Photoredox Ni-Catalyzed Selective Coupling of Organic Halides and Oxalates to Esters via Alkoxycarbonyl Radical Intermediates

A new approach for radical cross coupling of organic halides and oxalates toward esters has been developed via photoredox nickel dual catalysis. This method has been demonstrated for transformation of a wide range of aryl, heteroaryl, alkenyl, and alkyl bromides to various esters under mild conditions. Notably, fluoro-, chloro-, or iodo-substituents on the aryl bromides remain after the coupling reaction, which has been applied for the easy synthesis of drug molecules from simple aryl dihalides. Mechanistic studies indicate that an (alkoxycarbonyl)Ni(I) species might be generated via oxidation of Ni(0) species with an alkoxycarbonyl radical intermediate. Selective alkoxycarbonyl radical coupling over decarboxylative alkyl radical coupling is achieved here. [GRAPHICS] .

Automated summary

A new approach for the radical cross coupling of organic halides and oxalates toward esters has been developed using photoredox nickel dual catalysis. This method allows for the transformation of a wide range of bromides to esters under mild conditions, including aryl, heteroaryl, alkenyl, and alkyl bromides. The selective coupling of alkoxycarbonyl radicals over decarboxylative alkyl radicals has been achieved, making it a convenient method for the synthesis of drug molecules from simple aryl dihalides.