Diversity‐Oriented Synthesis of Thiophenes Via Switchable Annulation of Ninhydrin‐Derived MBH Esters With α‐Enolic Dithioesters

ABSTRACT

We report a diversity‐oriented synthesis of thiophene derivatives via a switchable annulation of ninhydrin‐derived MBH esters with α‐enolic dithioesters. By modulating the leaving groups of MBH esters (acetoxy vs. tert ‐butoxycarbonyloxy) and optimizing base‐solvent combinations, three distinct thiophene scaffolds are selectively obtained in moderate to good yields. The regioselective synthesis is enabled by switchable S ‐ or C ‐allylation pathways and subsequent divergent cyclization, providing a practical platform for accessing structurally diverse thiophene derivatives.