Enantioselective Synthesis of Boron‐Substituted Quaternary Carbons by NHC—Cu‐Catalyzed Boronate Conjugate Additions to Unsaturated Carboxylic Esters, Ketones, or Thioesters.

A Cu-catalyzed method for enantioselective boronate conjugate additions to trisubstituted alkenes of acyclic α,β-unsaturated carboxylic esters, ketones, and thioesters is developed.