Ring-opening of epoxides furnishing either linear or branched products belongs to the group of classic transformations in organic synthesis. However, the regioselective cross-electrophile coupling of aryl epoxides with aryl halides still represents a key challenge. Herein, we report that the vitamin B 12 /Ni dual-catalytic system allows for the selective synthesis of linear products under blue-light irradiation, thus complementing methodologies that give access to branched alcohols. Experimental and theoretical studies corroborate the proposed mechanism involving alkylcobalamin as an intermediate in this reaction.

Oxetanes are valuable building blocks due to their well-explored propensity to undergo ring-opening reactions with nucleophiles. However, their application as precursors of radical species is still elusive. Herein, we present a bioinspired cobalt-catalysis-based strategy to access unprecedented modes of radical reactivity via oxetane ring-opening. This powerful approach gives access to nucleophilic radicals that engage in reactions with SOMOphiles and low-valent transition metals. Importantly, the regioselectivity of these processes complements known methodologies.

Co complex – Cby(OMe)7 ‐ enables consecutive generation of alkyl and acyl radicals from adequately designed carboxylic acids possessing a halogen atom in theirs structures. Mechanistic studies reveal that alkyl corrins forms at much higher rate than the respective acyl derivatives enabling selective reactions with activated olefins.