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

1,1-Diborylalkenes can be transformed into (Z)-skipped dienes through Cu-I-phosphine catalyzed allylic coupling reactions. The energetically preferred formation of (Z)-alpha-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 (NaOBu)-Bu-t promotes cyclization/aromatization patterns via enyne intermediates.

Automated summary

This article describes the transformation of 1,1-diborylalkenes into (Z)-skipped dienes through Cu-I-phosphine catalyzed allylic coupling reactions. The preferential formation of (Z)-alpha-borylalkenyl copper (I) species and the subsequent nucleophilic attack explain the stereoselective nucleophilic substitution with allyl bromides. The eventual treatment of (Z)-skipped dienes with (NaOBu)-Bu-t promotes cyclization/aromatization patterns via enyne intermediates.