Lewis Base/Alkali Metal Halide Co-catalyzed Allylic Alkylation of gem-Diborylalkanes with MBH Carbonates for the Construction of tert-Alkylboronic Esters

Abstract

A mild and efficient DMAP/KF co-catalyzed allylic alkylation of gem-diborylalkanes with MBH carbonates has been developed, providing a series of tertiary alkylboronate esters in moderate to excellent yields. Moreover, this strategy is also applicable to the construction of secondary alkylboronic esters using DABCO and LiCl as co-catalysts. The late-stage modification of bioactive molecules, scaled-up reaction and downstream derivatizations documented the practicability of this method. Primary mechanistic studies implicated the alkali metal halide as a co-catalyst is crucial for the observed reactivity.