Tosyl cellulose

Mesylated and Tosylated Celluloses. It has been estabUshed that the flame resistance of ceUulose (qv) is improved by oxidation of —CH2OH groups to —COOH (58—60). To correct some of the shortcomings of this treatment, mesyl or tosyl ceUulose was prepared and then the mesyl (CH2SO2) or tosyl (CH2CgH4S02) group was replaced with bromine or iodine (58—60) ... 

Thus polystyryl carbanions and polyacrylonitrile carbanions prepared by anionic polymerization were reacted with cellulose acetate or tosylated cellulose acetate in tetrahydrofuran under homogenous reaction conditions. The carbanions displaced the acetate groups or the tosylate groups in a S v2-type nucleophilic displacement reaction to give CA-g-PS and CA-g-PAN. Mild hydrolysis to remove the acetate/tosylate groups furnishes the pure cellulose-g-polystyrene (Figure 3). 

Figure 3. Grafting of polystyrylcarbanion onto tosylated cellulose acetate. Reprinted with permission from ref. 27. Copyright 1988 Humana Press.

A. Koschella and Th. Heinze, Unconventional cellulose products by fluorination of tosyl cellulose, Macromol. Symp., 197 (2003) 243—254. 

Preconcentration of trace elements Tosyl cellulose treated with piperazine and CS2 (cellulose piperazinedithiocarboxylate)... 

The Sn reaction of tosyl cellulose with NaN3 was comprehensively studied. It appears that not only the primary but also the secondary tosylates may be substituted. Consequently, the DS of azide moieties exceeds a value of 1, which is not possible with most of the nucleophils studied [53]. The reduction of the azide moiety is possible either with L1A1H4 [54] or NaBH4/CoBr2/2,2 -bipyridine [55]. 

Propargyl amine 80 °C, 24 h in DMSO GeUulose (6-tosyl, cellulose) [54]... 

Scheme 21 Synthesis of PROZO-grafted cellulose initiated from tosylated cellulose.

Multifunctional initiators based on, for example, cyclotriphosphazine [106], silesquioxane [107], porphyrin [108] and bipyridine metal complex [109, 110] cores were also successfully used for the living cationic ring-opening (co)polymerization of 2-oxazolines, resulting in star-shaped (co)polymers. The use of polymeric initiators also allowed the construction of well-defined complex macro molecular architectures, such as triblock copolymers with a non-poly(2-oxazo-line) middle block that is used to initiate the 2-oxazoHne polymerization after functionalization with tosylate end-groups [111-113]. In addition, poly(2-oxazoline) graft copolymers can be prepared by the inihation of the CROP from, for example, poly(chloromethylstyrene) [114, 115] or tosylated cellulose [116]. 

Fig. 3 Suggested mechanisms for the reaction of cellulose with tosyl chloride in the presence of pyridine (Py) and/or triethylamine (EtsN) base catalyst. Redrawn from [147]...

Fig. 7 Use of tosyl chloride as an acid activator for the synthesis of cellulose esters, from [23]...

As shown, an asymmetric carboxylic-sulfonic acid anhydride is formed, but the cellulose attack occurs on the C = O group, since a nucleophilic attack on sulfur is slow, and the tosylate moiety is a much better leaving group than the carboxylate group [193]. Similar to other acylation reactions, there is a large preference for tosylation at the 5 position, and cellulose tosylates... 

Two of the hydroxyl groups present in each glucose unit of the cellulose are secondary, one is primary. Studies on the relative rates of etherification of the three hydroxyls are not conclusive. Mahoney and Purves,18 using a method which takes advantage of the rapid reaction between tosyl chloride and a primary hydroxyl, combined with a determination of unsubstituted glycol groups, have studied the relative num-... 

The double dehydrochlorination of 2,6-dichloro-l-oxacyclohexanes to 4//-pyran (5) and its 4-methyl homolog7,9,19,57 has been mentioned in Section III,A. Another double dehydration occurs in the synthesis of 4,4-diphenyl-4//-pyran 280 in 80% yield by the action of tosyl chloride on 2,6-dihydroxytetrahydropyran 279 in pyridine.296 Another diphenyl derivative (mp 56°C) was reported to be isolable from a mixture after the reaction of cellulose with benzene in sulfuric acid.297... 

Acetone-soluble cellulose acetate is prepared by deacetylating cellulose triacetate. The product formed directly is unsatisfactory. Thus the distribution of free hydroxyls and acetate groupings is of primary importance. Cramer and Purves118(b) studied the distribution by tosylation and found that the acetyl removal from primary and secondary hydroxyl groups occurs at approximately the same rate, but that the number of... 

Sometimes, the sulfonyl chloride is dissolved in an indifferent, water-immiscible solvent. Thus, tosylation of cellulose was brought about by treating alkali-cellulose with a solution of p-toluenesulfonyl chloride in carbon tetrachloride,6061 benzene,61-64 or toluene.56 The number of... 

Sometimes, an extraneous, dry, inert or non-polar solvent1 16 70 is added. Thus, methyl tetra-0-/3-naphthylsulfonyl-a-D-glucopyranoside was synthesized14 in quinoline-chloroform at 40°, and cellulose was sulfonylated 71 by means of a sulfonyl halide plus pyridine, quinoline, triethylamine, or diethylaniline, in the presence of nitrobenzene or other indifferent solvent. Raymond and Schroeder72 successfully employed acetone as added solvent in tosylation of l,2 3,4-di-0-isopropylidene-D-... 

Again, Hess and Ljubitsch106 remarked that a combination of the phenomena of sulfonylation, chlorination, and quaternization failed to provide a coherent explanation for their observations on the prolonged treatment of cellulose with tosyl chloride in pyridine. Re-examination thereof, with special attention to the possible formation of anhydro rings (and, perhaps, of double bonds), is indicated. 

Soon after the application of sulfonylation to sugar derivatives, the action of hydrazine17 on l,2 5,6-di-0-isopropylidene-3-0-tosyl-D-glucose, and of ammonia297 on l,2 3,4-di-0-isopropylidene-6-0-tosyl-D-galactose, was found to proceed similarly. Immediate application of this principle to preparation298 of aminated cellulose derivatives,86299 of possible... 

Methyl 2,3-isopropylidene-a-L-rhamnopyranoside was converted into the 4-tosyl derivative (LVII), from which the isopropylidene residue was removed by mild hydrolysis. Methylation then gave methyl 2,3-di-methyl-4-tosyl-a-L-rhamnopyranoside (LVIII), from which the reductive fission of the aromatic residue with sodium amalgam followed by hydrolysis gave 2,3-dimethyl-L-rhamnose (LIX).68 The same product was obtained by the substitution of benzoyl for tosyl, followed by methylation and separation on a column of cellulose.84 In an earlier synthesis,89 2,3-isopropylidene-L-rhamnose was converted into the 1,5-dibenzyl ether (LX) by treatment with benzyl chloride and potassium hydroxide. 

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