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CsPbBr3holds promise as a visible light photocatalyst, but its instability in oxygen-rich and polar solvent environments poses a significant challenge for practical utilization. This study demonstrates the effectiveness of orthorhombic CsPbBr3nanocrystals (NCs) synthesized from dibromoisocyanuric acid. These NCs exhibit high efficiency as heterogeneous visible light photocatalysts (450–470 nm, 5 mol%) in a template-free aerobic thio/seleno etherification reaction involving 1,3,5-trimethoxybenzene, employing diaryl sulfides and diaryl selenides in acetonitrile (∼ 37.5). A novel surface treatment approach is proposed, utilizing electron-rich 1,3,5-trimethoxybenzene as a reactant to stabilize CsPbBr3NCs in situand address stability challenges in polar solvents and open-air environments. Additionally, among the four systems, the bromide-enriched orthorhombic CsPbBr3NCs exhibit markedly enhanced photocatalytic efficiency and stability compared to the cubic systems. The orthorhombic CsPbBr3NCs, with prolonged excited state lifetime, promote efficient electron transfer, leading to the generation of superoxide radical anions from the conduction band. These findings highlight the potential of perovskite nanocrystals and provide insights into their applications as visible light photocatalysts in organic transformations.

Herein we report a cascaded chalcogenation of aryl alkynoates or N-arylpropynamides using 9-mesityl-10-methylacridinium perchlorate as a visible light photocatalyst to obtain selectively either 3-sulfenylated/selenylated coumarins or spiro[4,5]trienones. In a radical initiated process, the spiro-cyclization reaction was favored due to the presence of a -OMe or -F substituent at the para position of the aryl group, which helped to stabilize the allylic radical intermediate formed during the reaction. Otherwise, 6-endo-trig cyclization led to 3-sulfenylated/selenylated coumarins. Overall, the new C–S/C–Se, C–C, and C═O bonds were formed in a single step. The Stern–Volmer quenching study, EPR experiments, light ON-OFF experiments, radical trapping experiments, etc., helped to understand the radical-based mechanism.

In a chlorinative cyclization, Mes-Acr-MeClO4acted as a visible-light photocatalyst to obtain 3-chlorocoumarins from aryl alkynoates and N-chlorosuccinimide (NCS). The radical initiated reaction proceeded in a cascading manner via Cl–addition to alkynoates. Next, 5-exo-trig spirocyclization and subsequent 1,2-ester migration led to the formation of C–C and C–Cl bonds.

Organosulfur compounds are omnipresent in many drugs, natural products, and functional materials; therefore, methodologies of C–S bond formation reactions are desirable in synthesis. The recent trend to control many chemical reactions by cooperative multiple weak interactions have emerged as one of the popular topics in supramolecular catalysis. Herein, we have made a collection of literature which utilizes multiple noncovalent interactions like H-bonding, solvent bonding, S–H···π, C–H···π, π–π stacking, charge-transfer complexation, etc. toward aryl C–S bond-formation reactions.

Herein we report the use of N‐iodosuccinimide (NIS) as a bifunctional reagent for a regio‐ and (E)‐selective C(sp2)‐H sulfonylation reaction of styrenes. Styrenes and sulfonyl hydrazides treated with NIS and potassium carbonate in ethanol at 70 °C resulted in (E)‐vinyl sulfones exclusively with good to excellent yields. NIS, plays a dual role to generate sulfonyl radical from sulfonyl hydrazides at an initial stage and finally gives β‐iodosulfone intermediate which was further converted to (E)‐vinyl sulfones. Overall, a sustainable method for mild, metal free, convenient, one pot and direct synthesis of (E)‐vinyl sulfones from styrenes are demonstrated via a C−S coupling reaction. Double trouble: N‐iodosuccinimide (NIS) is introduced as a bifunctional reagent towards development of a direct approach of functionalizing C(sp2)‐H of styrene in a regio‐ and (E)‐selective manner.

Herein we demonstrate that an anti‐Markovnikov selective thiol‐yne‐click (TYC) reaction could be achieved between phenyl acetylenes and thiophenols by exploiting a newly identified S−H⋅⋅⋅π non‐covalent interaction without using any catalysts, additives and solvents. Natural bond orbital (NBO) analyses also supported that S−H⋅⋅⋅π and cooperative π–π stacking interactions helped to promote this regioselective reaction. The hydrothiolated products were isolated in near quantitative yields. Also, the concept of self‐sorting was demonstrated when styrene, phenyl acetylene and thiophenols were reacted in one pot. Owing to the stronger S−H⋅⋅⋅π preference of ethynyl≡H over the vinyl=H hydrogen bond, selectively, TYC product formation was found to be dominating over the thiol‐ene‐click (TEC) product. It's clicking: By exploiting newly identified weak and non‐covalent S−H⋅⋅⋅π interaction anti‐Markovnikov selective thiol‐yne‐click (TYC) reaction could be achieved without using any catalyst, additive, or solvent.

We report a cascaded oxidative sulfonylation of N-propargylamine via a three-component coupling reaction using DABCO·(SO2)2(DABSO). 3-Arylsulfonylquinolines were obtained by mixing diazonium tetrafluoroborate, N-propargylamine, and DABSO under argon atmosphere in dichloroethane (DCE) for 1 h. In a radical pathway, DABSO was utilized as the sulfone source and an oxidant in this radical-mediated cascaded reaction.