Synthesis of Functionalized Indoles via Palladium-Catalyzed Cyclization of N-(2-allylphenyl) Benzamide: A Method for Synthesis of Indomethacin Precursor

摘要

We developed an efficient method for synthesis of substituted -benzoylindole via Pd(II)-catalyzed C–H functionalization of substituted -(2-allylphenyl)benzamide. The reaction showed a broad substrate scope (including -acetyl and -Ts substrates) and substituted indoles were obtained in good to excellent yields. The most distinctive feature of this method lies in the high selectivity for -benzoylindole over benzoxazine, and this is the first example of Pd(II)-catalyzed synthesis of substituted -benzoylindole. Notably, this new method was applied for the synthesis of key intermediate of indomethacin.