Phosphine-Catalyzed [4 + 2] Annulation of Allenoate with Sulfamate-Derived Cyclic Imines: A Reaction Mode Involving γ'-Carbon of α-Substituted Allenoate.
Biming MaoWangyu ShiJianning LiaoHonglei LiuCheng ZhangHongchao GuoPublished in: Organic letters (2017)
A phosphine-catalyzed [4 + 2] cycloaddition of cyclic α-substituted allenoates with sulfamate-derived cyclic imines has been reported. Using dibenzylphenylphosphine as the nucleophilic catalyst, the reaction worked efficiently to yield various fused multicyclic heterocyclic compounds in high yields with excellent diastereoselectivities. It undergoes a new reaction mode involving γ'-carbon of α-substituted allenoate.