Site‐Selective (Z)‐α‐Borylalkenyl Copper Systems for Nucleophilic Stereodefined Allylic Coupling

Abstract

1,1‐Diborylalkenes can be transformed into (Z)‐skipped dienes through CuI‐phosphine catalyzed allylic coupling reactions. The energetically preferred formation of (Z)‐α‐borylalkenyl copper (I) species and the subsequent nucleophilic attack, explains the stereoselective nucleophilic substitution with allyl bromides. The eventual treatment of (Z)‐skipped dienes with NaOtBu promotes cyclization/aromatization patterns via enyne intermediates.