Synthesis of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions
作者:Milovan Stojanović、Rade Marković、Erich Kleinpeter、Marija Baranac-Stojanović
DOI:10.1039/c1ob06451g
日期:——
6)-membered acetal derivative and the tricyclic system with an eight-membered central ring were obtained from the substrates containing O and S nucleophilic moieties, respectively. The reaction outcome and stereochemistry are rationalized using quantum chemical calculations at B3LYP/6-31G(d) level. The exclusive cis-stereoselectivity in the formation of (5,6)- and (5,5)-membered systems results from thermodynamic
的合成 噻唑烷已经研究和讨论了通过掺入基于杂原子的亲核试剂的乙烯基N-酰亚胺离子的外模环化形成的稠合杂环。对于所有尝试的亲核试剂(O,S和N),(5,6)元体系的形成都是可行的,而五元环的封闭仅限于O和S亲核试剂。四元环的关闭失败。取而代之的是,分别从包含O和S亲核部分的底物获得双环(5,6)元乙缩醛衍生物和具有八元中心环的三环系统。反应的结果和立体化学使用B3LYP / 6-31G(d)水平的量子化学计算进行了合理化。独有的顺式(5,6)-和(5,5)-元系统形成中的-立体选择性是由热力学控制引起的,而八元环的形成是动力学控制的。