Acidic Hydrogen-Tethered Allylic Carbonates for Phosphine-Catalyzed (4+2) Annulation of Sulfamate-Derived Cyclic Imines

The acidic hydrogen-tethered allylic carbonates were successfully applied in phosphine catalysis. Their (4 +2) annulation reaction with sulfamate-derived cyclic imines under phosphine catalysis worked well to produce tetrahydropyridine-fused heterocyclic compounds in high yields. A moderate ee was obtained in the initial screening. The zwitterionic intermediate produced through in-situ deprotonation functioned as a four-membered synthon.

Automated summary

The acidic hydrogen-tethered allylic carbonates were successfully applied in phosphine catalysis, showing high yields in (4+2) annulation reactions with sulfamate-derived cyclic imines. A moderate ee was obtained, and the zwitterionic intermediate acted as a four-membered synthon.