Carbon monoxide reaction with copper chloride

A solulion of CuCl in HCI absorbs carbon monoxide, forming copperil) carbonyl chloride. Cu(CO)Cl H 0. This reaction, which is used In gas analysis, is Indicative of the ability of copper to combine with carbon monoxide. Evidence for a true carbonyl is limited to the observation that if hot carbon monoxide is passed over hot copper, a metallic mirror is produced in the hotter parts of the tube. Other organometallic compounds include Ihe very unstable methyl copper, CHiCu. phenyl copper. C<,H5Cu, and bixchlurucopper acetylene CjHrtCuCIi . 

Dichlorotetracarbonyldirhodium has been obtained by the action of carbon monoxide at high temperature and pressure on a mixture of anhydrous rhodium(III) chloride and finely divided copper powder and by reaction of rhodium(III) chloride 3-hydrate with carbon monoxide saturated with methanol at moderate temperatures and atmospheric pressure. The preparation described here is a modification of the latter method, without use of methanol. This procedure is considerably simpler than the recently described preparation which involves adsorption of rhodium chloride on silica gel, chlorination, and subsequent carbonylation. ... 

Catalytic oxy-palladation is an extremely useful method for the synthesis of functionalized THF and tetrahydropyran moieties. This reaction is brought about simply by treating a 1,4- or 1,5-hydroxy alkene with 0.1 mol-eq of Pd(II) salts and copper(I) chloride in DMF, with oxygen (equation 181)655. If this reaction is carried out in the presence of carbon monoxide in methanol, then an ester moiety is introduced into the product molecule (equation 182)656-658. If an alkene is introduced in place of the CO, then a tandem vinylation reaction also takes place (equation 183)659. 

A mixture of 1.0 mmol of the 5-hydroxyalkene, 2.2 mmol of copper(I) chloride and 0.10 mmol of bis(ace-tonitrile)dichloropalladium in 3 mL of CH3OH under carbon monoxide (1.11 bar) is stirred at 23 °C until the reaction is complete (3.5 10 h, TLC monitoring). After removal of the methanol, the residue is triturated with pentane and the pentane solution is concentrated to give the crude organic products. Purification by short-path vacuum distillation provides the cyclization products. The stereochemistry is determined by an analysis of the H-NMR chemical shift of the hydrogen at C-5 this signal is 0.1 -0.2 ppm further downfield when the proton is cis to the ester side chain compared to the trans arrangement. 

Through an intramolecular alkoxycarbonylation reaction catalyzed by palladium(II), 4-pen-tenc-l,3-diols give tetrahydrofuro[3,2-6]furan-2(3f/)-ones. The reaction is carried out by treating the unsaturated diol with palladium(ll) chloride, copper(ll) chloride and sodium acetate under a carbon monoxide atmosphere. The yields are good and five-membered rings are exclusively obtained with total regioselectivity, as shown by the cyclization of. sj -3-hydroxy-melhyl-5-hexene-l,4-diol (1), which affords only one product in 60% yield44. 

Reaction of 2-allyl benzyl alcohols at 20 °C for 24 hours with a catalytic amount of palladium(II) chloride and copper(II) chloride in methanol under a carbon monoxide atmosphere gives the corresponding 3,4-dihydro-l//-2-benzopyran-3-acetates. ( )- and (Z)-2-(2-Butenyl)benzyl alcohol (1) give different isomers, 2A and 2B. the configuration of which is assigned on the basis of mechanistic considerations84. 

A useful extension of the alkoxycarbonylation reaction has been devised in order to obtain 3,4-dihydro-4-hydroxy-l//-2-benzopyran-3-acetic acid lactones from 5-alkene-l,4-diols. The intramolecular cyclization of 7, carried out with palladium(II) acetate and copper(II) chloride under a carbon monoxide atmosphere, affords the m-lactone 8 in 68% yield. The configuration is assigned on the basis of H-NMR double resonance methods86. 

The activation and functionalization of C-H bonds by the Pt" ion is particularly attractive because of the unusual regioselectivity, high oxidation level specificity, and mildness of reaction conditions. Moreover, Sen has recently reported that, in the presence of copper chloride at 120-160 °C, Shilov chemistry can be made catalytic with dioxygen as the ultimate oxidant [39]. A number of aliphatic acids were tested, and turnover numbers of up to 15/hour with respect to platinum were observed. H/D exchange studies also confirm the marked preference for the activation of primary C-H bonds in the presence of weaker secondary C-H bonds. This study constituted the first example of the direct use of dioxygen in the catalytic oxidation of unactivated primary C-H bonds under mild conditions that does not involve the use of a co-reductant (e. g., sacrificial metals, 2H + 2e", dihydrogen, or carbon monoxide see below). 

In the reactions of carbon monoxide with copper(II) chloride, nickel(II) chloride or silver(l) chloride, thermal decomposition of the salts to give dichlorine, followed by the... 

Simply changing the solvent in the Pd-based catalytic system from water to a mixture of water and a perfluorocarboxylic acid (some water was necessary for the reaction, see Scheme 4) had no significant effect on product composition formic acid was still the principal product from methane. However, the addition of copper (I) or (II) chloride to the reaction mixture had a dramatic effect. Methanol and its ester now became the preferred products, with virtually no acetic and little formic acid being formed [42b] The activation parameters for the overall reaction determined under the condition when the rate was first-order in both methane and carbon monoxide were A=2xl04 s 1 Ea=15.3 kcalmol-1. Since methyl trifluoroacetate is both volatile and easily hydrolyzed back to the acid and methanol, it should be possible to design a system where the acid is recycled and methanol is the end-product. 

The reaction is carried out in a Schlenk tube, Fig. 1. Acetone (10 mL) is cooled in an ice bath and saturated with carbon monoxide by passing in a brisk stream of the gas for 10 minutes. Potassium hydrotris(pyrazolato)borate (252 mg, 1.0 mmole) and copper(I) chloride (99 mg, 1 mmole) are added to the acetone, and the mixture is stirred for 30 minutes while continuing to pass a slow stream of carbon monoxide. At the end of this period, the white suspension is filtered, using the Schlenk-type apparatus illustrated, Fig. 2, keeping the whole under an atmosphere of CO. The clear colorless filtrate is evaporated to dryness, and the cream-colored residue is extracted with 10 mL light petroleum (boiling range 40-60°, saturated with CO) and filtered. Evaporation of the solvent from the filtrate affords a white powder of Cu(CO)[(pz)3BH] (156 mg, 51%). 

Similarly, alkenes react with carbon monoxide and methanol in the presence of palladium(II) chloride and a weak base (such as sodium acetate or butanoate) at 25 C and 3.03 bar of carbon monoxide pressure to form succinates. During this reaction palladium(O) is formed however, the reaction can be converted into a catalytic method if stoichiometric amounts of copper(II) chloride are added for reoxidation1 20. cis Addition is observed in the reaction of (E)- and (Z)-2-butene or 1-deuterated terminal alkenes19-22,39 as well as benzobicyclo[2.2.1]heptadienes40. In the absence of the base, methoxycarboxylation occurs (see Section 1.5.8.4.1.) as a trans processl9,20,22. 

Addition of dichloroketen to cyclohexenyl phenyl sulphoxide yields the ds-lactone (18). The methylbutanolide (19) is formed by the reaction of but-3-en-l-ol with carbon monoxide in the presence of palladium(II) chloride, copper(II) chloride, and triphenylphosphine. Palladium(0)-phosphine complexes catalyse the carboxylation of isopropylidenecyclopropane to give the furanone (20). ... 

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