An intramolecular inverse electron demand Diels-Alder approach to annulated α-carbolines

Intramolecular inverse electron demand cycloadditions of isatin-derived 1,2,4-triazines with acetylenic dienophiles tethered by amidations or transesterifications proceed in excellent yields to produce lactam- or lactone-fused alpha-carbolines. Beginning with various isatins and alkynyl dienophiles, a pilot-scale library of eighty-eight alpha-carbolines was prepared by using this robust methodology for biological evaluation.