Palladium-Catalyzed Functionalization of Indoles with 2-Acetoxymethyl-Substituted Electron-Deficient Alkenes
作者:Shengming Ma、Shichao Yu、Zhihua Peng、Hao Guo
DOI:10.1021/jo061546s
日期:2006.12.1
New functionalizations of indoles via palladium-catalyzed reaction of indoles and 2-acetoxymethyl-substituted electron-deficient alkenes are reported. It was found that for N-protected indoles the reaction proceeded smoothly in the presence of 5 mol % of Pd(acac)(2) and 10 mol % of PPh3 at 80 degrees C in HOAc, while for N-unprotected indoles, the reaction was carried out by using 5 mol % of Pd(dba)(2) or 2.5 mol % of Pd-2(dba)(3), CHCl3 with 10 mol % of 2,2'-bipyridine as the catalyst in toluene. This strategy allows the selective installation of electron-deficient olefin functionality at the 3-position of indoles, which might be difficult to obtain by other methods and can be further elaborated.