Selective Synthesis of Benzofuro[2,3-c]isoquinolines and 5,6-Dihydro-7H-benzo[c]benzofuro[2,3-e]azepin-7-ones from 4-Diazoisoquinolin-3-ones and Salicylaldehydes

A catalyst-controlled selective synthesis of benzofuro[2,3-c]isoquinolines and 5,6-dihydro-7H-benzo[c]benzofuro[2,3-e]azepin-7-ones from salicylaldehydes and 4-diazoisoquinolin-3-ones has been developed. The Co(III)-catalyzed reactions furnished benzofuro[2,3-c]isoquinolines as major products, while the Rh(III)-catalyzed reactions afforded 5,6-dihydro-7H-benzo[c]benzofuro[2,3-e]azepin-7-ones as major products.