Insights into the beta-Sultam Ring Formation in the Sulfa-Staudinger Cycloadditions
Insights into the beta-Sultam Ring Formation in the Sulfa-Staudinger Cycloadditions
复制标题
深入了解磺胺-施陶丁格环加成反应中β-磺胺环的形成
DOI：
10.1021/jo5020933
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发表时间：
2014
影响因子：
3.6
通讯作者：
Xu Jiaxi
中科院分区：
文献类型：
--
作者：
Yang Zhanhui;Xu Jiaxi
亚胺与磺酰氯化物甚至直接亚砜反应生成β-磺胺，本文称之为磺胺- staudinger环加成。β-苏坦的形成遵循以2,3-噻唑丁二烯型两性离子中间体为关键中间体的磺化、去质子化和控制环闭合的逐步机制。环(Z)-亚胺只产生反式-β-磺胺，这表明线性(E)-亚胺产生的中间体直接经过控制环闭合以提供-β-磺胺。同时，它们的最小同分异构体通过控制环闭合导致反式β-sultams。
The reaction of imines with sulfonyl chlorides or even direct sulfenes to form β-sultams is herein named as sulfa-Staudinger cycloaddition. The β-sultam formation is proposed to follow a stepwise mechanism of sulfonylation, deprotonation, and conrotatory ring closure with 2,3-thiazabutadiene-type zwitterionic intermediates as key intermediates. Cyclic (Z)-imines give rise totrans-β-sultams exclusively, suggesting that the intermediates generated from linear (E)-imines undergo a conrotatory ring closure directly to affordcis-β-sultams. Meanwhile, their iminium isomers lead totrans-β-sultams via the conrotatory ring closure.