Cu-catalyzed enantioselective assembly of axially chiral allylic boronates

Highly enantioselective construction of axially chiral cyclohexylidenes is difficult and challenging due to their structural peculiarities. The development of efficient method for the assembly of novel axially chiral cyclohexylidenes becomes particularly important in axial chirality. Chiral allylborons have become a focus of interest in chemical community as an important synthon as well as a backbone structure, yet an efficient and practical synthetic method for the synthesis of axially chiral allylborons have not been disclosed so far. Herein, we report a copper-catalyzed strategy which could readily access enantiopure axially chiral allylborons under mild conditions. The obtained axially chiral allylborons can also be subjected to a number of subsequent transformations as well as late modification of drug molecules, thus demonstrating the validity of the developed method.