A Very Short and Efficient Palladium-Catalyzed Access to the 3,4-Dihydro- 2H-1,4-Benzoxazine Structure

Palladium(0)-catalyzed annulation of N-substituted-2-aminophenols with propargylic methyl carbonates afforded the corresponding 3,4-dihydro-2-alkylidene- and 3,4-dihydro-3-alkylidene-2H-benzo[b] [1,4]oxazines; a judicious choice of the substituent at nitrogen allowed the preparation of one of the regioisomers.