Oxidant-dependent Cu-catalyzed alkynylation and aminomethylation: C–H versus C–C cleavage in TMEDA

Cross-Dehydrogenative Alkynylation: A Powerful Tool for the Synthesis of Internal Alkynes

Alkynes are among the most fundamentally important organic compounds and are widely used in synthetic chemistry, biochemistry, and materials science. Thus, the development of an efficient and sustainable method for the preparation of alkynes has been a central concern in organic synthesis. Cross-dehydrogenative coupling utilizing E-H and Z-H bonds in two different molecules can avoid the need for prefunctionalization of starting materials and has become one of the most straightforward methods for the construction of E-Z chemical bonds. This Review summarizes recent progress in the preparation of internal alkynes by cross-dehydrogenative coupling with terminal alkynes.

Copper-Catalyzed Tandem Sulfuration/Annulation of Propargylamines with Sulfur via C-N Bond Cleavage

Copper-catalyzed aerobic oxidative sulfuration and annulation of propargylamines with elemental sulfur is described. The tandem reaction involves C-N bond cleavage and the formation of multiple C-S bonds, affording 1,2-dithiole-3-thiones in good to excellent yields with good functional group tolerance.

Aerobic cross-dehydrogenative coupling of terminal alkynes and tertiary amines by a combined catalyst of Zn2+ and OMS-2

In the presence of ZnBr₂ and OMS-2, cross-dehydrogenative coupling of various terminal alkynes and tertiary amines to propargylamines efficiently proceeded.