Iron(III)-Catalyzed Cyclization of Alkynyl Aldehyde Acetals: Experimental and Computational Studies
作者:Tongyu Xu、Qin Yang、Dongpo Li、Jinhua Dong、Zhengkun Yu、Yuxue Li
DOI:10.1002/chem.201000686
日期:——
efficiently synthesized by FeCl3⋅6 H2O‐catalyzed intramolecularcyclization of alkynyl aldehyde acetals in acetone under mild conditions. An oxocarbonium species generated in situ is proposed to initiate the reaction, and the target products are formed via vinylogous carbenium cation and oxete intermediates according to DFT calculations. Intermolecular reactions of alkynes and aldehyde acetals were
的FeCl 3 ⋅ 6 H 2 O-和FeBr 3催化的环化反应的Prins /卤化炔醛缩醛已实现与乙酰氯或溴作为在二氯甲烷中,得到2-(1- halobenzylidene或烷叉)卤源的取代五元碳环和杂环,并且因此提供了一种用于乙烯℃的替代路线氯和C Br键的形成。五至八元环状烯酮得到有效利用的FeCl合成3 ⋅ 6 H 2在温和条件下O催化炔醛缩醛在丙酮中的分子内环化。提出了一种原位产生的氧碳鎓类物质来引发反应,并根据DFT计算,通过乙烯基碳正离子和氧杂环丁烷中间体形成目标产物。炔烃和醛缩醛的分子间反应也进行了研究用20-40摩尔%的FeCl 3 ⋅ 6 H 2 O类催化剂,和生产的α,β不饱和烯酮和氯化茚衍生物。本协议在碳,氧杂和氮杂环的合成中有应用。