Synthesis of Heteroarenes via Radical Cyclisation onto Nitriles

Abstract

A new protocol for the synthesis of tetracyclic nitrogen heteroarenes using cascade radical cyclisation has been developed. The key steps involve 5-exo vinyl radical cyclisation onto nitriles to yield intermediate iminyl radicals which cyclise onto an arene rings. Rings A-D of the anticancer alkaloids camptothecin, mappicine and nothapodytines A and B have been synthesised using this protocol.