Synthesis of thioesters using an electrochemical three-component reaction involving elemental sulfur.

An electrochemical three-component reaction involving elemental sulfur is disclosed for achieving a metal-free, oxidant-free synthesis of thioesters in a high atom-economical, step-economical and chemoselective manner. A mechanistic investigation indicates that the use of elemental sulfur to trap acyl radical derived from radical umpolung of α-keto acid with an electrochemical design can efficiently generate a carbonyl thiyl radical, which can further be captured by diazoalkane to afford various thioesters.

Metal-free polyporphyrin based photocatalysts for the functionalization of C(sp3)-H bonds in water.

The development of metal-free and water-compatible photocatalysts for visible light-induced environmentally friendly transformation in water is highly desirable. Herein, two types of polyporphyrin based heterogeneous photocatalysts with different water-solubility in water, namely, an insoluble polymer and a water-dispersible nanoparticle, were disclosed. Both of them exhibited excellent photocatalytic activity in visible-light induced functionalization of C(sp3)-H bonds on a wide range of substrates in water. The reusable and recyclable photocatalysts provided a green and sustainable approach for photocatalysis in water.

Copper-Catalyzed One-Step Formation of Four C-N Bonds toward Polyfunctionalized Triazoles via Multicomponent Reaction.

A novel four-component reaction of alkynes, amines, azides, and 2H-azirines has been developed for the first time by the efficient formation of four C-N bonds in one step under mild conditions, rapidly preparing polyfunctionalized triazoles with molecular diversity involving three different intermediates of copper-acetylide, copper-allenylidene, and copper-vinyl nitrene. Propargylic ester is disclosed as a "three-in-one" building block possessing triplicate cycloaddition and nucleophilic and electrophilic properties, which could enable such a four-component transformation by high yields, broad substrate scope, and functionalization.

Copper-catalyzed Z-selective synthesis of acrylamides and polyacrylamides via alkylidene ketenimines.

It remains very important to discover and study new fundamental intermediates consisting of carbon and nitrogen as the abundant elements of organic molecules. The unique alkylidene ketenimine could be formed in situ under mild conditions by an unexpected copper-catalyzed three-component reaction of alkyne, azide and water involving a successive cycloaddition, N2 extrusion and carbene-assisted rearrangement. Only Z-α,ß-unsaturated amides instead of E-α,ß-unsaturated amides or triazoles were acquired from alkylidene ketenimines with excellent selectivities and stereospecificities. In addition, a series of "approximate" alternating copolymers (poly (triazole-alt-Z-acrylamides)) with high Mns and yields were efficiently afforded by multicomponent polymerization through a very simple operation basing on this multicomponent reaction.