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 reactions and downstream derivatizations demonstrate the practicability of this method. Preliminary mechanistic studies indicated that the alkali metal halide co-catalyst is crucial for the observed reactivity.