Copper thiophene carboxylate CuTC catalyst

Sarpong reported the synthesis of 21 by the application of rhodium-bound trimethylenemethane moieties. Allenylalkyne 19 was converted to fused pyrrole 20 in one-pot by treatment with tosylazide and a copper(I) thiophene-2-carboxylate (CuTc) catalyst to afford the expected triazole in situ. Subsequent addition of the rhodium catalyst effected decomposition of the triazole and delivered desired pyrrole 20 in good to excellent yields. A variety of alkyl and aryl substituents were tolerated under the reaction conditions and the methodology was ultimately used to enantioselectively prepare cycloprodiosin, a natural product produced by various bacterial strains such as Pseudoalteromonas (13JA4696). Shi and Gevorgyan disclosed a related... 

Liebeskind reported a copper-catalyzed Chan-Lam C-N crosscoupling methodology for JV-imination of boronic acids by using oxime O-carboxylates 291 as iminating agents and either Cu(I)-thiophene-2-carboxylate (CuTC) or Cu(OAc)2 as the catalyst under nonbasic and nonoxidizing conditions.Subsequently, the A-alkenylated a,3-unsaturated ketoxime 0-pentafluorobenzoates 293, were preeursors in a cascade reaction for the one-pot synthesis of tri-, tetra-, and penta-substituted pyridines 295 in moderate to excellent isolated yields. 

Transition metals are also useful catalysts for the title cycloaddition, and copper catalysts have proven especially effective. In an example from Furstner s lab, unactivated alkyne 17 undergoes an intramolecular Diels-Alder reaction catalyzed by copper thiophene 2-carboxylate (CuTC) to provide bicycle 18 in 95% yield. ... 

Copper(I) instead of palladium catalysts also promotes the cross-coupling of organic halides with organostannanes under mild condition. For example, a stoichiometric amount of CuTC (copper(I) thiophene-2-carboxylate) is capable of the... 

---