Amines, copper® bromide

C for 20 hours. A catalyst system based on copper bromide, an amine, and oxygen was employed in these polymerizations, resulting in PPO yields as high as 83% and M s as high as 1.7 x 104 g/mol. 

Suitable catalysts are copper(I) salts [e.g., Cu(I) chloride, bromide, and sulfate] in combination with amines to form oxidation sensitive phenolates. The amine/copper salt ratio must be made as large as possible, to minimize the formation of diphenylquinone and to give a high molecular weight. 

The structure of copolymers obtained by ATRP copolymerization of 5,6-benzo-2-methylene-l,3-dioxepane (BMDO) with H-butyl acrylate ( BA) using ethyl 2-bromoisobutyrate and iV,iV,iV, iV ,iV -pentamethyldiethylenetri-amine/copper(l) bromide, as the initiator and catalyst, respectively, was studied by ID and 2D NMR techniques, which revealed a quantitative ring opening of BMDO in the copolymerization <2005PLM11698>. For a similar study of copolymers of BMDO and styrene, see <2003MM6152>, and with methyl methacrylate, <2003MM2397>. 

For amination with aliphatic amines, copper catalysis is normally superior to palladium catalysis, e.g., <2006T4435>. Thus, reactions of primary or secondary amines, including pyrrolidine and morpholine, with 5-bromopyrimidine using copper bromide and a phosphite ligand give 5-aminopyrimidines in excellent yields (Scheme 116) <2006T4435, 2005OL3965>. 

COPPER BROMIDE (7789-45-9) BFjCu Aqueous solution is an acid. Incompatible with bases, inducing amines, amides, and inorganic hydroxides strong oxidizers, including chlorine, fluorine, peroxides and hydroperoxides potassium. 

Typically, phosphoms-based ligands are used to complex no-copper transition metals. Whereas, nitrogen-containing ligands have been used in copper-and iron-mediated ATRP, including 1,1,4,7,10,10-Hexamethyltriethylenetetramine (HMTETA), 2,2 -bipyridine (Bipy), NJ l,N d l ,N -pentamethyldiethylenetriamine (PMDETA), and tris[2-(dimethylamino)ethyl]amine (MceTREN) [26, 27], The activation rate constants for these ligands in copper bromide mediated ATRP and the proposed reaction mechanism of copper/2,2 -bipyridine are shown in Fig. 3.5. 

Y. Shen, S. Zhu, F. Zeng, R. H. Pelton, Atom transfer radical polymerization of methyl methacrylate by silica gel supported copper bromide/multidentate amine. Macromolecules 2000, 33, 5427-5431. 

Scheme 9 Copper bromide/L23-catalyzed reactions of alkyl amines and N-heterocycles with aryl or heteroaryl iodides...

Although It IS possible to prepare aryl chlorides and aryl bromides by electrophilic aromatic substitution it is often necessary to prepare these compounds from an aromatic amine The amine is converted to the corresponding diazonmm salt and then treated with copper(I) chloride or copper(I) bromide as appropriate... 

Copper amine azide Copper tetramine nitrate Crotonaldehyde, stabilized Cyanogen bromide Cyanuric triazide... 

For the in situ preparation of the required arenediazonium salt from an aryl amine by application of the diazotization reaction, an acid HX is used, that corresponds to the halo substituent X to be introduced onto the aromatic ring. Otherwise—e.g. when using HCl/CuBr—a mixture of aryl chloride and aryl bromide will be obtained. The copper-(l) salt 2 (chloride or bromide) is usually prepared by dissolving the appropriate sodium halide in an aqueous solution of copper-(ll) sulfate and then adding sodium hydrogensulfite to reduce copper-(ll) to copper-(1). Copper-(l) cyanide CuCN can be obtained by treatment of copper-(l) chloride with sodium cyanide. 

Some other examples of metal-catalyzed substitutions are given in Scheme 11.10. Entries 1 to 3 are copper-catalyzed reactions. Entry 1 is an example of arylation of imidazole. Both dibenzylideneacetone and 1,10-phenanthroline were included as ligands and Cs2C03 was used as the base. Entry 2 is an example of amination by a primary amine. The ligand used in this case was (V,(V-diethyl sal icyl amide. These conditions proved effective for a variety of primary amines and aryl bromides with both ERG and EWG substituents. Entry 3 is an example of more classical conditions. The target structure is a phosphodiesterase inhibitor of a type used in treatment of asthma. Copper powder was used as the catalyst. 

Iminium ions, generated in aqueous solution from secondary amines and formaldehyde, undergo a Barbier-type allylation mediated by tin, aluminum, and zinc. The reaction is catalyzed by copper and produces tertiary homoallylamines in up to 85% yield.67 The imines generated in situ from 2-pyridinecarboxaldehyde/2-quinolinecarboxaldehyde and aryl amines undergo indium-mediated Barbier allylation in aqueous media to provide homoallylic amines.68 Crotyl and cinnamyl bromides... 

A mixture of (triisopropyl phosphito)copper(I) bromide (17.6 g, 0.05 mol) and l-bromo-2,2-diphenylethylene (9.1 g, 0.035 mol) was heated at 200°C for 1 h under a nitrogen atmosphere in a flask equipped with a Vigreaux column topped by a Dean-Stark trap. The alkyl halide produced in the reaction was collected in the trap. After cooling, the reaction mixture was poured into toluene (60 ml), and ethylenedi-amine was added (5 ml). After filtering and washing the precipitate with toluene, the combined toluene solutions were washed with 10% hydrochloric acid (10 ml) and water (10 ml), dried over magnesium... 

Most of the work on the C-N bond-forming crosscoupling reactions has concentrated on the formation of aromatic C-N bonds. Recent studies show that the application of cross-coupling reactions to alkenyl halides or triflates furnished enamines (Scheme 19) (for palladium-catalyzed reaction, see 28,28a-28d, and for copper-catalyzed reaction, see 28e-28g). Brookhart et al. studied the palladium-catalyzed amination of 2-triflatotropone 109 for the synthesis of 2-anilinotropone 110.28 It was found that the reaction of 109 proceeded effectively in the presence of racemic BINAP and a base. As a simple method for the synthesis of enamines, the palladium-catalyzed reactions of alkenyl bromide 111 with secondary amine were achieved under similar conditions.2841 The water-sensitive enamine 112 was isolated as pure compound after dilution with hexane and filtration through Celite. The intramolecular cyclization of /3-lactam 113, having a vinyl bromide moiety, was investigated by Mori s... 

The utility of the copper/Taniaphos-catalyzed allylic alkylation was further illustrated in two subsequent reports. The application of aliphatic allylic bromides containing protected alcohols and amines leads to the efficient synthesis of bifunctional building blocks (Scheme 15) . ... 

The reaction with ammonia or amines, which undoubtedly proceeds by the SNAr mechanism, is catalyzed by copper8" and nickel105 salts, though these are normally used only with rather unreactive halides.106 This reaction, with phase transfer catalysis, has been used to synthesize triarylamines.107 Copper ion catalysts (especially cuprous oxide or iodide) also permit the Gabriel synthesis (0-58) to be applied to aromatic substrates. Aryl bromides or iodides are refluxed with potassium phthalimide and Cu 0 or Cul in dimethylacetamide to give N-aryl phthalimides, which can be hydrolyzed to primary aryl amines.108... 

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