Palladium chloride catalysts

Example 86 A 0.10 mole amount of the starting 3-(4-hydroxyphenyl) propylene, 0.25 mole of methyl nitrite, 0.5 liter of methyl alcohol, and 0.006 mole of a palladium chloride catalyst were charged into a reaction vessel. Then, the reaction was carried out at a temperature of 20.degree. C. for 1.5hours."... 

With a palladium chloride catalyst, butenediol is carbonylated by carbon monoxide, giving 3-hexenedioic acid [4436-74-2] C HgO (94). 

With palladium chloride catalyst, carbon monoxide, and an alcohol the labile hydroxyl is alkylated during carbonylation (199). 

Catalysis is done by an acidic solution of the stabilized reaction product of stannous chloride and palladium chloride. Catalyst absorption is typically 1—5 p-g Pd per square centimeter. Other precious metals can be used, but they are not as cost-effective. The exact chemical identity of this catalyst has been a matter of considerable scientific interest (19—21,23). It seems to be a stabilized coUoid, co-deposited on the plastic with excess tin. The industry trends have been to use higher activity catalysts at lower concentrations and higher temperatures. Typical usage is 40—150 ppm of palladium at 60°C maximum, and a 30—60-fold or more excess of stannous chloride. Catalyst variations occasionally used include alkaline and non-noble metal catalysts. 

In that complex, it may be that water reacts with the coordinated C2H4 to produce a cr-bonded CH2CH2OH group rather than an insertion reaction involving an OH group. The aldehyde is formed as H+ is lost, and the palladium is produced as shown in Eq. (22.31). The palladium chloride catalyst can be recovered (the price of palladium is almost 500/oz as this is written) by the reaction with CuCl2. 

The monomer/oligomer mixtures were used In the third step of the reaction sequence, the replacement of bromine with 2-methyl-3-butyn-2-ol by use of the bls(trlphenylphosphlne) palladium chloride catalyst system. This reaction used a trlethylamine/pyridine solvent system to replace the bromines on the ether sulfone with ethynyl groups protected by acetone adducts. The acetone protecting groups were then removed In a toluene/methanol/potasslum hydroxide solvent system. 

Smidt, J., Hafner, W., Jira, R., Sieber, R., Sedlmeier, J. and Sabel, A. (1962) The oxidation of olefins with palladium chloride catalysts. Angew. Chew. Int. Ed. 

The methyl nitrite then reacts with CO over a supported palladium chloride catalyst (at 100-120°Q to give the DMC product and to regenerate the NO (Equation 33) ... 

The oxidation of olefins to carbonyl compounds by means of palladium chloride catalysts (and involving intermediate organopalladium compounds) 22, 225, 226),... 

The first paper that demonstrated the feasibility of a palladium-catalyzed amination was a report by T. Migita and co-workers.6 They demonstrated that a tri-ortho-tolyl phosphine palladium chloride catalyst will catalyze the cross-coupling of N,N-diethylamino-tributyltin with bromobenzene. The process can be thought of as an amino-Stille cross-coupling. 

The ethylene-based version of the vinyl acetate process was also developed by Wacker Chemie. The process is similar to the Wacker process for acetaldehyde from ethylene which was developed about the same time. In the vinyl acetate process, ethylene is reacted with high purity oxygen and acetic acid in the presence of a palladium chloride catalyst. National Distillers and Chemicals, which later became USI chemicals and is now a division of Quantum Chemicals, developed a similar vapor phase ethylene-based technology in the United States. Both versions of the process are presently used commercially [25,26]. 

The ethylene-based process for vinyl acetate uses a palladium chloride catalyst for the oxidative addition of acetic acid to ethylene. The chemical reactions are as follows ... 

Palladium chloride catalyst, 181, 184 Palladium cupric-chloride catalyst, 158, 160 Partial condensation, 98, 101-103, 140 Partial oxidation (POX) ... 

The halopalladation of MCPs gives CP-Pd and CPC-Pd intermediates depending on the reaction conditions. Thus, the isomerization of alkylidene cyclopropyl ketones to 4ff-pyran derivatives takes place in the presence of a palladium chloride catalyst via chloropalladation to form a CPC-Pd and the successive P-carbon elimination (Eq. 10) [25]. In contrast, the addition of Nal changes the reaction pathway dramatically. Under the conditions, the reaction proceeds through a CP-Pd intermediate and results in the formation of furan derivatives. 

The acylation of arenes with alcohols has been shown to be possible using a palladium chloride catalyst in the presence of f-butylhydroperoxide. In 2-arylpyridines, substitution is directed to the ortho-position and, after initial paUadation, the formation of intermediate (59) is likely before reductive elimination yields the acylated product. The regioselective acetoxylation of indoles, at the 3-position, has been achieved using the palladium-catalysed reaction with phenyliodonium acetate. 3-Acyl indoles may also be prepared using acetyl chlorides with zirconium tetrachloride as a Lewis acid catalyst. 

Another path to hydrogen generation from ammonia works with magnesium hydride over homogeneous platinum and palladium chloride catalysts [103] ... 

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