Copper Aryl-amine cross coupling

Cross-coupling reactions 5-alkenylboron boron compounds, 9, 208 with alkenylpalladium(II) complexes, 8, 280 5-alkylboron boron, 9, 206 in alkyne C-H activations, 10, 157 5-alkynylboron compounds, 9, 212 5-allylboron compounds, 9, 212 allystannanes, 3, 840 for aryl and alkenyl ethers via copper catalysts, 10, 650 via palladium catalysts, 10, 654 5-arylboron boron compounds, 9, 208 with bis(alkoxide)titanium alkyne complexes, 4, 276 carbonyls and imines, 11, 66 in catalytic C-F activation, 1, 737, 1, 748 for C-C bond formation Cadiot-Chodkiewicz reaction, 11, 19 Hiyama reaction, 11, 23 Kumada-Tamao-Corriu reaction, 11, 20 via Migita-Kosugi-Stille reaction, 11, 12 Negishi coupling, 11, 27 overview, 11, 1-37 via Suzuki-Miyaura reaction, 11, 2 terminal alkyne reactions, 11, 15 for C-H activation, 10, 116-117 for C-N bonds via amination, 10, 706 diborons, 9, 167... 

Waterlot, C., D. Couturier, and B. Rigo. 2000. Montmorillonite-palladium-copper catalyzed cross-coupling of methyl acrylate with aryl amines. Tetrahedron Lett. 41 317-319. 

The mechanism of palladium/aryl halide amination is very closely related to that of cross coupling, with displacement of the halide on palladium (or copper or nickel) by an amine or A-anion instead of the trans-metallation step. In the case of Cu and Ni catalysis, it may proceed through M(0)-M(11) or M(l)-M(lll) cycles. 

Alkyne cross-coupling reactions over the last 25 years have become one of the most valuable assets in the synthetic chemist s toolbox. The now famous Sonogashira coupling (50, 114) of terminal alkynes with aryl or vinyl halides is readily achieved with a palladium catalyst, a copper(l) cocatalyst, and amine base. In the catalytic cycle (Scheme 14a), copper-and palladium-alkyne complexes are the key intermediates that lead to coupling of R and R units via the alkyne. Analogously, the Stille coupling... 

Although thiols are generally stronger nucleophiles than alcohols and amines, the sensitivity of sulfides towards oxidation as well as the formation of disulfide made the cross-coupling between aryl halides and thiols difficult. From all previously reported results, it was foimd that only aryl iodides were suitable for this copper-catalyzed coupling process. 

Some of the optimized procedures for Stille and Sonogashira reactions involve the addition of copper cocatalysts to accelerate the cross-coupling procedures. A word of caution should be provided on the role of these additives in Pd-catalyzed amination procedures. Beletskaya and Davydov have reported the arylation of benzotriazole and of diary-lamines in polar organic or aqueous organic solvents using a combination of palladium and copper as catalyst.The arylation of amino acids has been reported under similar conditions.However, these reaction conditions are similar to classic Ullmann procedures for the synthesis of arylamines, except for the addition of palladium to the reaction mixture. In one case, subsequent work showed that the palladium species was not an essential component and that copper alone was the true catalyst in their reactions. An unusual accelerating effect of amino acid coordination to copper was used to explain the low-temperature Ullmann conditions. Beletskaya, however, showed that lower yields and a mixture of N1 and N2 arylation products were observed from the reactions of benzotriazole in the absence of copper and no reaction was observed in the absence of palladium. The conditions for this chemistry are, however, distinct enough from those of the majority of the aryl halide aminations to support the idea that a different mechanism may operate. 

Although not a direct N—H bond arylation, a related new reductive protocol for the amination of arylboronic acids has been developed which utilizes nitroso arenes. This reaction is certainly worthy of inclusion here, as it broadens our understanding of the cross-coupling processes of heteroatom-carbon bonds via N—O bonded species [61]. These new protocols rely on either stoichiometric amounts of CuCl (Scheme 4.23) or on catalytic amounts of copper(II) methylsalicy-late (CuMeSal) (Scheme 4.24). The need for stoichiometric amounts of a copper(I)... 

Reaction of Alkyl Amines Copper-catalyzed cross-coupling of aliphatic amines with aryl halides has made considerable progress. Several methods have used Ctil with p-amino alcohols L58 [42], amino acids L59, L60 [43], Al,Al-diethyl saUcylaldehyde L61 [44], or p-diketones L62-L65 [45] (Fig. 20.3). Among these, the protocol using p-diketones exhibited the superior results catalyzing the reaction even at room temperature (Scheme 20.19). 

Ligand-free systems have also been developed. For example, in 2010, Yong and Teo [78] reported the cross-coupling of alkyl amines and aryl iodides under ligand-free copper(I) iodide-catalyzed conditions. The reaction scope was quite good, and very good yields could be obtained, using both iodoarenes and bromoarenes and primary and secondary amines. This protocol in fact is an excellent... 

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