Palladium-catalyzed bisarylation of 3-alkylbenzofurans to 3-arylalkyl-2-arylbenzofurans on water: tandem C(sp3)–H and C(sp2)–H activation reactions of 3-alkylbenzofurans

Abstract

A protocol involving facile sequential C(sp³)–H and C(sp²)–H activation reactions of 3-alkylbenzofurans catalyzed by Pd(OAc)₂ in the presence of pivalic acid, silver salt, and tricyclohexylphosphine ‘on water’ was developed. Aryl iodides were used as substrates in a tandem bisarylation reaction to generate 3-arylalkyl-2-arylbenzofurans in moderate to high yields at room temperature. The reaction revealed in this study is a rare example of consecutive C(sp³)–H and C(sp²)–H bond activation under mild reaction conditions.