Copper II amines

The whole procedure, including the filtration, is performed under a nitrogen atmosphere. To a solution of 3.26 g (24.0 mmol) of ( + )-(5 )-l-phenyl-2-propanamine (amphetamine) in 20 mL of methanol is added a solution of 807 mg (6.0 mmol) of copper(II) chloride in 10 mL of methanol at 25 "C with stirring. After 30 min, 432 mg (3.0 mmol) of 2-naphthalenol in 10 mL of methanol are added and the total volume brought up to 60 mL with methanol. After 20 h, the brown precipitate (a binaphthalenol-copper(II) amine complex) is destroyed with 40 mL of 4 N hydrochloric acid. After all of the precipitate is dissolved, 100 mL of water are added and the product crystallizes from the solution. It is isolated by filtration, and dried in vacuo yield 421 mg (98%) 96% ee (T-isomer). 

Khier et al. [30] determined mefenamic acid after complexation with copper(II) amine sulfate. The complex is extracted with chloroform and treated with diethyldithiocarbamate solution, whereupon another copper (II) complex (wavelength maximum of 430 nm) is formed. Beer s law is followed over the mefenamic acid concentration range of 6 18 pg/mL. The method was applied successfully to the determination of mefenamic acid in bulk samples and in pharmaceutical preparations, with recoveries of 98.0-101.0%. 

Alpdogan and Sungur [50] developed an indirect atomic absorption spectroscopy method for the determination of mefenamic and flufenamic acids, and diclofenac sodium, based on the complexation with copper (II) amine sulfate. The complex was extracted into chloroform, and the concentrations of substances were determined indirectly by AAS measurement of copper after re-extraction into 0.3 N nitric acid solution. The developed method was applied to the assay of the substances in commercial tablet formulations. The results were statistically compared with those obtained by HPLC method by t- and F tests at 95% confidence level. Calculated t and F values were both lower than the table values. 

Naphthol can successfully be dimerized oxidatively, selectively through the o-site to give (22) using copper(II)-amine complexes (70%) or manganese(III) acetylacetonate (69%), and o-o coupling is the major paAway (90%) on ferricyanide oxidation of the trisubstituted phenol (23) to the orthodiphenoqui-none (24). In this context it is of interest that a compound obtained (74%) on ferricyanide oxidation of... 

Copper(II)-amine complexes. A typical complex is prepared from Cu(N03)2-3H2O (1 equiv.) and a-phenylethylamine (3 equiv.) in CH3OH. 

Copper(II) acetate-Morpholine, 115 Copper(II)-amine complexes, 114-115 Copper(l) bromide, 116-117 Copper(I) bromide-Dimethyl sulfide, 117-118, 235 Copper(II) bromide, 196 Copper(I) f-butoxide, 311 Copper(l) chloride, 118-119, 288 Copper(I) chloride-Tetra-n-butylam-monium chloride, 119... 

Copper(II)-amine complexes are widely used and very effective phenolic oxidative coupling reagents. Since the reaction proceeds within the copper coordinative sphere, chiral amine ligand does induce the enantioselective oxidative couplings of phenols such as 2-naphthol [39-41], or 9-phenanthrol [42,43] to form respective atropisomeric... 

The suggested mechanism (eq 23) of the V-arylation starts with formation of a copper (II)-amine complex. Transmetallation by the arylboronic acid followed by reductive elimination finally affords the V-aryl product. ... 

Copper(II) amine complexes are very effective catalysts for the oxidative coupling of 2-naphthols to give symmetrical l,F-binaphthalene-2,2 -diols. Recent work has extended this methodology to the cross-coupling of various substituted 2-naphthols. For example, 2-naphthol and 3-methoxycarbonyl-2-naphthol are coupled under strictly anaerobic conditions using CuCU/tert-butylamine in methanol to give the unsymmetrical bi-naphthol in 86% yield (eq 20). 

Crystal stmctures of complexes of copper(II) with aromatic amine ligands and -amino acids " " and dipeptides" have been published. The stmctures of mixed ligand-copper complexes of L-tryptophan in combination with 1,10-phenanthroline and 2,2 -bipyridine and L-tyrosine in combination with 2,2 -bipyridine are shown in Figure 3.2. Note the subtle difference between the orientation of the indole ring in the two 1,10-phenanthroline complexes. The distance between the two... 

Unfortunately, addition of copper(II)nitrate to a solution of 4.42 in water did not result in the formation of a significant amount of complex, judging from the unchanged UV-vis absorption spectrum. Also after addition of Yb(OTf)3 or Eu(N03)3 no indications for coordination were observed. Apparently, formation of a six-membered chelate ring containing an amine and a ketone functionality is not feasible for these metal ions. Note that 4.13 features a similar arrangement and in aqueous solutions, likewise, does not coordinate significantly to all the Lewis acids that have been... 

Note that for 4.42, in which no intramolecular base catalysis is possible, the elimination side reaction is not observed. This result supports the mechanism suggested in Scheme 4.13. Moreover, at pH 2, where both amine groups of 4.44 are protonated, UV-vis measurements indicate that the elimination reaction is significantly retarded as compared to neutral conditions, where protonation is less extensive. Interestingy, addition of copper(II)nitrate also suppresses the elimination reaction to a significant extent. Unfortunately, elimination is still faster than the Diels-Alder reaction on the internal double bond of 4.44. 

The desired pyridylamine was obtained in 69 % overall yield by monomethylation of 2-(aminomethyl)pyridine following a literature procedure (Scheme 4.14). First amine 4.48 was converted into formamide 4.49, through reaction with the in situ prepared mixed anhydride of acetic acid and formic acid. Reduction of 4.49 with borane dimethyl sulfide complex produced diamine 4.50. This compound could be used successfully in the Mannich reaction with 4.39, affording crude 4.51 in 92 % yield (Scheme 4.15). Analogous to 4.44, 4.51 also coordinates to copper(II) in water, as indicated by a shift of the UV-absorption maximum from 296 nm to 308 nm. 

In the flask were placed 60 g of powdered paraformaldehyde, 100 ml of dioxane and 3 g of copper(II) acetate and 0.3 mol of liquid dimethylamine was added at -20 C. The temperature was allowed to rise gradually to 40-45°C with occasional cooling and when the reaction had subsided, the mixture was cooled to 20°C and a second portion of 0.3 mol of the amine was added. When this had reacted, the remainder of the 2.0 mol of dimethylamine was added in the same way. The mixture... 

Irradiation of 3,5-disubstituted isoxazoles in alcoholic solvents gave reaction products such as acetals incorporating the reaction solvent. The use of triethylamine in acetonitrile media produced ketene-aminals by reductive ring cleavage. The reductive ring cleavage product was also obtained by irradiation of the isoxazole in alcohol in the presence of copper(II) salts (Scheme 3) (76JCS(P1)783). 

In contradistinction to this, weak ferromagnetism has been observed in a number of chloro and bromo complexes of the type M2[CrX4] (M = a variety of protonated amines and alkali metal cations, X = Cl, Br), which are analogous to previously known copper(II) complexes (p. 1192). They have magnetic moments at room temperature in the region of 6BM (compared... 

Gel breakers may also act according to a redox reaction. Copper (II) ions and amines can degrade various polysaccharides [1621]. 

Partial hydrolysis of a potentially heptadentate Schiff-base tripodal ligand derived from tris-(2-aminoethyl)amine and 2-hydroxyacetophenone, induced by copper(II) salts, was reported and the final copper(II) complex (377) was characterized.333 Using salicylaldehyde as a co-ligand, with a copper(II) complex (378), catalytic epoxidation was demonstrated 334... 

A list of structurally characterized copper(I) complexes of tripodal aliphatic amines is provided in Table 4 (cf. Section 6.6.3.1.1 for corresponding mononuclear or dinuclear copper(II) complexes). Copper(II) complexes [(L)CuCl]Cl (664) and [(L)Cu(MeCN)][C104]2 (665) with the ligand that is present in complex (662) were also structurally characterized.522... 

Copper(l) analogues [(L)Cu(MeCN)][CF3S03] (747) [yellow, four-coordinate (two amine donors, one of the two pyridinyl groups and an MeCN] and [(L)Cu(MeCN)][BF4] (748) [red, five-coordinate (two tertiary amine, two pyridinyl and an MeCN] [L as that in copper(II) complex (241)] were structurally characterized and redox properties of these complexes were also investigated.224... 

---