Toluenesulphonyl azide

Sulphoximines may also be obtained from sulphoxides by reaction with benzene- and toluenesulphonyl azides . Yields are often nearly quantitative and the reaction is usually carried out in the presence of copper. This reaction shows a high degree of stereospecificity for example, if (R)-methyl p-tolyl sulphoxide is the reactant then (S)-methyl-S-p-tolyl-iV-p-toluenesulphonylsulphoximine is the product (equation 66). It has been suggested that this reaction involves the intermediacy of a nitrene species . ... 

Interestingly, no SO 2 was evolved in this reaction as in the photolysis of a-toluenesulphonyl azide. This could be explained on the basis of a cation-radical anion pair which collapses as in Eq, (8) to give a sulphon-amido radical, and no free nitrene is formed 21>. 

Homer and Bauer 23> initiated the thermal free radical decomposition of -toluenesulphonyl azide in isopropanol with diethyl peroxydicar-bonate and formulated the mechanism as follows ... 

Arylsulphonyl nitrenes usually give better yields of hydrogen-abstraction products from aliphatic hydrocarbons. -Toluenesulphonyl azide gave a 5% yield of -toluenesulphonamide on thermolysis in cyclohexane... 

In contrast with these ring expansion processes, photoelimination of nitrogen from ethyl o-azidobenzimidate (114) is followed by cyclization with the formation of 3-ethoxy-IH-indazole (115), and irradiation of the 2-azidopyrazines (116) yields the ring-contracted 1-cyanoimidazoles (117), presumably via the nitrenes (118). Products derived by insertion of (p-toluenesulphonyl)nitrene are obtained on irradiation of p-toluenesulphonyl azide in p-xylene or cyclohexane. "... 

The diazo transfer reaction, which involves the transposition of two nitrogen atoms from -toluenesulphonyl azide to a carbanion, wais first utilized by Doering and De Puy in the synthesis of diazocyclo-pentadiene (equation 138). The diazo transfer reaction has since... 

Although the mechanism of this reaction has yet to be fully established certain of its aspects have been defined. The intermediacy of the anion 269 is very probable, particularly since a solid which is presumably the intermediate (269 R = CgHs) has been isolated from the reaction of anilide ion with p-toluenesulphonyl azide. In support of the structural assignment this solid gave a mixture of phenyl azide (40%) and aniline when heated. The reaction sequence has been summarized as shown in equation (139). 

Table 7. Decomposition of/>-toluenesulphonyl azide in various solvents ...

Decomposition of methanesulphonyl azide in a mixture of benzene and substituted benzene resulted in the following total rate ratios for sulphonamidation anisole, 2 54 toluene, 1-86 and chlorobenzene, 0-44 i52 For benzenesulphonyl azide the values were 0-96, 1-00 and 0-69 respectively . In a similar experiment, ring substitution in p-xylene by / -toluenesulphonylnitrene was shown to take place 2-2 times as rapidly as in benzene When //-toluenesulphonyl azide was decomposed in an equimolar mixture of benzene and cyclohexane at 165°, it was found that the benzene double bond is about eight times more reactive than a G—H bond in cyclohexane . ... 

Enamines react readily with sulphonyl azides to give various products, depending on the structure of the enamine. For example, with enamine (285) and /(-toluenesulphonyl azide, the sulphonamidine... 

Vinyl ethers also react readily with sulphonyl azides to give imino-esters. For example, from dihydropyran and j -toluenesulphonyl azide, the arylsulphonylimine of S-valerolactone (290) was obtained in quantitative yield... 

The reaction of benzene- and toluenesulphonyl azides with tetra-methyllallene has been studied recently . A 26% yield of iV-(l,2,3-trimethyl-2-butylidene)benzenesulphonamide (291) was obtained with benzenesulphonyl azide. 

When j6-toluenesulphonyl azide was heated at 50-80° in isopropyl alcohol in the presence of diethyl peroxydicarbonate (20-3 azide 1 -4 peroxide), -toluenesulphonamide and acetone were obtained in 75 and 81% yields respectively " . It was thought that the 2-hydroxy-t-propyl radical (292) added to the azide to give 293 (equation 132) and that an intramolecular reduction and elimination of nitrogen occurred via a cyclic intermediate (294) to give the radical (295) and acetone. Hydrogen abstraction by (295) would then give the sulphonamide. 

Reactions of this type were first studied by Curtius and co-workers . For example, diethyl malonate and /(-toluenesulphonyl azide reacted in the presence of cold sodium ethoxide to give the sodium salt of the 5-hydroxytrizizole (296) . Acidification gave the 5-triazolone (297) which isomerized to the diazo compound (298) (overall yield 90%). (The same product could be obtained in 85% yield without base by heating the azide and malonate at 100° and a pressure of 20 mm) . This reaction provided the basis for the so-called diazo-transfer reaction, an extremely useful method of synthesizing diazo compounds, which has been reviewed. The reaction has been formulated as shown in equation (134), and has been extended to the synthesis of azides by a diazo transfer to amine anions/i-Toluenesulphonyl azide reacts with hydrazone... 

Photolysis of sulphonyl azides in the presence of nucleophilic trapping agents such as dimethyl sulphoxide or dimethyl sulphide gave imine derivatives. For example, irradiation of -toluenesulphonyl azide in dimethyl sulphide gave a 54% yield of iV-( -toluenesulphonyl) dimethylsulphimine (375) The use of dimethyl sulphoxide resulted in lower yields of the trapped nitrene (377) (13-32%), and... 

Photolysis of j -toluenesulphonyl azide in methanol gave, as the main product, A -(/)-toIuenesulphoiiyl)-0 -methylhydroxylamine (378) (44%) Irradiation of benzenesulphonyl azide in methanol gave... 

Cycloaddition of benzonitrile oxide (28) to myrcene (27) occurs with reaction at both the conjugated double bonds, yielding the two adducts (29) and (30). The less reactive 1,3-dipoles, diazomethane, diphenylnitrilimine, and phenyl- and p-toluenesulphonyl-azide, were unreactive. ... 

In this procedure, the C-phosphorylated active methylene compound is first converted into its anion, through its reaction with KOBu BuLi, PhLi, NaH or even Et3N, and the anion is then acted upon by a sulphonyl azide the latter has been / -toluenesulphonyl azide in most recorded examples of the reaction. The first example of the adoption of this procedure to the synthesis of a phosphonic acid derivative appears to have been the conversion of triethyl phosphonoacetate into the diazo derivative (2). Since then, the procedure has been used to obtain A-substituted derivatives of the phosphonoacetamide corresponding to structure 2, but the primary amide itself undergoes further reaction to afford the C-phosphorylated 1,2,3-triazole (3)". Tetraethyl methylenebisphosphonate yields tetraethyl... 

Naphthalenylsulphonyl azide has been advocated as a diazo transfer reagent of a capability superior to that of/ -toluenesulphonyl azide s. 

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