We report a general protocol for the convergent synthesis of 1,4-dicarbonyl Z-alkenes form alkynes using α-diazo sulfonium triflate and water. The CO, CC, and C−H bonds are formed under mild conditions with a wide range of functional groups tolerated. The reaction exhibits excellent Z-selectivity and complete regioselectivity. The resulting 1,4-dicarbonyl Z-alkenes can smoothly undergo follow-up conversion to a variety of heteroaromatic scaffolds. Moreover, the reaction also provides a facile access to the corresponding deuterated Z-alkenes and deuterated heteroarenes with a high level of deuterium incorporation (90− 97% D-inc.) by directly using D 2 O, thus rendering the method highly valuable. The comprehensive mechanistic studies indicate that a free carbyne radical intermediate is formed via the photocatalytic single electron transfer process, and KH 2 PO 4 plays a crucial role in significant improvements on yield and selectivity based on density-functional theory calculations, providing a new direction for radical coupling reactions of diazo compounds.

A transition metal/ligand-free disulfuration of anilines with disulfur transfer reagents (dithiosulfonate or tetrasulfide) is reported herein. The reaction, which can be considered as a reductive disulfuration variation of the classic Sandmeyer reaction, is performed under mild conditions and exhibits broad scope across the aniline substrate and disulfur transfer reagent classes. The gram-scale synthesis of disulfides is successfully achieved through this method, rendering the approach highly valuable.

In this study, we outline a general method for photocatalyzed difunctionalization of alkenes, a diene, alkynes, 1,3-enynes, and [1.1.1]propellane using dithiosulfonate reagents (ArSO 2 -SSR) with improved atom economy. Both "ArSO 2 -" and "-SSR" on the dithiosulfonate are transferred under mild conditions with broad substrate scope, high stereoselectivity, and complete regioselectivity. Significantly, the resulting dithiosulfonylated styrene is a general and practical nucleophilic disulfuration reagent, reacting with a variety of electrophiles efficiently. Both reactions can be conducted on gram scale, rendering the approach highly valuable.

Herein, we report a novel organocatalytic process for synthesis of complex 1,3,4-oxadiazoles from readily accessible aldehydes. By exploiting the nucleophilicity of the putative Breslow intermediate and the inherent electrophilicity of α-diazo iodonium triflate, we have found that N-heterocyclic carbene catalyst promotes efficient cyclization of various aldehydes and α-diazo iodonium triflates. The reaction proceeds under mild conditions with a wide range of functional group tolerance. The heterocyclic products can be readily further functionalized, rendering the protocol highly valuable.

In this study, we outline a general method for photocatalyzed difunctionalization of alkenes, a diene, alkynes, 1,3‐enynes, and [1.1.1]propellane using dithiosulfonate reagents (ArSO2‐SSR) with improved atom economy. Both “ArSO2‐” and “‐SSR” on the dithiosulfonate are transferred under mild conditions with broad substrate scope, high stereoselectivity, and complete regioselectivity. Significantly, the resulting dithiosulfonylated styrene is a general and practical nucleophilic disulfuration reagent, reacting with a variety of electrophiles efficiently. Both reactions can be conducted on gram scale, rendering the approach highly valuable.