Silver-Catalyzed One-Pot Access to Diastereoselective Benzo[5,6]oxepino[2,3-c]pyrroles via Formal (5+2)-Annulation of Donor-/Acceptor-Type Aryl Vinyl Diazosuccinimide with Ketones

Abstract

Dihydrobenzoxepine scaffold is one of the important and useful oxygenated heterocycles. A one-pot diastereoselective synthesis of dihydrobenzoxepines has been achieved via a formal (5+2)-cycloaddition of vinyl diazosuccinimides and ketones under silver catalysis. Aliphatic as well as aromatic methyl ketones afforded the corresponding dihydrobenzoxepines with high regio- and chemo-selectivity. Further insight into the reaction mechanism has been established using control experiments and time-dependent NMR studies.