Noninnocent Deep Eutectic Solvents Enable Selective, Sustainable Nickel‐Catalyzed Cross‐Electrophile Couplings to Diarylmethanes

We report the first sustainable nickel‐catalyzed cross‐electrophile coupling (XEC) between aryl iodides and benzyl chlorides conducted in a deep eutectic solvent (DES), choline chloride/urea (1:2 mol mol ^–1 ), replacing the hazardous amide solvents traditionally used in this transformation. The reaction proceeds efficiently under mild (50 °C), aerobic, and heterogeneous conditions, using zinc as the terminal reductant, (dtbbpy)NiBr ₂ (2 mol%) as catalyst, and MePh ₃ PBr (10 mol%) as additive, delivering a broad range of diarylmethanes in up to 95% yield with wide functional‐group tolerance and gram‐scale applicability within 3 h. Mechanistic and electrochemical studies support a radical/polar crossover pathway in which benzyl radicals, generated off‐cycle from benzyl chlorides, are selectively funneled into productive cross‐coupling through a predominantly Ni(I)/Ni(II)/Ni(III) catalytic manifold rather than diverted into homodimerization. The phosphonium salt appears to modulate nickel speciation, stabilize reduced Ni intermediates, and promote interfacial electron transfer between insoluble substrates and the fraction of nickel catalyst dissolved in the DES. The halide‐rich DES environment likely enhances the reducing power of Zn through Zn ²⁺ chloride complexation and improved zinc surface activation. Overall, this study establishes DESs as noninnocent media for XEC, providing a sustainable platform beyond conventional volatile organic compound (VOC)‐based solvent systems.