Dual Nickel/Photoredox‐Catalyzed Site‐Selective Cross‐Coupling of 1,2‐Bis‐Boronic Esters Enabled by 1,2‐Boron Shifts

Site-selective transition-metal-catalyzed mono-deboronative cross-couplings of 1,2-bis-boronic esters are valuable methods for the synthesis functionalized organoboron compounds. However, such limited to reaction sterically less hindered primary boronic ester. Herein, we report a nickel/photoredox-catalyzed arylation that is selective coupling more secondary/tertiary position. This achieved by taking advantage 1,2-boron shift β-boryl radicals thermodynamically favored radicals, which subsequently intercepted nickel catalyst enable arylation. The mild conditions amenable broad range aryl halides give β-aryl ester products in good yields and with high regioselectivity. method also allows stereodivergent cyclic cis-1,2-bis-boronic trans-substituted products.