Tandem Generation and Trapping of Furo[3,4-c]isoquinoline Intermediates Leading to the Synthesis of Phenanthridine Ring Systems

One pot three component coupling of 3-alkynyl-4-isoquinoline carbonyl derivatives with Fischer carbene complexes and dienophiles leading to the synthesis of phenanthridine ring system has been investigated. This reaction involves the generation of furo[3,4-c]isoquinolines as transient intermediates, which undergo [4+2] cycloaddition with a dienophile in an inter/intramolecular fashion. In fact, this is the first report of the work on furo[3,4-c]isoquinoline intermediates.