Ring-Opening/Ring-Closing Protocols from Nitrothiophenes: Easy Access toN-Fused Pyrroles through a Tandem 1,6-H Shift/6π-Electrocyclization

The ring opening of 3-nitro-4-(phenylsulfonyl)thiophene with amines and proper modification of the resulting 1,3-diene enables a simple and versatile approach to N-fused pyrroles of both synthetic and biological interest through 1,6-H shift followed by 6π 1,5-electrocyclization. This protocol is effectively driven to the isolated pyrroles by an easy aromatization.