A domino annulation reaction under Willgerodt-Kindler conditions
(Chemical Equation Presented) Butanone side chains at arenes and hetarenes, efficiently introduced by a Heck-type reaction, are transformed to annulated thieno[3,2-b]thiophenes in a domino redox process under Willgerodt-Kindler conditions. A nucleophilic aromatic substitution with an intermediary thioenolate is a reasonable key step of this process.