Copper‐Catalyzed Asymmetric Acylboration of 1,3‐Butadienylboronate with Acyl Fluorides

Abstract We report herein a Cu‐catalyzed regio‐, diastereo‐ and enantioselective acylboration of 1,3‐butadienylboronate with acyl fluorides. Under the developed conditions, the reactions provide ( Z )‐β,γ‐unsaturated ketones bearing an α‐tertiary stereocenter with high Z ‐selectivity and excellent enantioselectivities. While direct access to highly enantioenriched E ‐isomers was not successful, we showed that such molecules can be synthesized with excellent E ‐selectivity and optical purities via Pd‐catalyzed alkene isomerization from the corresponding Z ‐isomers. The orthogonal chemical reactivities of the functional groups embedded in the ketone products allow for diverse chemoselective transformations, which provides a valuable platform for further derivatization.