Ligand‐Controlled Divergent Synthesis of <i>cis/trans</i> ‐Trisubstituted Cycloalkenes via Pd‐Catalyzed [6+4] Cyclization

Medium-sized cycloalkenes are pivotal motifs in natural products and bioactive molecules, yet the divergent and stereoselective synthesis of their cis- and trans-isomers remains a long-standing challenge. To address this, we present a ligand-controlled, Pd-catalyzed [6+4] dipolar cyclization between N-PMB vinyl carbamates and azadienes that enables the divergent synthesis of both cis- and trans-trisubstituted 10-membered cycloalkenes. The key to this success is the ligand-modulated stability of the cis- and trans-π-allyl-Pd dipolar intermediates, allowing for high stereoselectivity by a simple switch of the phosphine ligand. This strategy provides a versatile and efficient platform for precisely constructing challenging medium-sized cycloalkenes with controlled olefin geometry.