Cobalt/Organophotoredox Dual-Catalysis-Enabled Cascade Cyclization of 1,6-Diynyl Esters via Formal 1,8-Acyloxy Migration

Abstract

Herein, we report a method for the generation of vinylallenes via cobalt/photoredox dual-catalysis-enabled formal 1,8-acyloxy migration of 1,6-diynyl esters. We demonstrated a 1,8-acyloxy migration/6π-electrocyclization cascade using (hetero)aryl-substituted 1,6-diynyl esters as substrates, leading to the formation of arenol derivatives. Several control experiments suggested that the β-oxygen elimination of a cobaltacyclopentadiene intermediate enabled formal 1,8-acyloxy migration to generate the vinylallene. We also applied this method to cascade cyclizations involving [2 + 2] or [4 + 2] cycloadditions to furnish various polycyclic molecules.

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