Boron trifluoride catalyst

DIELS-ALDER CATALYSTS Boron trifluoride. Boron irifluoride etherate. Ethylaluminum dichloride. Silica gel. Stannic chloride. Titanium(IV) chloride. Tris(p-bromophenyl)aminium hexa-chlorostibnatc. 

The five membered cydic 1,3-dioxolane (CHjOCHjCHjO) can be polymerised by a variety of catalysts including sulphuric acid (P7), perchloric acid (98), phosphorus pentachloride (PP) and alkyl aluminium compounds with water as a co-catalyst (100). The effect of the catalyst boron trifluoride diethyl etherate on the polymerisation of 1,3-dioxolane has also been studied and it has been found that equilibrium between monomeric 1,3-dioxolane and poly(l, 3-dioxolane) is set up in both the undiluted polymer and in solution (101-104). Controverf has arisen as to whether the equilibrium is between cyclic monomer and cyclic polymer (98) or between cyclic monomer and chain polymer (104). 

Type of reaction C-N and C-C bond formation Reaction conditions Dichlorometahne, room temperature Synthetic strategy One-pot Lewis acid mediated [3+3]-annulation Catalyst Boron trifluoride-etherate (BF3.0Et2)... 

Lithiated ynamides react stereoselectively with chiral A-sulfonyl imides without Lewis acid catalysts. Boron trifluoride etherate completely reverses the selectivity a switch (g) from a chelated to an open TS is proposed. 

The polymerization o oxetanes with cationic catalysts has been studied by many investigators. (1.H2) RoseC. ), in particular, first reported the homopolymerization of the parent compound, tri-methylene oxide (TMO), with a Lewis acid catalyst, boron trifluoride. The use of coordination catalysts to polymerize oxetanes has been reported in the patent literature by Vandenberg.W In this work, Vandenberg polymerized oxetanes with the aluminum trialkyl -water-acetylacetone coordination catalyst (referred to as chelate catalyst) that he discovered for epoxide polymerization . This paper describes the homo- and co-polymerization of TMO with these coordination catalysts. Specific TMO copolymers, particularly with unsaturated epoxides such as allyl glycidyl ether (AGE), are shown to provide the basis for a new family o polyether elastomers. These new elastomers are compared with the related propylene oxide-allyl glycidyl ether (PO-AGE) copolymer elastomers. The historical development and general characteristics of polyether elastomers and, in particular, the propylene oxide elastomers, are reviewed below. 

In each case the configuration around the boron changes from trigonal planar to tetrahedral on adduct formation. Because of this ability to form additional compounds, boron trifluoride is an important catalyst and is used in many organic reactions, notably polymerisation, esterification, and Friedel-Crafts acylation and alkylations. 

Other catalysts which may be used in the Friedel - Crafts alkylation reaction include ferric chloride, antimony pentachloride, zirconium tetrachloride, boron trifluoride, zinc chloride and hydrogen fluoride but these are generally not so effective in academic laboratories. The alkylating agents include alkyl halides, alcohols and olefines. 

This catalyst should really be purchased rather than made because its use in underground chemistry is limited and is hardly watched at all if not ever. This may change considering its potential as a precursor to the NaBHsCN in Strike s 1 method of choice. There are a lot of ways to make this catalyst, but the least involved is the one using boron trifluoride. What the method calls for is an apparatus called an autoclave. You know how using a vacuum causes the absence of pressure to make things boil at a lower temperature Well, an autoclave is a device that causes an... 

Boron trifluoride [7637-07-2] (trifluoroborane), BF, was first reported in 1809 by Gay-Lussac and Thenard (1) who prepared it by the reaction of boric acid and fluorspar at duU red heat. It is a colorless gas when dry, but fumes in the presence of moisture yielding a dense white smoke of irritating, pungent odor. It is widely used as an acid catalyst (2) for many types of organic reactions, especially for the production of polymer and petroleum (qv) products. The gas was first produced commercially in 1936 by the Harshaw Chemical Co. (see also Boron COMPOUNDS). 

Boron trifluoride catalyst is used under a great variety of conditions either alone in the gas phase or in the presence of many types of promoters. Many boron trifluoride coordination compounds are also used. 

Boron trifluoride catalyst may be recovered by distillation, chemical reactions, or a combination of these methods. Ammonia or amines are frequently added to the spent catalyst to form stable coordination compounds that can be separated from the reaction products. Subsequent treatment with sulfuric acid releases boron trifluoride. An organic compound may be added that forms an adduct more stable than that formed by the desired product and boron trifluoride. In another procedure, a fluoride is added to the reaction products to precipitate the boron trifluoride which is then released by heating. Selective solvents may also be employed in recovery procedures (see Catalysts,regeneration). 

Ben2enesulfonic anhydride has been claimed to be superior to ben2enesulfonyl chloride (140). Catalysts used besides aluminum chloride are ferric chloride, antimony pentachloride, aluminum bromide, and boron trifluoride (141). 

Aluminum bromide and chloride are equally active catalysts, whereas boron trifluoride is considerably less active probably because of its limited solubiUty in aromatic hydrocarbons. The perchloryl aromatics are interesting compounds but must be handled with care because of their explosive nature and sensitivity to mechanical shock and local overheating. 

Olefins are carbonylated in concentrated sulfuric acid at moderate temperatures (0—40°C) and low pressures with formic acid, which serves as the source of carbon monoxide (Koch-Haaf reaction) (187). Liquid hydrogen fluoride, preferably in the presence of boron trifluoride, is an equally good catalyst and solvent system (see Carboxylic acids). 

Cationic polymerization of coal-tar fractions has been commercially achieved through the use of strong protic acids, as well as various Lewis acids. Sulfuric acid was the first polymerization catalyst (11). More recent technology has focused on the Friedel-Crafts polymerization of coal fractions to yield resins with higher softening points and better color. Typical Lewis acid catalysts used in these processes are aluminum chloride, boron trifluoride, and various boron trifluoride complexes (12). Cmde feedstocks typically contain 25—75% reactive components and may be refined prior to polymerization (eg, acid or alkali treatment) to remove sulfur and other undesired components. Table 1 illustrates the typical components found in coal-tar fractions and their corresponding properties. 

Catalysts used in the polymerization of C-5 diolefins and olefins, and monovinyl aromatic monomers, foUow closely with the systems used in the synthesis of aHphatic resins. Typical catalyst systems are AlCl, AIBr., AlCl —HCl—o-xylene complexes and sludges obtained from the Friedel-Crafts alkylation of benzene. Boron trifluoride and its complexes, as weU as TiCl and SnCl, have been found to result in lower yields and higher oligomer content in C-5 and aromatic modified C-5 polymerizations. 

Dihydroxybenzophenones are used for the syntheses of dyes, polymers, and medicines. They are prepared by the condensation of resorcinol with benzoic acids. Catalysts used for this transformation are sulfonic resins (99), boron trifluoride (100), or zinc chloride in the presence of POCl (101). 

As a dibasic acid, malic acid forms the usual salts, esters, amides, and acyl chlorides. Monoesters can be prepared easily by refluxing malic acid, an alcohol, and boron trifluoride as a catalyst (9). With polyhydric alcohols and polycarboxyUc aromatic acids, malic acid yields alkyd polyester resins (10) (see Alcohols, polyhydric Alkyd resins). Complete esterification results from the reaction of the diester of maUc acid with an acid chloride, eg, acetyl or stearoyl chloride (11). 

Isopropylnaphthalenes can be prepared readily by the catalytic alkylation of naphthalene with propjiene. 2-lsopropylnaphthalene [2027-17-0] is an important intermediate used in the manufacture of 2-naphthol (see Naphthalenederivatives). The alkylation of naphthalene with propjiene, preferably in an inert solvent at 40—100°C with an aluminum chloride, hydrogen fluoride, or boron trifluoride—phosphoric acid catalyst, gives 90—95% wt % 2-isopropylnaphthalene however, a considerable amount of polyalkylate also is produced. Preferably, the propylation of naphthalene is carried out in the vapor phase in a continuous manner, over a phosphoric acid on kieselguhr catalyst under pressure at ca 220—250°C. The alkylate, which is low in di- and polyisopropylnaphthalenes, then is isomerized by recycling over the same catalyst at 240°C or by using aluminum chloride catalyst at 80°C. After distillation, a product containing >90 wt % 2-isopropylnaphthalene is obtained (47). 

Acid mixtures containing nitric acid and a strong acid, eg, sulfuric acid, perchloric acid, selenic acid, hydrofluoric acid, boron trifluoride, or an ion-exchange resin containing sulfonic acid groups, can be used as the nitrating feedstock for ionic nitrations. These strong acids are catalysts that result in the formation of nitronium ions, NO" 2- Sulfuric acid is almost always used industrially since it is both effective and relatively inexpensive. 

Toluene reacts with carbon monoxide and butene-1 under pressure in the presence of hydrogen fluoride and boron trifluoride to give 4-methyl-j iYbutyrophenone which is reduced to the carbinol and dehydrated to the olefin. The latter is cycHzed and dehydrogenated over a special alumina-supported catalyst to give pure 2,6- dim ethyl n aph th a1 en e, free from isomers. It is also possible to isomerize various dim ethyl n aph th a1 en es to the... 

Other THF polymerization processes that have been disclosed in papers and patents, but which do not appear to be in commercial use in the 1990s, include catalysis by boron trifluoride complexes in combination with other cocatalysts (241—245), modified montmorrillonite clay (246—248) or modified metal oxide composites (249), rare-earth catalysts (250), triflate salts (164), and sulfuric acid or Aiming sulfuric acid with cocatalysts (237,251—255). 

Catalysts. Nearly aU. of the industrially significant aromatic alkylation processes of the past have been carried out in the Hquid phase with unsupported acid catalysts. For example, AlCl HF have been used commercially for at least one of the benzene alkylation processes to produce ethylbenzene (104), cumene (105), and detergent alkylates (80). Exceptions to this historical trend have been the use of a supported boron trifluoride for the production of ethylbenzene and of a soHd phosphoric acid (SPA) catalyst for the production of cumene (59,106). 

The choice of catalyst is based primarily on economic effects and product purity requirements. More recentiy, the handling of waste associated with the choice of catalyst has become an important factor in the economic evaluation. Catalysts that produce less waste and more easily handled waste by-products are strongly preferred by alkylphenol producers. Some commonly used catalysts are sulfuric acid, boron trifluoride, aluminum phenoxide, methanesulfonic acid, toluene—xylene sulfonic acid, cationic-exchange resin, acidic clays, and modified zeoHtes. 

Other catalysts that can be used are boron trifluoride (5), copper—chromium oxides (6), phosphoric acid (7), and siUca-alurnina (8). Under similar conditions, ethanol yields /V-ethylaniline [103-69-5] and /V,/V-diethylaniline [91-66-7] (9,10). 

Diphenylamine can also be produced by passing the vapors of aniline over a catalyst such as alumina, or alumina impregnated with ammonium fluoride (17). The reaction is carried out at 480°C and about 700 kPa (7 atm). Conversion per pass, expressed as parts diphenylamine per 100 parts of reactor effluent, is low (18—22%), and the unconverted aniline must be recycled. Other catalysts disclosed for the vapor-phase process are alumina modified with boron trifluoride (18), and alumina activated with boric acid or boric anhydride (19). 

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