Lewis acid promoted intramolecular (3 + 2) ‘cycloadditions’ of methyleneaziridines with alkene and alkyne acceptors
作者:Karen Griffin、Cyril Montagne、Cam Thuy Hoang、Guy J. Clarkson、Michael Shipman
DOI:10.1039/c1ob06578e
日期:——
2-Methyleneaziridines can be tethered to a variety of alkene or alkyne acceptors through the saturated carbon of the heterocyclic ring by application of a simple lithiation/alkylation sequence (8 examples, 31–59%). Treatment of the resultant alkene bearing substrates with BF3·OEt2 leads to cis-octahydrocyclopenta[c]pyrroles in which up to four contiguous stereocentres are created in a diastereocontrolled
可以通过应用简单的锂化/烷基化顺序(8个实例,31-59%),通过杂环的饱和碳将2-亚甲基氮丙啶束缚到各种烯烃或炔烃受体上。用BF 3 ·OEt 2处理所得的带有烯烃的底物导致顺式-八氢环戊基[c]吡咯,其中在还原后,以非对映控制的方式产生多达四个连续的立体中心。使用基于炔的底物,通过最初形成的双烯胺的快速互变异构化来制备2,4,5,6-四氢环戊[c]吡咯。这些(3 + 2)'环加成'逐步通过2-氨基烯丙基阳离子进行的证据。