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

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 center dot 3HF (1.0 equiv.), the fluorination of MCPs can be realized in the presence of 9-mesityl-10-methylacridinium perchlorate and Co(dmgH)(2)PyCl, affording fluorinated 4-aryl-1,2-dihy-dronaphthalene 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.

Automated summary

A new method for the direct single-electron oxidation of methylenecyclopropanes (MCPs) was reported, leading to the rapid construction of 4-aryl-1,2-dihydronaphthalene derivatives through merging visible light photoredox catalysis and cobalt catalysis. In MeCN with Et3N·3HF, fluorinated derivatives were obtained in moderate yields, while in MeCN/HFIP, good yields were achieved through a MHAT process.