Stereoselective Access to Tetra‐ and Tri‐Substituted Fluoro‐ and Chloro‐borylalkenes via Boron‐Wittig Reaction

Abstract

Reported herein is the efficient synthesis of tetra- and tri-substituted ( Z )-fluoro- and ( Z )-chloro-borylalkenes by the Boron–Wittig reaction of ketones and aldehydes with bench-top stable halo-diborylmethanes. The substrate scope is broad and the Boron–Wittig reaction proceeds from a diverse range of ketones and aldehydes including biologically relevant molecules with fluoro- or chloro-diborylmethanes, providing tetra- and tri-substituted ( Z )-fluoro- and ( Z )-chloro-borylalkenes in good yields with high stereoselectivity. The utilities of the obtained ( Z )-fluoro- and ( Z )-chloro-borylalkenes are highlighted by further modifications to afford fluoroalkene derivatives or all-carbon substituted alkene.