Regioselective access to substituted oxindoles via rhodium-catalyzed carbene C–H insertion
作者:Delphine Gauthier、Robert H. Dodd、Philippe Dauban
DOI:10.1016/j.tet.2009.08.006
日期:2009.10
insertion of the resulting carbenes into an aromatic C–H bond gives access to substituted oxindoles. The reaction takes place with aromatic rings substituted by either electron-donating or -withdrawing groups at ortho, meta or para positions and the regioselectivity can be controlled by a substitution α to the diazo functionality. In the presence of an ester, the reaction leads to the formation of 2-silylo
铑催化的重氮酰胺分解,然后将所得的羧甲基插入芳族的C–H键中,从而获得了取代的羟吲哚。该反应由取代的芳环或者供电子性或吸电子在基团的邻位,间位或对位位置和区域选择性可通过替换α到重氮功能来控制。在存在酯的情况下,该反应以40-85%的收率形成2-甲硅烷氧基吲哚-3-羧酸酯,在间位取代的底物情况下,可观察到高达80%的区域选择性。这种选择性主要取决于空间因素和使用更大体积的N,N然后,二乙酰胺以2-91%的收率提供2-甲硅烷基氧吲哚-3-甲酰胺,具有完全的区域选择性。