Cu-Catalyzed Dehydrogenative Olefinsulfonation of Alkyl Arenes

Air Induced Phosphoryl Radical Mediated Stereoselective Hydrosulfonylation of Alkynes via Halogen Atom Transfer: Ingress of Z-Vinyl Sulfones

The phosphoryl radical is well-known to participate in addition reactions with alkenes/alkynes. Here, we report a novel reaction mode of the phosphoryl radical where it participates in halogen atom transfer (XAT) with electron deficient vinyl halides instead of a facile addition reaction. Nevertheless, in comparison with aryl and alkyl halides, the exploitation of vinyl halides into a carbon radical via XAT is quite rare. This protocol provides an opportunity for direct hydrosulfonylation of numerous internal as well as terminal alkynes to get various Z-vinyl sulfones under environmentally benign conditions. Generation of the phosphoryl radical in the open air, water as a solvent, excellent functional group compatibility, and exceptional chemoselectivity are the attractive features of the present methodology.

Oxidative Dehydrogenation of Alkanes through Homogeneous Base Metal Catalysis

Preparing valuable olefins from cheap and abundant alkane resources has long been a challenging task in organic synthesis, which mainly suffers from harsh reaction conditions and narrow scopes. Homogeneous transition metals catalyzed dehydrogenation of alkanes has attracted much attention for its excellent catalytic activities under relatively milder conditions. Among them, base metal catalyzed oxidative alkane dehydrogenation has emerged as a viable strategy for olefin synthesis for its usage of cheap catalysts, compatibility with various functional groups, and low reaction temperature. In this review, we discuss recent development of base metal catalyzed alkane dehydrogenation under oxidative conditions and their application in constructing complex molecules.

A Dehydrogenative Inverse Electron Demand Diels-Alder Reaction for the Synthesis of Functionalized Pyranones

An efficient dehydrogenative inverse electron demand Diels-Alder reaction of isopropyl and prenyl benzene derivatives with electron-deficient dienes followed by decarboxylation has been reported for the first time. The much broader substrate scope of dienophiles and electron-deficient dienes led to biologically valuable pyranones in good to excellent yields.

Vinyl sulfone synthesis via copper-catalyzed three-component decarboxylative addition

The synthesis of vinyl sulfone derivatives via the reaction of arylpropiolic acids, K₂S₂O₅, and aryl boronic acids is reported. The CuBr₂/1,10-phenanthroline catalytic system in the presence of acetic acid provides the desired vinyl sulfones in moderate to good yield. Furthermore, the methodology features excellent functional group tolerance.

Visible-light-promoted divergent functionalizations of methylenecyclopropanes

Visible-light-induced monofunctionalization and difunctionalization of MCPs via ring-opening and cyclization processes have been developed for the syntheses of difluoromethyl compounds, alkyl compounds, halides, and sulfonyl compounds.