecular cyclization of N-alkenylureas was developed for the concise assembly of chiral vicinal diamino bicyclic heterocycles. Facile removal of carbonyl group of the carbamido moiety allowed for ready access to enantioenriched cyclic vicinal diamines.
Enantioselective Henry reaction catalyzed by a C2-symmetric bis(oxazoline)–Cu(OAc)2·H2O complex
作者:Sandeep K. Ginotra、Vinod K. Singh
DOI:10.1039/b714153j
日期:——
A C(2)-symmetric diethyl (i)Pr-bis(oxazoline)-Cu(OAc)(2).H(2)O was found to be an efficient catalyst for catalyzing an enantioselective Henry reaction between nitromethane and various aldehydes to provide beta-hydroxy nitroalkanes with high chemical yields (up to 95%) and enantiomeric excesses (up to 97%).
Cu(I)/Chiral Bisoxazoline-Catalyzed Enantioselective Sommelet–Hauser Rearrangement of Sulfonium Ylides
作者:Shu-Sen Li、Jianbo Wang
DOI:10.1021/acs.joc.0c01590
日期:2020.10.2
asymmetric thia-Sommelet–Hauser rearrangement of sulfonium ylides remains a great challenge due to its multistep reaction mechanism involving metal carbene formation, proton transfer, and [2,3]-sigmatropic rearrangement. In particular, the key problem of such reactions is the differentiation of the enantiotopic lone pair electrons of sulfur, which generates the sulfonium ylide intermediate bearing chirality