Halogen dance reactions on thiophene derivatives

Derivatives of thiophene play a significant role in the development of photoelectronic materials. Among the various modification methods for thiophene, the halogen dance reaction (HDR) represents an efficient strategy, as it addresses the challenge of activating the inert β-site of thiophene. Since the first example of HDR on 2-bromothiophene was reported in 1951, numerous halogenated thiophene derivatives have been found to undergo HDR with high efficiency. In this review, we provide a comprehensive overview of HDR on thiophene derivatives, ranging from single thiophene units to dimers and fused thiophenes, with the aim of highlighting this key methodology in thiophene-based chemistry.