Zn(OTf)<sub>2</sub>-Catalyzed Cyclization of Proparyl Alcohols with Anilines, Phenols, and Amides for Synthesis of Indoles, Benzofurans, and Oxazoles through Different Annulation Mechanisms
作者:Manyam Praveen Kumar、Rai-Shung Liu
DOI:10.1021/jo0606711
日期:2006.6.1
intermediates A and C were isolated as reaction intermediates. The 1,2-nitrogen shift in the formation of indole is catalyzed by Zn(OTf)2, and its mechanism has been elucidated. This catalytic cyclization is also applicable to the synthesis of oxazoles through the cyclization of propargyl alcohols and amides without a 1,2-nitrogen shift.
锌(OTF)2(10摩尔%)催化的炔丙基醇的环化用PhXH(X = O,NH)在热甲苯(100 ο无添加剂C)和,得到吲哚和苯并呋喃产品具有不同的结构。在这样的转化中,分离出α-羰基中间体A和C作为反应中间体。Zn(OTf)2催化了吲哚形成过程中的1,2-氮转移,并阐明了其机理。该催化环化还可用于通过炔丙基醇和酰胺的环化而合成1,2-二氮杂苯而没有1,2-氮转移的恶唑类化合物。