Visible-Light-Induced Regioselective Functionalization of alpha-Olefin: Development of One-Pot Photo-Synthesis of C-3-Substituted Dihydrobenzofurans

A method for the catalytic regioselective synthesis of C-3-substituted dihydrobenzofurans (DHBs) via [2 + 2] photo-cycloaddition of alkene and p-benzoquinone is developed. This method realizes the rapid synthesis of DHBs with readily available substrates and simple reaction conditions by using Lewis acid B(C6F5)(3) and Lewis base P(o-tol)(3) as a catalyst in combination with the classical Paterno-Bu'chi reaction.