Photoinduced Nickel-Catalyzed Deaminative Cross-Electrophile Coupling for C(sp <sup>2</sup> )–C(sp <sup>3</sup> ) and C(sp <sup>3</sup> )–C(sp <sup>3</sup> ) Bond Formation
Tao Yang, Yi Wei, Ming Joo Koh
Abstract
The construction of C–C bonds through cross-coupling between two electrophiles in the absence of excess metallic reducing agents is a desirable objective in chemistry. Here, we show that N-alkylpyridinium salts can be efficiently merged with aryl or alkyl halides in an intermolecular fashion, affording products in up to 92% yield at ambient temperature. These reactions harness the ability of N-alkylpyridinium salts to form electron donor–acceptor complexes with Hantzsch esters, enabling photoinduced single-electron transfer and fragmentation to afford alkyl radicals that are subsequently trapped by a Ni-based catalytic species to promote C(sp2)–C(sp3) and C(sp3)–C(sp3) bond formation. The operationally simple protocol is applicable to site-selective cross-coupling and tolerates diverse functional groups, including those that are sensitive toward metal reductants.