Stannic chloride as catalyst

A telomerization reaction of isoprene can be carried out by treatment with 2-chloro-3-pentene, prepared by the addition of dry HCl to 1,3-pentadiene (67). An equimolar amount of isoprene in dichi oromethane reacts with the 2-chloro-3-pentene at 10°C with stannic chloride as catalyst. l-Chloro-3,5-dimethyl-2,6-octadiene is obtained in 80% yield by 1,4-addition. 

With stannic chloride as catalyst apparently no co-catalyst is required [64], and the initiation reaction was represented thus ... 

Water has also been shown to be essential for the liquid phase polymerization of isobutylene with stannic chloride as catalyst (Norrish and Russell, 87). The rates of reaction were measured by a dilatometric method using ethyl chloride as common solvent at —78.5°. With a mixture consisting of 1.15% stannic chloride, 20 % isobutylene, and 78.8% ethyl chloride, the rate of polymerization was directly proportional to the amount of added water (up to 0.43% of which was added). A rapid increase in the rate of polymerization occurred as the stannic chloride concentration was increased from 0.1 to 1.25% with higher concentrations the rate increased only gradually. It was concluded that a soluble hydrate is formed and functions as the active catalyst. The minimum concentration of stannic chloride below which no polymerization occurred was somewhat less than half the percentage of added water. When the concentration of the metal chloride was less than about one-fifth that of the added water, a light solid precipitated formation of this insoluble hydrate which had no catalytic activity probably explains the minimum catalyst concentration. The addition of 0.3% each of ethyl alcohol, butyl alcohol, diethyl ether, or acetone in the presence of 0.18% water reduced the rate to less than one-fifth of its normal value. On the other hand, no polymerization occurred on the addition of 0.3 % of these substances in the absence of added water. The water-promoted reaction was halved when 1- and 2-butene were present in concentrations of 2 and 6%, respectively. 

Lemieux and Brice33 have studied the rearrangement under the conditions employed by Pacsu,80 involving the use of stannic chloride as catalyst, with pure chloroform as solvent. The reaction was shown to be specific for the anomeric center, and the following observations appear to establish definitely the main features of the mechanism for this reaction. A quantitative yield of silver chloride was obtained on treating silver acetate with an excess of stannic chloride in chloroform, and it seemed probable that there results a chloroform solution of stannic chloride and stannic trichloride acetate (LVIII). The solution was able to catalyze the anomerization. 

Note In a recent paper the solvent used for the condensation of 293 and 294 with stannic chloride as catalyst was changed from 1,2-dichloromethane to nitromethane. This improved the yield of the anomeric mixture 295 and 296 by at least 22% (93JHC509). 

The electrophilic character of aliphatic nitroolefins and the synthetic equivalency of nitro and carbonyl groups have been exploited in a recently developed regiospecific route to bicyclo[3.3.0]octenones (Scheme 12).63 With stannic chloride as catalyst,... 

C-Glycosylation in the D-ribofuranose series can be effected under very mild conditions in the presence of stannic chloride as the catalyst, but the product may consist of anomeric mixtures. Thus, 2-j3-D-ribofuranosylnaphthalene (202), 2,4,6-trimethoxy-1-/3-D-... 

SNR was prepared by direct chloromethylation of PDS. Chloromethylation of PDS was successfully performed in chloromethylmethylether solution using stannic chloride as a catalyst. The PDS obtained from Petrarch Systems was terminated with OH groups at the end of siloxane chain. A typical... 

Stannic chloride has been attached to monomers 21 containing ester (21a), carbazole (21b), pyrrolidone (21c), nitrile (21d) and pyridine (21d) moieties. The polymeric ligands were prepared by copolymerization of styrene, divinylbenzene and functional monomers such as methyl methacrylate, A -vinylcarbazole, Af-vinylpyrrolidone, acrylonitrile and 4-vinylpyridine [33], These polymers were treated with stannic chloride in chloroform to afford the corresponding polymer-supported stannic chloride complexes (Eq. 8). These polymeric complexes have been used as catalysts for such organic reactions including esterification, acetalization, and ketal formation. These complexes had good catalytic activity in the reactions and could be reused many times without loss of activity. Their stability was much better than that of plain polystyrene-stannic chloride complex catalyst. 

This reaction has also been conducted with stannic chloride as the catalyst. ... 

The ability to predict the regioselectivity of Diels-Alder reactions is a cornerstone of their use in synthesis. Methyl vinyl ketone, for example, reacted with 2-methyl-1,3-butadiene to give a 3 1 mixture of 69 and 70. Gutsche et al. used the para product (69) to synthesize a-bisabalol. They also reported that using stannic chloride as a catalyst (sec. 11.6.A) increased the ratio of 69/70 to 93 7. ... 

The copolymerization reaction is free radical in nature and is catalyzed by such initiators as peroxides [10], oxygen, azo compounds [11,11a], and light [9a, 12]. Styrene dissolved in liquid sulfur dioxide and catalyzed by stannic chloride (cationic catalyst) gives only polystyrene whereas the use of azo-bisisobutyronitrile gives poly(styrene sulfone). 

The cationic copolymerization was carried out in air at 25°C in a nitrobenzene solution using stannic bromide as catalyst, while the anionic polymerization was studied in air with sodium dissolved in anunonia [186]. Although many monomers may be polymerized by quaternary ammonium salts, vinyl acetate does not produce any polymer on treatment with dimethylphenylbenzylammonium chloride [187]. 

CAMEO failed to predict the formation of 2-benzoylthiophene (12) via Friedel-Crafts acylation of thiophene (13) with benzoyl chloride (14) in the presence of a Lewis acid (e.g., stannic chloride) using the Electrophilic Aromatic module. Thiophene is highly reactive under these conditions and would have been expected to undergo acylation readily, as previously reported (71) (Scheme 4). Instead, CAMEO predicted that stannic chloride (the catalyst) would replace a hydrogen in either the 2- or 3-position of... 

Coumarone-indene resin n. Any of a family of resins produced by polymerizing a coal-tar naphtha containing coumarone and indene. The naphtha is first washed with sulfuric acid to remove some impurities, then is polymerized in the presence of sulfuric acid or stannic chloride as a catalyst. Remaining impurities determine the quality of the resin, which can range from a clear, viscous liquid to a dark, brittle solid. Coumarone-indene resins have no commercial applications when used alone. 

Resorcinol in particular has attracted a lot of attention. It was seen earlier that Webster and Kamstra isolated a product and identified it as a malein 146 on reaction of resorcinol with MA in the presence of a stannic chloride (anhydrous) catalyst. Other workers have employed various conditions and catalysts. For example, Graff et claim that the same product is obtained... 

Stannic chloride is also used widely as a catalyst in Eriedel-Crafts acylation, alkylation and cycHzation reactions, esterifications, halogenations, and curing and other polymerization reactions. Minor uses are as a stabilizer for colors in soap (19), as a mordant in the dyeing of silks, in the manufacture of blueprint and other sensitized paper, and as an antistatic agent for synthetic fibers (see Dyes, application and evaluation Antistatic agents). 

A typical cationic polymeriza tion is conducted with highly purified monomer free of moisture and residual alcohol, both of which act as inhibitors, in a suitably dry unreactive solvent such as toluene with a Eriedel-Crafts catalyst, eg, boron triduoride, aluminum trichloride, and stannic chloride. Usually low temperatures (—40 to —70°C) are favored in order to prevent chain-transfer or sidereactions. 

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