Facile Synthesis of α-Polythienyls via 1,4-Diketones

Unsubstituted and substituted linear polythienyls including thiophenes in both even and odd numbers are conveniently prepared from the Michael addition of thiophenecarboxaldehydes to Mannich bases and the vinyl sulfone. Cyclization of the resulting 1,4-diones with Lawesson's reagent gives α-polythienyls.