Terminal alkynes dehydrogenative cross-coupling

Tertiary amines are coupled with terminal alkynes to give propargylamines in an iron-catalyzed dehydrogenative cross-coupling reaction. Iron(II) chloride is used as a catalyst and di-terr-butyl peroxide as oxidant. Unsymmetrical alkynes are obtained in a reaction sequence involving two cross-coupling steps (Scheme 4-259). ... 

Scheme 4-259. Double iron-catalyzed dehydrogenative cross-coupling reaction of tertiary amines and terminal alkynes.

Copper Catalysts Direct oxidative functionalization of tertiary amines is of importance both enzymatically and synthetically. The combination of CuBr—TBHP has proved to be as an efficient system in the oxidative activation of sp3 C—H bonds adjacent to a nitrogen atom [10]. Various types of cross-dehydrogenative coupling (CDC) reactions have been developed, including compounds with activated methylene groups [11], indoles [12], and terminal alkynes (Scheme 11.2) [13]. Because 1,2,3,4-tetrahydroisoquinoline derivatives are important structure motifs of natural... 

The PPEs [14, 35, 36], which are dehydrogenated analogs of the poly(p-phenylene vinylene) s, display desirable optoelectronic properties that have found extensive use as emissive materials [37, 38]. PPE preparation is dominated by the Sonogashira Pd/Cu-catalyzed cross-coupling of aryl haUdes and terminal alkynes [39]. However, polymerizations under these conditions rarely achieve a high molecular weight, and defects such as diyne formation and alkyne crosshnking in the polymer backbone are endemic [14, 40]. Alkyne metathesis was envisioned as a complementary method to PPE synthesis, with much success. 

Recently, Su used terminal alkynes direcdy in a cross-dehydrogenative coupling reaction (100 108) with heterocycles including... 

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