The first example of an intermolecular thiolyne-ene coupling reaction is reported for the one-pot construction of CÀ S and CÀ 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 CÀ S threeelectron 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-yneene reaction were obtained in good yields with high selectivity. They can serve as stable precursors for synthesizing synthetically demanding activated 1,3-dienes.

Visible light photocatalysis is a rapidly developing branch of chemical synthesis with outstanding sustainable potential and improved reaction design. However, the challenge is that many particular chemical reactions may require dedicated tuned photoreactors to achieve maximal efficiency. This is a critical stumbling block unless the possibility for reactor design becomes available directly in the laboratories. In this work, customized laboratory photoreactors were developed with temperature stabilization and the ability to adapt different LED light sources of various wavelengths. We explore two important concepts for the design of photoreactors: reactors for performing multiple parallel experiments and reactors suitable for scale-up synthesis, allowing a rapid increase in the product amount. Reactors of the first type were efficiently made of metal using metal laser sintering, and reactors of the second type were successfully manufactured from plastic using fused filament fabrication. Practical evaluation has shown good accuracy of the temperature stabilization in the range typically required for organic synthesis for both types of reactors. Synthetic application of 3D printed reactors has shown good utility in test reactions—furan C–H arylation and thiol-yne coupling. The critical effect of temperature stabilization was established for the furan arylation reaction: heating of the reaction mixture may lead to the total vanishing of photochemical effect.

The first example of an intermolecular thiolyne-ene coupling reaction is reported for the one-pot construction of CÀ S and CÀ 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 CÀ S threeelectron 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-yneene reaction were obtained in good yields with high selectivity. They can serve as stable precursors for synthesizing synthetically demanding activated 1,3-dienes.