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

A protocol involving facile sequential C(sp(3))-H and C(sp(2))-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(sp(3))-H and C(sp(2))-H bond activation under mild reaction conditions.