Silica gel-assisted preparation of multihalo-benzobthiophenes and its application to regioselective introduction of substituents

摘要

Multihalo-benzo[b]thiophenes bearing several different halogen substituents, such as bromo, chloro and iodo, are potentially regioselective building blocks, taking the diffrence in reactivity in cross coupling reactions into account. Especially, the angle between the substituents at 2-, 4- and 7-positions is about 90 degrees. So, 2,4,7-trihalobenzo[b]thiophenes can be used as ‘quasi T-shape’ molecular scaffold for the construction of large and sophisticated molecular systems.