Copper 2-ethylhexanoate

An oxidative heterocoupling reaction between indoles and ketones was reported that provided a facile route into a-indolylketones <04JA7450>. Treatment of indole and carvone 194 with lithium hexamethyidisilazane (LiHMDS) and the oxidant, copper 2-ethylhexanoate, produced 3-substituted indole 195. The latter was converted into hapalindole Q 196. 

Copper-II-ethylhexanoate Cu2- 0 Metal organic compound Non-volatile, solid Not stable during recycling... 

Styrene (St) (Aldrich, 99%) was used as received and /-butyl aciylate (/BA) (Aldrich, 99%) was passed through a column filled with basic alumina. Tris(2-dimethylaminoethyl)amine (MceTREN, 99 %) and tris(2-pyridylmethyl)amine (TPMA, 99 %) are commercially available from ATRP Solutions Inc (www.atrpsolutions.com). ATHPpare resin (ATRP Solutions Inc.), diethyl 2-bromo-2-methylmalonate (DEBMM) (Aldrich, 98%), copper(ll) bromide (Aldrich, 99%), tin(ll) 2-ethylhexanoate (Sn(EH)2) (Aldrich, 95%), N,N-dimethylformamide (DMF) (Aldrich, 99%), methylene chloride (Fisher Scientific), trifluoroacetic acid (TFA) (Aldrich, 99%) and 2,2 -azo-bis(isobutyronitrile) (AIBN) (Aldrich, 99%) were used as received. Fc203 particles (size < 50 nm) were purchased form Aldrich. 

The extraction of transition metals with this mixture is much more efficient than that of alkaline earth salts. These metal salts can be extracted from dilute aqueous solutions, with concentrations as low as 0.01 M. An example of such an extraction is illustrated in Fig. 6, where a dilute copper chloride solution is extracted by (1) a strong base liquid anion exchanger (trioctylamine HCl) and (2) a mixture of trioctylamine (TOA) and 2-ethylhexanoic acid, both extractions being carried out as a function of chloride concentration. 

Figure 6 Extraction of copper chloride as a function of free chloride concentration. Extractant composition (A) 0.5 M TOA + 0.5 M 2-ethylhexanoic acid in toluene (o) 0.5 M TOA HCl in toluene.

Figure 15 Osmometric vapor pressure measurements of (a) trioctylamine (b) an equimolar mixture of trioctylamine and 2-ethylhexanoic acid (c) copper chloride solubilized in the mixture (b).

The third spectrum (c) was obtained from copper chloride dissolved in hydrated trioctylammonium 2-ethylhexanoate in toluene (the mixed extractant). It has a broad maximum absorbance at 725 nm, its symmetry is similar to that of copper carboxylate, and bonding of copper can be assumed to occur via the carboxylic oxygens in a manner similar to that of the dimer. Spectrum (c) bears an even greater similarity to that of the Cu-EDTA complex, the maximum absorption being at 734 nm, and which is known to have a distorted octahedral structure [12]. It is easy to convert the carboxyT ate dimer into a mixed complex. On adding trioctylamine to copper carboxylate, the maximum absorption shifts gradually from 680 to 725 nm. It is assumed that the addition of the amine converts the dimer into a monomer in which copper is bound to four monomeric carboxylic ligands and two amine molecules are located farther away in an axial position. It is of interest to note that the anion of the salt coextracted with the metal ion has no effect on the visible spectrum i.e., it is immaterial whether copper fluoride, chloride, or nitrate is extracted they all have the same spectrum. 

Figure 17 Low-frequency IR spectra (a) TO A -I- 2-ethylhexanoic acid (0.05 M of each in CCU) (b) mixture (a) loaded with copper chloride.

Cobalt, Cobalt acetate (ous) Cobalt linoleate (ous) Cobalt naphthenate (ous) Cobalt octoate. Cobalt sulfate (ous) Cobalt tallate Copper linoleate Copper naphthenate. Copper octoate. Copper tallate Erucic acid, 2-Ethylhexolc add. Iron linoleate Iron naphthenate. Iron octoate Iron tallate Lead linoleate Lead naphthenate. Lead octoate. Lead tallate. Lithium drier Magnesium stearate Manganese acetate (ous) Manganese linoleate Manganese naphthenate Manganese octoate Manganese tallate. Menhaden oit Naphthenic add. Nickel octoate Nuact NOPB Prifrac 2990 Rosin-, Sorbitan tallate Strontium drier. Zinc 2-ethylhexanoate Zinc naphthenate Zinc tallate. Zirconium octoate... 

Soap, metaiiic n. Any product derived by reacting a fatty acid with a metal. Metallic soaps are widely used as stabilizers for plastics. The fatty acids commonly used are lauric, stearic, ricinoleic, naphthenic, octanoic (2-ethylhexanoic), rosin, and tall oil. Typical metals are aluminum, barium, calcium, cadmium, copper, iron, lead, magnesium, tin, and zinc. 

Richardson [334] also examined the decomposition of tert-hntyl hydroperoxide in the presence of copper(II) 2-ethylhexanoate in chlorobenzene at 50 C. The product composition was approximately 87% cr/-butyl alcohol, 11% di-r-butyl-peroxide, 1-2% acetone and a large amount of oxygen. Reaction is 0.55 order in copper salt and less than first order dependence on hydroperoxide was observed. Trapping experiments with 2,6-di-r-butyl-p-cresol indicate a radical mechanism. The kinetic data indicate a mechanism involving a hydroperoxide complex, [Cu(II)2(ROOH)2], and NMR spectral evidence was obtained for axial hydroperoxide ligands [334]. 

Building on earlier work with stoichiometric amounts of copper salts, Chem-ler devised conditions for an intra-/intermolecular diamination of N-mesyl 2-allylanilines 151 in combination with different sulfamides as reaction partners for the second C-N bond formation to give 152 (Scheme 16.40). Again, using a Bisox ligand instead of the achiral eh [eh = 2-ethylhexanoate] under in situ... 

The interesting step in a formal synthesis of (+)-monomorine I (1562) by Paderes and Chemler was the aminohydroxylation of the known (R)-alke-nylsulfonamide (+)-1642 with copper(II) 2-ethylhexanoate as the catalyst and TEMPO as the oxygen source (Scheme 208). When the reaction was performed in xylenes at 130 °C in a pressure tube, the 2,5-disubstituted pyrrolidine (+)-1643 was formed in 94% yield, and with a diastereoselectiv-ity of better than 20 1. Oxidation of1643 with w-CPBA produced the same aldehyde (+)-1610 that Backvall and his team had previously converted into (+)-monomorine (cf. Scheme 203). 

Scheme 208 Formal synthesis of (+)-monomorine I (1562) by Paderes and Chemler. Reagents and conditions (a) copper(ll) 2-ethylhexanoate (1.5 equiv.), TEMPO (3 equiv.), CS2CO3 (1 equiv.), xylenes (0.1 M), 130 °C (pressure tube), 24 h (b) m-CPBA, CH2CI2, 0 °C, 2 h.

Taylor and coworkers report a copper(II) 2-ethylhexanoate catalyst for the synthesis of oxindoles, thio-oxindoles, 3,4-dihydro-l//-quinolin-2-ones, and 1,2,3,4-tetrahydroquinolines from linear precursors by direct C(sp )-H and Ar-H coupling using atmospheric oxygen as the oxidant (Scheme 8.91). The reaction procedure is open to the air and easy to handle [162]. 

Coprecipitation of yttrium, copper and barium is most often done with carboxy-lates (citrates, oxalates, acetates) from solutions of nitrates. Control of the pH, temperature and concentration make the precipitation as quantitative as possible in order to preserve the stoichiometry of the mixture [126-129]. Long-chain carboxy-lates (2-ethylhexanoate, neodecanoate) ensure the solubility of metals in volatile solvents such as xylene or xylene-pyridine mixtures, in order to make drying at... 

Reduction involving Sn(ll) can be carried out in organic solvents. Lockhart and Haitko have reported the formation of aliphatic and aromatic copper(I) carboxylates by treatment of copperflD carboxylates, Cu(02CR>2, (R = Me, Ph, C17H35), with tin(ll) 2-ethylhexanoate in dichloromethane, Eq. 9.32 ... 

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