Thiophenes in organotransition metal chemistry: Patterns of reactivity

Thiophenes, including benzothiophenes and dibenzothiophenes, undergo a variety of reactions with transition metal complexes that lead to products in which the thiophene is partially reduced or cleaved at a C-S bond. The specific types of reactivity depend on the modes of thiophene coordination to the metal, which in turn depend on the particular metal and its associated ligands. It is the intent of this review to organize these numerous reactions of thiophenes into categories that illustrate distinct patterns of reactivity. It is hoped that an understanding of such patterns will stimulate the use of thiophene-organotransition metal chemistry in synthetic organic chemistry.