Strategic Vinyl Sulfone Nucleophile β-Substitution Significantly Impacts Selectivity in Vinylogous Darzens and Aza-Darzens Reactions
Strategic Vinyl Sulfone Nucleophile β-Substitution Significantly Impacts Selectivity in Vinylogous Darzens and Aza-Darzens Reactions
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DOI：
10.1021/acs.orglett.0c02448
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发表时间：
2020-09-04
期刊：
影响因子：
5.2
通讯作者：
Njardarson, Jon T.
中科院分区：
文献类型：
--
作者：
Delost, Michael D.;Njardarson, Jon T.
报道了苯并噻吩型1，1-二氧化氮的Vinylogy-Darzens反应和aza-Darzens反应。这些新的[2+1]环化反应在温和的反应条件下进行，具有伽马选择性，选择性地提供反式环氧化物，并有利于反式氮杂环丙烷。这些反应是碱相关的，其中KOtBu和Cs2CO3分别是醛和亚胺环化的最佳选择。苯并噻吩亲核试剂与其非环亲核试剂的比较显示，在醛的情况下性能更好，而结果因使用的磺胺亚胺而不同。
Vinylogous Darzens and aza-Darzens reactions employing a benzothiophene 1,1-dioxide nucleophile are reported. These new [2 + 1] annulation reactions, which proceed under mild reaction conditions, are gamma-selective, affording trans-epoxides selectively and favoring trans-aziridines. The reactions are base-dependent, with KOtBu and Cs2CO3 being optimal for aldehyde and imine annulations, respectively. Comparison of the benzothiophene nucleophile to its acyclic counterpart reveals superior performance in the case of aldehydes, while the outcome varies depending on the sulfonamide imine used.