Palladium tetrafluoroborate

A, Dimethyl (s)-2-hexenedioate. A 100-roL, one-necked, round-bottomed flask is capped by a septum, swept with dry nitrogen and flame-dried. The flask is charged with methyl acrylate (50 ml, 0.55 mol. Note 1), then anhydrous lithium tetrafluoroborate (9 g, 0.096 mol, Note 2), and finally tetrakis(acetonitrile)palladium tetrafluoroborate (1.33 g, 0.003 mmol. Note 3). The mixture is stirred briefly until homogeneous. It is warmed under nitrogen in a 40°C-o11 bath for 72 hr (Note 4) and then allowed to cool to room temperature. The mixture is added to saturated aqueous sodium bicarbonate (100 mt) and extracted with ether (3 x 50 mt). The combined ether extracts are dried over anhydrous magnesium sulfate, filtered and concentrated to an oil with a rotary evaporator. The residue is distilled through a lO-cm... 

Propano1, titanium (4+) salt (546-68-9), 65, 230 Tetrakis(acetonitrile)palladium tetrafluoroborate (21797-13-7),... 

Several catalyst systems have been described for the tail-to-tail dimerization of methyl acrylate.7 -7 Advantages of the dimerization procedure described here are its mild conditions, efficient use of the catalyst, and high selectivity for the b isomer. Tetrakis(aceto-nitnle)palladium tetrafluoroborate, Pd (NCMe)4(BF )2, also efficiently catalyzes dimerization of ethyl acrylate and methyl methacrylate. The presence of lithium tetrafluoroborate in the reaction mixture increases the rate of the reaction and prolongs catalyst life. Dimerization of methyl acrylate can be effected without lithium tetrafluoroborate if the reaction is performed in mtromethane. 

Methyl acrylate 2-Propenoic acid, methyl ester (9) (96-33-3) Tetrakis(acetomtrile)palladium tetrafluoroborate Palladium(2+), tetrakis(acetonitrile)-, bis[tetrafluoroborate (1-)] (8,9), (21797-13-7)... 

Several examples of the cyclization of indole derivatives with alkenic side chains in the 3-position have been reported.6 In these examples, palladium chloride in combination with silver tetrafluoroborate is the cyclizing agent. The palladium tetrafluoroborate, presumably formed, should be a very reactive palladating species and probably is the reason why these reactions proceed at room temperature, although the mechanism is not yet completely clear. These reactions were worked up reductively (by addition of sodium borohydride) in order to reduce the expected alkenic product or any relatively stable organopalladium complexes that may have been formed (equation 4).6... 

During the following 15 years, only small advances were achieved in increasing catalyst efficiencies. Independently, Fenton [9a] at Union Oil and Nozaki [9b] at Shell Development Company (USA) discovered several related palladium chlorides, palladium cyanides, and zero-valent palladium complexes as catalysts. Sen and co-workers [10] reported that cationic bis(triphenyl-phosphine)-palladium tetrafluoroborate complexes in aprotic solvents such as dichloromethane, produced ethylene/carbon monoxide copolymers under very mild conditions. The reaction rates were, however, very low, as were the molecular weights. 

An active and selective catalyst proved to be ( / -methallyl) (77 -cycloocta-l,5-diene)palladium tetrafluoroborate activated by a phosphorus ligand. It can be seen from Table V that the nature of the phosphorus ligand and the P Pd ratio strongly affect catalytic activity and product selectivity. The best results are observed for tributylphosphine and a P Pd ratio of 0.5 1 to 1 1. Noteworthy is the inhibition of the reaction for P Pd ratio of 2 or more. The main dimer obtained is dimethyl raAW-hex-2-enedioate when tributylphosphine was used. In this instance, practically no change in selectivity is observed by varying the P Pd ratio. Lower selectivities are observed for less basic phosphorus ligands such as triphenylphosphine or -phosphite. 

In none of the above cases has a reaction been performed whilst taking the EXAFS data. Hamill et al. [50] have investigated catalysis of the Heck reaction by palladium salts and complexes in room-temperature ionic liquids. On dissolution of palladium ethanoate in [BMIMj and N-butylpyridinium ([BP] ) hexafluorophos-phate and tetrafluoroborate ionic Hquids, and triethyl-hexyl ammonium bis(trifluo-romethanesulfonyl)imide, a gradual change from ethanoate coordination to the formation of palladium metal was observed in the Pd K-edge EXAFS, as shown in Figure 4.1-13. 

Nitroform, Methanol, Hydrazine Nitroform, Diethyl ether, Hydrazine Nitroform, Methyl acetate, SUver-I oxide, 1,4-Dibromobutyne-2, Chloroform Glyoxal, Benzylamine, Formic acid, Acetonitrile, Acetic anhydride. Palladium on charcoal, Bromobenzene, Chloroform, Sulfolane, Nitrosonium tetrafluoroborate. Ethyl acetate TNT, DMSO, Oxygen gas. Sodium benzoate. Hydrochloric acid. Methanol, Acetone... 

Palladium-catalyzed arylation of the electron-rich olefin bntyl vinyl ether has been accomplished in the ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate using as the arylating agents aryl iodides and bromides instead of the commonly used, but commercially unavailable and expensive, aryl triflates. The reaction proceeds with high efficiency and remarkable regioselectivity, leading almost exclnsively to substitution by various aryl groups at the olefinic carbon a to the heteroatom of butyl vinyl ether (Xu et ak, 2001). 

Synthesis of [(R)-lV,Af-Dimethyl(l-methyl)benzylaminato-C, N]- rac-4,4, 6,6 -tetramethyl-2,2 -bis[bis(3,5-dimethylphenyl)phosphino]-biphenyl -palladium(II) tetrafluoroborate and separation... 

The palladium complex was purchased from Strem Chemical Company and was used as received. Alternatively, material prepared from palladium sponge and mtrosomum tetrafluoroborate in acetonitrile worked equally well. 

Palladium, tetrakis(acetonitrile)-, tetrafluoroborate, 66, 52 Palladium, tetrakis(triphenylphosphine)- (14221-01-3),... 

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