Cyclopalladation of thiophene-substituted thiosemicarbazones

► Thiophene-substituted thiosemicarbazones form oligomeric palladacycles. ► Cyclopalladation occurs at the thiophene ring. ► Monomeric phosphine derivatives can be generated from the oligomers. ► The thiosemicarbazones act as dianionic, tridentate [C,N,S]2− ligands.