Domino bicyclization of 2,2-dihydroxyindene-1,3-dione with cyclic enaminones leading to isochromeno[4,3-b]indoles through Biotage Initiator耐士科技
New and practical acid-promoted domino bicyclization between 2,2-dihydroxyindene-1,3-dione and cyclic enaminones has been established for the formation of tetracyclic isochromeno[4,3-b]indoles under microwave heating. The present method simultaneously installs CeN, CeO, and CeC bonds, allowing direct assemble of functionalized isochromeno[4,3-b]indole skeleton with a wide diversity in substituents. The reaction features reliable scalability, flexibility of structural modification, and wide substratescope as well as operational simplicity, and it can avoid time-consuming and costly syntheses, tedious work-up, and isolation of intermediate.