BF3 catalyst

The carhonylation reaction of toluene with carhon monoxide in the presence of HF/BF3 catalyst produces p-tolualdehyde. A high yield results (96% based on toluene and 98% based on CO). p-Tolualdehyde could be further oxidized to terephthalic acid, an important monomer for polyesters ... 

Fig. 6.6. Relative energies of four possible transition structures for Diels-Alder reaction of 1,3-butadiene and propenal, with and without BF3 catalyst. Geometric parameters of the most stable transition structures (.endo-cis) are shown. Adapted from J. Am. Chem. Soc., 120, 2415 (1998), by permission of the American Chemical Society.

A gas-phase alkylation over an alumina-supported BF3 catalyst developed by UOP (Alkar process)312,313 reduces the corrosion problems associated with liquid-phase alkylation processes. An advantage of this technology is that it utilizes very dilute (8-10%) ethylene streams, such as refinery fuel gases (cracked gas streams). At the same time, to properly support BF3 is difficult. 

Solution polymerization of refinery C4 streams in the presence of AICI3 or BF3 catalyst yields liquid polymers called polybutenes. Because of the large difference in stability of tertiary and secondary carbocations involved, isobutylene cannot be effectively copolymerized with butenes. As a result, the majority of the product formed is polyisobutylene. 

The catalytic activity of these supported BF3 samples was tested using the reaction of 1-octene with phenol (performed at 85°C using 0.05 M of each reactant, in 100 ml of 1,2 dichlorethane with lg of supported BF3 catalyst). Table 2 shows the phenol conversion and selectivities towards octyl-phenyl ether obtained after 23 hours reaction time. It is clear that the activity of the BF3(H20)2/SiC>2 catalyst prepared in ethanol is superior to the other samples. The activity can thus be correlated with the number and strength of Bronsted acid sites identified on these catalysts using TGIR. 

Polymerization of 1,3-trioxane, a cyclic trimer of formaldehyde, is catalyzed by H3PM012O40 (177). The polymerization is very fast at concentrations of H3PM012O40 as low as 10-6 mol dm-3. To obtain comparable rates using BF3 catalyst, a BF3 concentration of 10 3 mol m 3 is required. 

In order to investigate the mechanism of the Staudinger reactions studied experimentally, the energy profiles for the formation of the cis and trans (3-lactams were calculated. Theoretical results suggested that the reaction would proceed most favorably with the BF3 catalyst coordinated to the ketene. 

Although boron trifluoride has been known for a long time as a catalyst for alkylation reactions, it did not become commercially important until larger quantities of aromatic alkylates were required by industry as raw materials for synthetic fibers, rubber, and plastics. As the petrochemical industry finds new uses for these aromatic alkylates, the use of BF3 catalyst is expected to expand greatly. Cumene, diispropylbenzene, and ethylbenzene are among the important alkylates which can be produced by this catalyst. 

Wilson, K. and Clark, J.H. (1998) Synthesis of a novel supported solid add BF3 catalyst Chem. Commun., 2135. 

Our initial investigation included a study of the alkylation of p-cresol with propylene oligomers and with various a-olefins. Because all alkylations were carried out by a well-known procedure and neither novel reactions nor unexpected results were encountered, no detailed experimental work will be reported As shown by the following reaction, all alkylations were carried out using BF3 catalyst at 80°-90°C. and excess olefin as the reaction solvent. 

Pentafluorosulfanyliminodifluorosulfane, SF5N=SF2, was synthesized in 1965 from the fluorination of S4N4 243) and also from the reaction of SF4 and NSF3 using a BF3 catalyst 184). However, the best yields of SF5N=SF2 are obtained from the reaction of SF5NH2 with SF4 in the presence of anhydrous hydrofluoric acid 183). It is a clear, colorless liquid that boils at 38°C. The chemical shifts of the fluorine resonances in the 19F NMR spectrum in various solvents and the effect of the solvent polarity on the chemical shifts are described 244). It is not easily hydrolyzed by water at room temperature however, alkaline hydrolysis is facile 184). 

Preliminary experiments were performed using Amberlyst-15 resin/BF3 catalyst to explore the stoichiometric requirements necessary to obtain a good alkylation catalyst. As the results in Table II show, BF3 alone, Amberlyst-15 alone and Amberlyst-15/BF3 catalyst with a 1 1 equivalent ratio of BF3 to -SO3H groups in the resin are not effective alkylation catalysts. However, in the presence of a large excess of BF3 (BF3/ -SO3H > 2 equivalent/equivalent), the catalyst is active for alkylation as indicated by the Cs" " yield being equal to 1.92 g C5+/g C4- converted (Run 4, Table II), or 1,95 g Cs+/g 04 converted (Run 6, Table II). 

Also shown in Table II is the effect of olefin space velocity. Comparison of Runs 4 and 6 shows that the Amberlyst-I5/BF3 catalyst can alkylate isobutane with butene in good yield at an olefin WHSV of 2.6 g olefin/g resin-hour. The alkylate yields are slightly lower than the theoretical value of 2,04 due to removal of some of the reactor contents via the on-line sampling system. The yields shown are based on the liquid... 

A similar situation was obtained with resin/BF3 catalyst, as shown below (conditions Amberlyst-I5/BF3 and 40 C) ... 

For resin/BF3 catalyst, the above process variables also affect alkylate quality. However, with the resin/ BF3 catalyst, the surface area of resin in addition to the functional group of the resin, may also play an important role in directing alkylation. Some results illustrating the effect of the resin s surface area on alkylate quality are shown in Table III. clearly, increasing the resin s surface area improves the alkylate quality both in terms of the fraction of trimethyl-pentanes in the C5+ alkylate and the clear research octane number (RON) of the C5+ alkylate. 

Since the Amberlyst XN-IOIO/BF3 catalyst produced an alkylate with quality superior to the other resins tested, additional work was performed with this resin/ BF3 catalyst to explore the effects of particle size and temperature, and sensitivity to olefin type. Olefin space velocity was kept at 2.6 grams C4=/gram resin-hour for all the results reported below. 

B. Effect of Olefin Feedstock. Different butenes were used as feedstocks to determine if the Amberlyst XN-IOIO/BF3 catalyst discriminates among them. The results are shown below (40 C, 1-04/04= =5.1 and 100% olefin conversion) ... 

C. Effect of Temperature. The effect of temperature on isobutane/trans-2-butene alkylation over Amberlyst XN-IOIO/BF3 catalyst was studied at 0 , 20 , 40 , euad 60 C. 73ie results are summarized below (i-C /c = 5.1 eund 1009 olefin conversion) ... 

Among the resins tested, the Amberlyst XN-IOIO/BF3 catalyst system appeared to be the most selective one, producing the best alkylate quality. This catalyst showed much less difference among different butene feedstocks than conventional HF and H2SO4 alkylation catalysts. In addition, its alkylate quality was improved as the temperature was decreased, reaching a plateau at about 0°C at which an alkylate with a R( I clear of... 

Some alkene monomers can be polymerized by a cationic initiator, as well as by a radical initiator. Cationic polymerization occurs by a chain-reaction pathway and requires the use of a strong protic or Lewis acid catalyst. The chain-carrying step is the electrophilic addition of a carbocation intermediate to the carbon-carbon double bond of another monomer unit. Not surprisingly, cationic polymerization is most effective when a stable, tertiary carbocation intermediate is involved. Thus, the most common commercial use of cationic polymerization is for the preparation of polyisobutylene by treatment of isobutylene (2-mcthylpropene) with BF3 catalyst at -80 C. The product is used in the manufacture of inner tubes for truck and bicycle tires. 

Hydrocarboxylation of the Ce-Cs a-olefins with cobaltcarbonyl/pyridine catalysts at 200 °C and 20 MPa gives predominantly the linear carboxylic acids. The acids and their esters are used as additives for lubricants. The Ce-Cio a-olefins are hydroformylated to odd-numbered linear primary alcohols, which are converted to polyvinylchloride (PVC) plasticizers with phthalic anhydride. Oligomerization of (preferably) 1 -decene, applying BF3 catalysts, gives oligomers used as synthetic lubricants known as poly-a-olefins (PAO) or synthetic hydrocarbons (SHC) [11, 12]. The C10-C12 a-olefins can be epoxidized by peracids this opens up a route to bifunctional derivatives or ethoxylates as nonionic surfactants [13]. 

A mono-[Pg.416]

Using BF3 catalyst, these authors have found a large proportion of cycles in all three systems (up to 40 % with NGE), which decreased with an increase of [THF. In the linear polymer a significant amount of double bonds was detected. 

This type of cyclization can be further improved by use of a BF3 catalyst. ... 

Commercial production of PAO using a BF3 catalyst generally involves a multi-stage, continuous stirred tank reactor (CSTR) process . In early production technology, the catalyst was destroyed with diluted aqueous alkali after polymerization. More recent patents disclosed improved processes using BF3 catalyst recycle to reduce catalyst usage, minimize process waste and improve process economics. ... 

The direct carbonylation of toluene into p-tolualdehyde has received much attention. Good results have been obtained using HF/BF3 catalysts under low pressure [139]. 

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