Electrochemically programmable divergent semihydrogenation of enynes

The stereochemical configuration of diene motifs profoundly influences their physicochemical properties and biological activity. Despite this, general strategies for the divergent and stereodefined synthesis of isomeric dienes from common precursors remain scarce. Herein, we present an electrochemically programmable platform for the semihydrogenation of 1,3-enynes, achieving multidimensional selectivity control within a single reaction manifold to access diverse isomeric dienes. This platform selectively generates allenes via an electron transfer/proton transfer/hydrogen atom transfer (ET/PT/HAT) sequence in the absence of a catalyst, or 1,3-dienes upon introducing a cobalt catalyst that redirects the pathway through a Co(II)-H intermediate. Furthermore, fine modulation of the ligand architecture enables the selective formation of either Z- or E-configured dienes from the same starting material. This strategy marks a paradigm shift from conventional one-dimensional selectivity tuning to multidimensional selectivity programming, cooperatively leveraging the interplay of orthogonal parameters including the electrical regime, proton source, and catalyst. It thus offers a unified and tunable platform for accessing diverse, stereochemically defined diene libraries, crucial for advancements in medicinal chemistry and materials discovery.