Toluenesulfonly azide

Titanium(IV) isopropoxide, 64,404-405 Titanocene dichloride, 130-131,423 oc-Tocopherol, 43 Toluenesulfonly azide, 405 (RM+)-(p-Tolysulfinyl)acetic acid, 405-407 (S>(+>p-Tolyl p-tolylthiomethyl sulfoxide, 408-409... 

Reaction of the 2-alkenylnicotinonitrile 305 with trimethylsilyl azide and dibutyltin oxide under microwave irradiation gives a mixture of the tetrazolylpyridine 306 (52%) and the tricyclic tetrazolonaphthyridine 307 (22%). Compound 306 may be cyclized to 307 by treatment with />-toluenesulfonic acid (Equation 105) <2006T1849> and the reaction 305 —> 306 —> 307 may be made into a one-pot procedure, with an overall yield of 68%. 

Toluenesulfonic acid, 25 185, 75 168 Toluenesulfonyl chloride, 25 186 pora-Toluenesulfonic acid, 25 185 p-Toluenesulfonylhydr azide, 13 593 Toluhydroquinone, 20 105 Toluidine... 

In 1984, a facile synthesis of pyrrolo[3,4-/7]indole (5) as a stable indole-2,3-quinodimethane analogue using an intramolecular azide-alkene cycloaddition-cycloreversion strategy was reported (Scheme 9.2) (3). Treatment of bromo compound 3 with NaNs in aqueous tetrahydrofuran (THF) produced the triazoline 4 via an intramolecular 1,3-dipolar cycloaddition of an intermediate azide. Treatment of the triazoline 4 with p-toluenesulfonic acid (p-TSA) effected 1,3-dipolar cycloreversion of 4 to give pyrroloindole 5 in 82% yield along with diethyl diazomalonate. 

The bromomethylindole (200a) cyclized on treatment with sodium azide to give a tetracyclic triazoline.111 Treatment with a catalytic amount of p-toluenesulfonic acid afforded 2,4-dihydropyrrolo[3,4-bjindole (201), presumably via loss of diethyl diazomalonate by cycloreversion and subsequent tautomerization. 

Toluenesulfonic acid, 2804a 4-Toluenesulfonyl azide, 2777 4-ToluenesulfonyIhydrazide, 2823 O-4-Toluenesulfonylhydroxylamine, 2817... 

The hydroxyl group must be replaced by azide with inversion of configuration. First, however, a leaving group must be introduced, and it must be introduced in such a way that the configuration at the stereogenic center is not altered. The best way to do this is to convert (R)-sec-butyl alcohol to its corresponding p-toluenesulfonate ester. 

Lithium aluminium hydride reduction of 235 followed by mesylation afforded 236. The latter was oxidized with osmium tetroxide and sodium metaperiodate to yield the cyclobutanone 237. Treatment of 237 with acid afforded in 48% yield the ketoacid (238), which was esterified with diazomethane to 239. The latter was converted to the ketal 240 by treatment with ethylene glycol and /7-toluenesulfonic acid. Compound 240 was reduced with lithium aluminium hydride to the alcohol 241. This alcohol had been synthesized previously by Nagata and co-workers (164) by an entirely different route. The azide 242 was prepared in 80% yield by mesylation of 241 and treatment of the product with sodium azide. Lithium aluminium hydride reduction of 242 gave the primary amine, which was converted to the urethane 243 by treatment with ethyl chloroformate. The ketal group of 243 was removed by acidic hydrolysis and the resulting ketone was nitro-sated with N204 and sodium acetate. Decomposition of the nitrosourethane with sodium ethoxide in refluxing ethanol afforded the ketone 244 in 65% yield. The latter had been also synthesized previously by Japanese chemists (165). The ketone 244 was converted to the ketal 246 and the latter to 247... 

The 1,2-diols formed by the asymmetric oxidation can be used as substrates in a wide variety of transformations. Conversion of the hydroxy groups to p-toluenesulfonates then allows nucleophilic displacement by azide at both centers with inversion of configuration (Scheme 9.22).161... 

Methyl 4,6-0-benzylidene-3-deoxy-a-D-ribo-hexopyranoside (56) was benzoylated, debenzylidenated, and partially p-toluenesulfon-ylated to 57 this was converted into 58 by reaction with sodium iodide, followed by catalytic reduction. The methanesulfonate of 58 was converted into 59 by reaction with sodium azide in N,N-dimethylformamide, and 59 was converted into 4-azido-3,4,6-trideoxy-a-D-xylo-hexose (60) by acetolysis followed by alkaline hydrolysis. Reduction of 60 with borohydride in methanol afforded 61, which was converted into 62 by successive condensation with acetone, meth-anesulfonylation, and azide exchange. The 4,5-diazido-3,4,5,6-tetra-deoxy-l,2-0-isopropylidene-L-ara/uno-hexitol (62) was reduced with hydrogen in the presence of Raney nickel, the resultant diamine was treated with phosgene in the presence of sodium carbonate, and the product was hydrolyzed under acidic conditions to give 63. The overall yield of 63 from 56 was 4%. The next three reactions (with sodium periodate, the Wittig reaction, and catalytic reduction) were performed without characterization of the intermediate products, and gave (+)-dethiobiotin methyl ester indistinguishable from an authentic sample thereof prepared from (+)-biotin methyl ester. 

More recently another modification for the preparation of peptide azides was introduced by Alfeeva et al-f l using tetrabutylammonium nitrite as auxiliary reagent. In contrast to the alkyl nitrites which are relatively unstable and therefore have to be purified prior to use by distillation, tetrabutylammonium nitrite is a crystalline and stable compound, which is soluble in anhydrous dipolar aprotic solvents. Moreover, in this procedure the acidity of the reaction mixture is adjusted with anhydrous p-toluenesulfonic acid instead of HCl in anhydrous organic solvents. These conditions are experimentally convenient and more easily controlled than those of the Honzl-Rudinger method. Comparative model reactions performed with ferf-butyl nitrite and tetrabutylammonium nitrite produced nearly identical peptide yields. To date, there are no reports of the condensation of larger fragments and peptide cyclization by this azide procedure. 

Aminopyrazine 1-oxide with aqueous nitrous acid followed by sodium azide gave 2-azidopyrazine 1 -oxide (57), which on heating with dry benzene at 85 gave 2-cyano-l-hydroxyimidazole (58) (1261, 1262). 3-Aminopyrazine 1-oxide p-toluenesulfonate fused with cyanoguanidine at 150-155 gave 3-(amidino-... 

The efficient light-initiated decomposition of azides has been the basis for commercially important photoresist formulations for the semiconductor industry. A common approach is to mix a diazide, such as diazadibenzylidenecyclohexanone (I), with an unsaturated hydrocarbon polymer. Excitation of the difunction-al sensitizer produces highly reactive nitrenes which crosslink the polymer by a variety of paths including insertion into both carbon-carbon double bonds and carbon-hydrogen bonds, and by generation of radicals. The polymer component in the most widely used resists is polyisoprene which has been partially eye Iized by reaction with p-toluenesulfonic acid G). Other polymers used include polycyclopentadiene and the copolymer of cyclopentadiene and a-methyI styrene ( ). 

The reaction of alcohol (41) with TFAA, followed by treatment with sodium azide, gave (42) in 75% overall yield. The p-toluenesulfonate or methanesulfonate of (41) has also been demonstrated to react with sodium azide affording (42) but in lower yield. Deprotection and subsequent reduction with hydrogen sulfide gave amine (43 Scheme 19). ... 

Sulfonates do not necessarily show the same reaction pattern as halides. It has been reported that p-toluenesulfonate (51a) and methanesulfonate (51b) reacted with azide ion and cyanide ion to give (52a) and (52b), while iodide (51c) gave (53a) and (53b) (Scheme 22). ... 

Toluenesulfonic anhydride, 1177 p-Toluenesulfonylanthranilic acid, 1181 p-ToIuene ulfonyl azide, 1178-1179 Toluenesulfonyl chloride, 235, 295, 371, 441, 662, 1088-1089, 1179-1184, 1280 / Toluenesulfonyl chloride-Diniethyl-formamide, 1184-1185... 

Tosic acid, see p-Toluenesulfonic add Af-Tosylamino adds, 1184 Tosylates, 958-959,1054 Tosyl azide, see p-Toluenesulfonyl azide Tosyl chloride, see p-Toluenesulfonyl chloride... 

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