Acyl tosylates

Acylamino-diorgano- (Salze) Ell, 389 (S-Acylaminier.) (Acyl-tosyl-amino)-dialkyl-... 

H-Azepine, 2-methyl-1-methoxycarbonyl-rearrangement, 7, 504 1 //-Azepine, 3-methyl-1 -methoxycarbonyl-cycloaddition reactions, 7, 520 IH-Azepine, 1-phenyl-synthesis, 7, 542 1 H-Azepine, N-phthalimido-formation, 7, 508 IH-Azepine, N-sulfonyl-UV spectra, 7, 501 1 H-Azepine, tetrahydromethylene-synthesis, 7, 540 IH-Azepine, N-p-tosyl-protonation, 7, 509 synthesis, 7, 537 3H-Azepine, 3-acyl-2-alkoxy-synthesis, 7, 542-543 3H-Azepine, 3-acyl-2-methoxy-rearrangements, 7, 505 3H-Azepine, 2-alkoxy-hydrolysis, 7, 510... 

Electrolysis, Me4N Cl , 5°, 65-98% yield. " Acylation of a tosylated amine with BOC or benzoyl reduces the potential required for electrolytic cleavage so that these aryltosyl groups can be selectively removed in the presence of a simple tosylamide. °... 

The Hurd-Mori 1,2,3-thiadiazole synthesis is the reaction of thionyl chloride with the N-acylated or tosylated hydrazone derivatives 1 to provide the 1,2,3-thiadiazole 4 in one simple step. ... 

In general, the reaction can be performed between 0-60°C with the majority of the reactions being run at room temperature. The reactivity of the hydrazones with either the acyl or tosyl leaving group with thionyl chloride depends on the substrate. However, the acylated hydrazones generally provide gaseous by-products where as the tosyl chloride reaction products have to be separated from the reaction mixture. 

With Af-acyl or Af-sulfonyl hydrazines as nucleophiles, Zincke salts serve as sources of iminopyridinium ylides and ylide precursors.Reaction of the nicotinamide-derived Zincke salt 8 with ethyl hydrazino urethane 42 provided salt 43, while the tosyl hydrazine gave ylide 44 (Scheme 8.4.14). ° Benzoyl hydrazines have also been used in reactions with Zincke salts under similar conditions.Af-amino-1,2,3,6-tetrahydropyridine derivatives such as 47 (Scheme 8.4.15), which showed antiinflammatory activity, are also accessible via this route, with borohydride reduction of the initially formed ylide 46. ... 

It was recently shown that the formation of a Schiff s base is the first step of the reaction between 3-aminopropan-l-ol and an aldehyde. The action of acid chlorides, such as tosyl chloride, on the SchifTs base forms the W-acyl derivative of tetrahydro-1,3-oxazine. 

TosyI-l-acyl-hydrazine werden durch Lithiumalanat in einer den p-Tosyl-hydrazo-nen ahnlichen (s. S. 368ff.) Reaktion zu Kohlenwasserstoffen reduziert2 ... 

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... 

Recent progress of basic and application studies in chitin chemistry was reviewed by Kurita (2001) with emphasis on the controlled modification reactions for the preparation of chitin derivatives. The reactions discussed include hydrolysis of main chain, deacetylation, acylation, M-phthaloylation, tosylation, alkylation, Schiff base formation, reductive alkylation, 0-carboxymethylation, N-carboxyalkylation, silylation, and graft copolymerization. For conducting modification reactions in a facile and controlled manner, some soluble chitin derivatives are convenient. Among soluble precursors, N-phthaloyl chitosan is particularly useful and made possible a series of regioselective and quantitative substitutions that was otherwise difficult. One of the important achievements based on this organosoluble precursor is the synthesis of nonnatural branched polysaccharides that have sugar branches at a specific site of the linear chitin or chitosan backbone [89]. 

Sulfonic esters are most frequently prepared by treatment of the corresponding halides with alcohols in the presence of a base. The method is much used for the conversion of alcohols to tosylates, brosylates, and similar sulfonic esters. Both R and R may be alkyl or aryl. The base is often pyridine, which functions as a nucleophilic catalyst, as in the similar alcoholysis of carboxylic acyl halides (10-21). Primary alcohols react the most rapidly, and it is often possible to sulfonate selectively a primary OH group in a molecule that also contains secondary or tertiary OH groups. The reaction with sulfonamides has been much less frequently used and is limited to N,N-disubstituted sulfonamides that is, R" may not be hydrogen. However, within these limits it is a useful reaction. The nucleophile in this case is actually R 0 . However, R" may be hydrogen (as well as alkyl) if the nucleophile is a phenol, so that the product is RS020Ar. Acidic catalysts are used in this case. Sulfonic acids have been converted directly to sulfonates by treatment with triethyl or trimethyl orthoformate HC(OR)3, without catalyst or solvent and with a trialkyl phosphite P(OR)3. ... 

Acylation reactions of 2,5-bis(o-amino-phenyl)-1,3,4-oxadiazoles with an excess of chiral /V-tosyl-/-lcucyl chloride were performed in dry pyridine <2000JST109>. 

---