Physics

Organic chemistry

Ene reaction

Photocatalysis

Electron transfer

Photon upconversion

Catalysis

Intermolecular force

Quantum yield

Chemistry

Molecule

Coupling reaction

Quantum mechanics

Regioselectivity

Photochemistry

Fluorescence

Angewandte Chemie International Edition

The first example of an intermolecular thiol-yne-ene coupling reaction is reported for the one-pot construction of C-S and C-C bonds. Thiol-yne-ene coupling opens a new dimension in building molecular complexity to access densely functionalized products. The employment of Eosin Y/DBU/MeOH photocatalytic system suppresses hydrogen atom transfer (HAT) and associative reductant upconversion (via C-S three-electron σ-bond formation). Investigation of the reaction mechanism by combining online ESI-UHRMS, EPR spectroscopy, isotope labeling, determination of quantum yield, cyclic voltammetry, Stern-Volmer measurements and computational modeling revealed a unique photoredox cycle with four radical-involving stages. As a result, previously unavailable products of the thiol-yne-ene reaction were obtained in good yields with high selectivity. They can serve as stable precursors for synthesizing synthetically demanding activated 1,3-dienes.

Intermolecular Photocatalytic Chemo‐, Stereo‐ and Regioselective Thiol–Yne–Ene Coupling Reaction