02 May 2024 | Cheng-Long Ji, Hongliang Chen, Qi Gao, Jie Han, Weipeng Li & Jin Xie
This study reports a novel dinuclear gold-catalyzed divergent dechlorinative radical borylation of gem-dichloroalkanes, enabling the synthesis of a wide range of structurally diverse alkyl boronic, α-chloroboronic, and gem-diboronic esters. The reaction is facilitated by visible light irradiation and can produce products in moderate to good yields (up to 92%). The method demonstrates excellent functional group tolerance and is particularly effective for late-stage borylation of complex molecules. The process involves a C-Cl bond relay activation through inner-sphere electron transfer, overcoming the redox potential limits of unreactive alkyl chlorides. The synthetic robustness is further demonstrated on a preparative scale and applied to the late-stage diversification of complex molecules. Mechanistic studies using radical inhibition experiments, control reactions, and NMR spectroscopy support the proposed mechanism, which involves the formation of an exciplex and subsequent radical borylation or hydroborylation processes. This approach provides a versatile and efficient route for the synthesis of valuable boronic acids and their derivatives.This study reports a novel dinuclear gold-catalyzed divergent dechlorinative radical borylation of gem-dichloroalkanes, enabling the synthesis of a wide range of structurally diverse alkyl boronic, α-chloroboronic, and gem-diboronic esters. The reaction is facilitated by visible light irradiation and can produce products in moderate to good yields (up to 92%). The method demonstrates excellent functional group tolerance and is particularly effective for late-stage borylation of complex molecules. The process involves a C-Cl bond relay activation through inner-sphere electron transfer, overcoming the redox potential limits of unreactive alkyl chlorides. The synthetic robustness is further demonstrated on a preparative scale and applied to the late-stage diversification of complex molecules. Mechanistic studies using radical inhibition experiments, control reactions, and NMR spectroscopy support the proposed mechanism, which involves the formation of an exciplex and subsequent radical borylation or hydroborylation processes. This approach provides a versatile and efficient route for the synthesis of valuable boronic acids and their derivatives.