Metal-Free Multicomponent Polymerization to Access Polythiophenes from Elemental Sulfur, Dialdehydes, and Imides

Polythiophene has attracted significant interest in recent years due to its distinctive optical properties, excellent thermal stability and favorable solubility. However, its synthesis remains a formidable challenge. Herein, a metal-free multicomponent polymerization (MCP) of elemental sulfur, cyclic imides and aromatic dialdehydes was disclosed, which offers a straightforward and sustainable route to access polythiophenes without metal contamination or complex purification processes. All monomers were inexpensive, readily available and easily modifiable, enabling efficient large-scale polymerization with high atom economy without releasing any harmful by-products. A series of well-defined polythiophenes were successfully prepared, with up to 24800 g/mol molecular weight and up to 88% yield. It highlighted metal-free MCP as a versatile and environmentally benign strategy for the synthesis of functional conjugated polymers.