Synthesis of α-Haloboronates by the Halogenation of gem-Diborylalkanes via Tetracoordinate Boron Species

α-Haloboronates have a wide range of applications in organic chemistry as synthetic synthons; however, traditional synthetic methods of α-haloboronates are harsh and complicated. Herein, we used nBuLi as the nucleophilic reagent to attack the boron atom in gem-diborylalkanes to form tetracoordinate boron species and successfully achieved α-chloroboronates and α-bromoboronates with readily accessible electrophilic halogen reagents (NCS and NBS). The reaction is transition-metal-free and features a broad substrate scope and diversified valuable products.