Strain‐Promoted 1,3‐Dithiolium‐4‐olates–Alkyne Cycloaddition

Abstract

Reported here is the reactivity of mesoionic 1,3-dithiolium-4-olates towards strained alkynes, leading to thiophene cycloaddition products. In the process, the potential of these dipoles towards orthogonal reaction with azides, allowing efficient double ligation reactions, was discovered. A versatile process to access benzo[c]thiophenes, in an unprecedented divergent fashion, was developed and provides a new entry to unconventional polyaromatic thiophenes.