Visible light mediated synthesis of 4-aryl-1,2-dihydronaphthalene derivatives via single-electron oxidation or MHAT from methylenecyclopropanes

Abstract

We report a direct single-electron oxidation of methylenecyclopropanes (MCPs) for the rapid construction of 4-aryl-1,2-dihydronaphthalene derivatives by merging visible light photoredox catalysis and cobalt catalysis. In MeCN with Et₃N·3HF (1.0 equiv.), the fluorination of MCPs can be realized in the presence of 9-mesityl-10-methylacridinium perchlorate and Co(dmgH)₂PyCl, affording fluorinated 4-aryl-1,2-dihydronaphthalene derivatives in moderate yields. In MeCN/HFIP (7 : 3), 4-aryl-1,2-dihydronaphthalene derivatives were obtained in good yields through a MHAT process under similar conditions.