Metal-free ring expansion of indoles with nitroalkenes: a simple, modular approach to 3-substituted 2-quinolones
作者:Alexander V. Aksenov、Alexander N. Smirnov、Nicolai A. Aksenov、Inna V. Aksenova、Jonathon P. Matheny、Michael Rubin
DOI:10.1039/c4ra14406f
日期:——
3-Substituted 2-quinolones are obtained via a novel metal-free transannulation reaction of 2-nitroolefins with 2-substituted indoles in polyphosphoric acid. This acid-mediated cascade transformation operates via the ANRORC (Addition of Nucleophile, Ring Opening, and Ring Closure) mechanism and can be used in combination with the Fisher indole synthesis to offer a practical three-component hetero-annulation
3-取代的2-喹诺酮是通过2-硝基烯烃与2-取代的吲哚在多磷酸中的新型无金属环转移反应获得的。这种酸介导的级联转化通过ANRORC(亲核试剂的添加,开环和闭环)机理进行操作,可以与Fisher吲哚合成结合使用,以提供一种实用的三组分杂环化方法从芳基肼,2-硝基烯烃和苯乙酮。还证明了该化学方法的另一种选择,该方法采用了富电子芳烃和戊烯与1-(2-吲哚基)-2-硝基烯烃的烷基化反应。