Aryl radical cyclisation onto pyrroles

The intramolecular cyclisation of aryl radicals onto a pyrrole is studied. The cyclisation allows the synthesis of either the spiropyrrolidinyloxindole or the pyrrolo[3,2-c]quinoline skeleton depending on the nature of the protecting group at the N-pyrrole atom. The regiochemistry of the cyclisation is not affected by the substituents on the benzene ring. Some limitations on the utility of tosylmethylisocyanide in pyrrole synthesis are also reported.