A Catalytic Enantioselective Iodocyclization Route to Dihydrooxazines.
Rahul SureshAmit Kumar SimlandySantanu MukherjeePublished in: Organic letters (2018)
The first catalytic enantioselective synthesis of 5,6-dihydro-4H-1,2-oxazines bearing an oxygen-containing quaternary stereogenic center has been developed through iodoetherification of γ,δ-unsaturated oximes. This operationally straightforward reaction is catalyzed by Cinchona alkaloids-based bifunctional tertiary aminothiourea derivatives and furnishes the products generally in good to excellent yields and with moderate to high enantioselectivities (up to 97:3 er).