A Single Cu(II) Catalyst for the Three-Component Coupling of Diverse Nitrogen Sources with Aldehydes and Alkynes

Abstract

A single Cu(II) catalyst without the addition of ligand or base couples a diverse range of nitrogen sources with alkynes and aldehydes bearing alkyl, halogenated, silyl, aryl, and heteroaryl groups. The first example of a copper-catalyzed alkynylation involving p-toluenesulfonamide provides high yields of N-Ts-protected propargylamines. The superior activity of copper(II) triflate also allows this three-component alkynylation to incorporate a ketone.

Copper(I)‐Catalyzed Decarboxylative Coupling of Propiolic Acids with Secondary Amines and Aldehydes

“…Different temperatures were also tested, but did not improve the yields (Table 1, Entries 11 and 12). Remarkably, Cu(OTf) 2 was slightly less efficient than CuI (Table 1, Entry 7) 31. Finally, when the reaction was conducted by using conventional heating under the same conditions, the desired propargylamine 4{1} was obtained in a yield of 79 % after an extended reaction time of 6 h (Table 1, Entry 14).…”

“…To investigate the scope of this decarboxylative A 3 ‐coupling reaction, various aldehydes 1 were examined under the above optimized conditions (Table 1, Entry 4) 31. For aliphatic aldehydes, the reaction afforded the corresponding products 4 in moderate to good yields (Table 2, Entries 1–6).…”

CuII@PAA/PVC mesoporous fibers: A hybrid wedding as a high‐performance versatile heterogeneous catalyst for A3, KA2, and decarboxylative A3 reactions

“…However, to date, only a few reports on the KA 2 couplings have been reported. Examples of homogeneous catalysts which have been employed include CuI, CuBr, Cu (OTf) 2 , AuBr 3 , CuCl 2 /Ti(OEt) 4. The representative heterogeneous catalysts covered Amberlyst A‐21 supported CuI, CuNPs@ZnO–PTh, CuO/Fe 2 O 3 NPs, nano Cu 2 O–ZnO .…”

Zinc(II)‐Catalyzed Synthesis of Propargylamines by Coupling Aldimines and Ketimines with Alkynes

“…N-substituents such as thiophosphinoyl [14] and p-toluenesulfonyl [11] groups also enhance the reactivity of the corresponding ketimines towards catalytic alkyne additions.…”