Synthesis of Bridged Heterocycles via Sequential 1,4- and 1,2-Addition Reactions to α,β-Unsaturated <i>N</i>-Acyliminium Ions: Mechanistic and Computational Studies
作者:Arife Yazici、Uta Wille、Stephen G. Pyne
DOI:10.1021/acs.joc.5b02572
日期:2016.2.19
be readily prepared from sequential 1,4- and 1,2-addition reactions of allyl and 3-substituted allylsilanes to indolizidine and quinolizidine α,β-unsaturated N-acyliminium ions. These reactions involve a novel N-assisted, transannular 1,5-hydride shift. Such a mechanism was supported by examining the reaction of a dideuterated indolizidine, α,β-unsaturated N-acyliminium ion precursor, which provided
从烯丙基和3-取代的烯丙基硅烷与吲哚并咪唑和喹oli嗪的α,β-不饱和N-酰基亚胺离子的1,4-和1,2-加成反应可以容易地制备新的三环桥接杂环系统。这些反应涉及一种新型的N辅助的跨环1,5-氢化物移位。通过研究双氘代吲哚并立唑,α,β-不饱和N-酰基亚胺离子前体的反应,并通过计算研究,支持了这种机制,该吲哚并咪唑提供了特定的双氘代三环桥联杂环产物。相反,相应的吡咯并[1,2- a]氮杂系统未提供相应的三环桥联杂环产物,仅给出了双烯丙基加合物,而更多取代的产物则产生了新的呋喃[3,2- d ]吡咯并[1,2- a ]氮杂产物。这样的杂环系统将有望成为用于新药物发现程序的新化合物文库的制备的有用支架。