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.