CuCl catalyst

Addition of Hydrogen Cyanide. At one time the predominant commercial route to acrylonitrile was the addition of hydrogen cyanide to acetylene. The reaction can be conducted in the Hquid (CuCl catalyst) or gas phase (basic catalyst at 400 to 600°C). This route has been completely replaced by the ammoxidation of propylene (SOHIO process) (see Acrylonitrile). 

Vinyl chloride reacts with ammonium chloride [12125-02-9] and oxygen in the vapor phase at 325°C over a cupric chloride [7447-39-4] CuCl, catalyst to make 1,1,2-trichloroethane and ammonia (68). 

Percec and coworkers327 331 reported in situ fonnation of active CuCl/CuCL catalyst from the initiator, CinO, Cu(0) and combinations of these in conjunction with ligand (bpy) and various polyethers or ethylene glycol and suggested that improved control was obtained under these conditions. 

Haloalkynes (R—C=C—X) react with ArSnBu3 and Cul to give R—C= C—Ar. Acetylene reacts with two equivalents of iodobenzene, in the presence of a palladium catalyst and Cul, to give 1,2-diphenylethyne. 1-Trialkylsilyl alkynes react with 1-haloalkynes, in the presence of a CuCl catalyst, to give diynes and with aryl triflates to give 1-aryl alkynes. Alkynes couple with alkyl halides in the presence of Sml2/Sm. Alkynes react with hypervalent iodine compounds " and with reactive alkanes such as adamantane in the presence of AIBN. ... 

Preparation of highly active CuCl catalyst for the direct process of methylchlorosilane production... 

It is evident that a highly dispersed CuCl catalyst will combine better with silicon and the Cu will diffuse faster into the Si lattice in the subsequent reaction steps. However, most works on this aspect have focused on the post treatment of a ready-made catalyst, which is a complicated process using a large amount of energy. 

CuCl, especially in a single crystal form, is extensively used as an optical material for its special optical properties. Orel et al. [2] first proposed a new method to obtain CuCl particles by the reduction of Cu with ascorbic acid. Several dispersants were used in the reduction and monodispersed CuCl particles can be obtained by selecting the proper dispersant and reduction conditions. In this work, the above method was used to modify the traditional process of CuCl preparation, namely, by reducing the Cu " with sodium sulfite to obtain the highly active CuCl catalyst to be used in the direct process of methylchlorosilane synthesis. 

The activities of the different CuCl catalysts are illustrated in Fig. 2. It can be seen that all CuCl precipitates prepared with the addition of a dispersant show high activity. The activity of the CuCl prepared without any dispersant is here used as the standard activity. It is of interest that the highest activity, which is nearly twice the standard activity, was obtained... 

Product selectivities fiom the different CuCl catalysts are shown in Table 1. There is no visible detrimental effect on the selectivities due to the introduction of the dispersants during CuCl preparation. The best selectivity was obtained with the CuCl prepared with the addition of SDBS. Therefore, SDBS is recommended as a dispersing agent that can be used in practical production. 

The reactivity and product selectivity increase as dispersing agents were introduced. Simultaneously, a higher silicon conversion was also obtained. A higher silicon conversion will decrease the burden of waste disposal. Therefore, this study provides a convenient and economical way for the preparation of highly effective CuCl catalyst that can be used in practical production using the direct process. 

Highly active CuCl catalysts for the direct process of methylchlorosilane synthesis were prepared by reducing Cu with a sodium sulfite solution in the presence of dispersing agents. Several well-known dispersants, e.g. SDBS, were used in this study. When SDBS was used, a catalyst in the form of small flakes was obtained that gave the best performance in reactivity, product selectivity and silicon conversion. This provides a convenient way to prepare the CuCl catalyst for use in industrial production. 

The reaction of propargyl chloride 83 and trichlorosilane 84 showed two different regioselectivities depending on the choice of transition metal catalysts [88]. Whereas the Sn2 substitution proceeded to give the propargylsilane 85 with 94% selectivity using a CuCl catalyst, the silylallene 86 was obtained via an SN2 pathway with >97% selectivity with 3mol% of Ni(PhCOCHCOPh)2 (Scheme 3.42). 

A novel macrocyclic multinuclear acetyUde complex was prepared from o-diethyn -benzene with equimolar [PdCWPEtsli] in the presence of CuCl catalyst in EtzNH at 25 °C gave 21 in 33% yield<99AGIE174>. 

Higher alkenes can also be converted to methyl ketones with the Wacker catalyst, but the rates and selectivities are lower. Improved procedures use basic406,407 or alcoholic solvents 408 Tsuji and coworkers used the PdCl2/CuCl catalyst in DMF for the synthesis of a variety of natural products and fine chemicals.409 Only terminal alkenes are ketonized under these conditions, even when the substrate contains other functional groups.395... 

Figure I. Disappearance of phenols on oxidation of equimolar mixtures at 25°C pyridine-CuCl catalyst...

Table I. Relative Rates of Oxygen Absorption (Py-CuCl Catalyst 25°C)...

Another interesting aspect of the model reactions has been reported for copper-mediated processes.273 Thus, optically active methyl 2-bromopropionate was mixed with a CuCl catalyst, and the reaction was followed by NMR and polarimetry. The latter analysis showed, as in solvolysis, that the model quickly undergoes racemization i.e., the halogen on the chiral carbon dissociates and recouples. 

Pt(III) intermediates. The pressure dependence of the quantum yield for the reductive elimination of azide from [frans-Pt(CN) (N,)2] to give [Pt(CN) ] has been exeunined auid the results interpreted in terms of formation of a caged radical species via simultaneous scission of both Pt-N, bonds in the charge-treuisfer excited state. - Alcohols have been oxidised in a two electron process at room temperature by O2 in the presence of a H PtCl /CuCl catalyst. A cyclic process incorporating a Pt(III) species % ich undergoes a redox reaction with Cu(II) to regenerate the Pt(IV) catalyst appears to be involved. 14. Copper... 

There is only one example of the polyyne formation by an anodic reaction. Ohmura et al. [34] oxidized acetylene in dimethylformamide electrolyte solution containing CuCl catalyst ... 

Copper Catalysts When N-hydroxyphthalimide is used as an oxygen source, a range of substrates can be selectively oxygenated using PhI(OAc)2 as an oxidant in the presence of CuCl catalyst (Equation 11.26) [62]. When a radical trap, TEMPO (2,2,6,6-tetramethyl-l-piperidinyloxy), is added to the reaction mixture, a TEMPO-trapped compound can be isolated (21%) along with 23% of the desired product. Therefore, a radical intermediate is most likely involved in this transformation [63]. 

Cl is much stronger and there is lower possibility of halogen abstraction. We also sometimes observed a tiny amount of termination by recombination of growing radical in the ATRP of NIPAAm with CirBr at Ml conversion. This termination was not really detected on any SEC traces in the case of CuCl catalyst. Because, for the chain extension, we nsed a strategy of direct addition of a second monomer solntion, the first block has to be polymerized np to full conversion. Therefore to reduce these two different types of termination CuCl combined with MeeTREN was selected as catalyst system. 

The cross-coupling of a resin-bound iodobenzoic acid 76 with trimethylsilylacetylene followed by TBAF desilylation provides a polymer-supported arylacetylene. Treatment with an aldehyde and a secondary amine in dioxane in the presence of CuCl catalyst results in the generation of resin-bound propargylamines. The final products 77 are cleaved from the resin and obtained in excellent yields and purity (Scheme 30) " ... 

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