Transition-metal-catalyzed cyclization reactions using vinyl and ethynyl benzoxazinones as dipole precursors

Abstract Vinyl and ethynyl benzoxazinones have recently received increasing attention from organic chemists because they are powerful tools for the construction of structurally diverse aza -heterocycles. A number of catalytic cyclization reactions have been developed that used these two reagents and required the presence of a transition-metal catalyst (i.e., palladium, iron, and copper). This review highlights the design and synthesis of these versatile reagents, and their applications as precursors for transition-metal-containing 1,4-dipoles in dipolar cyclizations and related cascade reactions. The general mechanisms and asymmetric inductions are briefly discussed as well.