Sulfonyl azides azidation

Further studies revealed that the yields of l//-azepines could be increased substantially by carrying out the thermolysis of the sulfonyl azide in a nitrogen atmosphere under pressure.62-158159 For example, thermolysis of tosyl azide in benzene at 155-160 C and a nitrogen pressure of 11.5 atmospheres produced l-tosyl-l//-azepine in 5% yield, which rose to 48% under a nitrogen pressure of 82-89 atmospheres.158 The reaction temperature was critical as no azepine was formed at 140-145°C-regardless of the nitrogen pressure.160... 

Far superior yields of l-(arylsulfonyl)-l//-azepines 16 are now available by a one-pot synthesis involving the action of sodium azide on an arylsulfonyl chloride under solid-liquid phase-transfer conditions which prevents the formation of acidic sulfonamides and, hence, the ring-contraction process.75 This procedure also has the advantage of avoiding the use of high pressures and the isolation and handling of the potentially explosive sulfonyl azides. 

Mg or Ca in MeOH, " baker s yeast, Sm/l2, LiMe2NBH3, and tin complexes prepared from SnCl2 or Sn(SR)2. This reaction, combined with RX —+ RN3 (10-65), is an important way of converting alkyl halides RX to primary amines RNH2 in some cases the two procedures have been combined into one laboratory step. Sulfonyl azides (RSO2N3) have been reduced to sulfonamides (RSO2NH2) by irradiation in isopropyl alcohol and with NaH. ... 

Besides short ELPS, longer ELPs have also been conjugated to synthetic polymers. In one approach, Cu(I)-catalyzed azide-alkyne cycloaddition click chemistry was applied. For this purpose, ELPs were functionalized with azides or alkynes via incorporation of azidohomoalanine and homopropargyl glycine, respectively, using residue-specific replacement of methionine in ELP via bacterial expression [133]. More recently, an alternative way to site-selectively introduce azides into ELPs was developed. Here, an aqueous diazotransfer reaction was performed directly onto ELP[V5L2G3-90] using imidazole-1-sulfonyl azide [134]. 

Sulfonylnitrenes are formed by thermal decomposition of sulfonyl azides. Insertion reactions occur with saturated hydrocarbons.255 With aromatic compounds the main products are formally insertion products, but they are believed to be formed through addition intermediates. 

The impure compound, present as a majority in the distillation residue from preparation of 1-diazoindene, will explode if the bath temperature exceeds 120°C [1], A polymer-bound sulfonyl azide reagent has been described as safer in use than the title compound [2], Distillation of the azide at 130-132 C/ 0.5 mbar from an oil bath at 145°C led to darkening, then violent explosion of the 30-40% residue [3],... 

The direct, stereoselective conversion of alkynes to A-sulfonylazetidin-2-imines 16 by the initial reaction of copper(l) acetylides with sulfonyl azides, followed, in situ, by the formal [2+2] cycloaddition of a postulated A-sulfonylketenimine intermediate with a range of imines has been described <06AG(E)3157>. The synthesis of A-alkylated 2-substituted azetidin-3-ones 17 based on a tandem nucleophilic substitution followed by intramolecular Michael reaction of primary amines with alkyl 5-bromo-4-oxopent-2-enoates has been... 

Decomposition of sulfonyl azides was shown to be catalyzed by copper in 1967 (72, 73). In the presence of alkenes, the reaction provides both aziridines and the C-H insertion products, albeit in low yields (73). In 1991, Evans et al. (74, 75) illustrated that both Cu(I) and Cu(II) salts were effective catalysts for nitrenoid transfer from [A-(/Moluenesulfonyl)imino]phenyliodinane (PhI=NTs) to a variety of acceptor alkenes. In the absence of ancillary ligands, reactions proceed best in polar aprotic solvents such as acetonitrile. Similar results are observed using both Cu(MeCN)4C104 and Cu(acac)2 as precatalysts, Eq. 53. 

A reaction known as diazo group transfer produces diazo barbituric acid from barbituric acid and p-toluene sulfonyl azide. Additional barbituric acid affords azo barbituric acid [7]. Subsequent complexation with a nickel (II) salt yields a greenish yellow pigment. 

Acetyl azide, 0771 A-Azidocarbonylazepinc, 2728 Azidocarbonyl fluoride, 0339 Azidocarbonylguanidine, 0820 4-Azidocarbonyl-1,2,3-thiadiazole, 1069 Azidodithioformic acid, 0386 Benzene-l,3-bis(sulfonyl azide), 2210 Benzenesulfinyl azide, 2273 Benzenesulfonyl azide, 2274 Benzoyl azide, 2698... 

Methylaminobenzene-l,3-bis(sulfonyl azide), 2785 4-Nitrobenzenesulfinyl azide, 2204 Palladium(II) azidodithioformate, 1015... 

Bis-acceptor-substituted diazomethanes are most conveniently prepared by diazo group transfer to CH acidic compounds either with sulfonyl azides under basic conditions [949,950] or with l-alkyl-2-azidopyridinium salts [951] under neutral or acidic conditions [952-954]. Diazo group transfer with both types of reagents usually proceeds in high yield with malonic acid derivatives, 3-keto esters and amides, 1,3-diketones, or p, y-unsaturated carbonyl compounds [955,956]. Cyano-, sulfonyl, or nitrodiazomethanes, which can be unstable or sensitive to bases, can often only be prepared with 2-azidopyridinium salts, which accomplish diazo group transfer under neutral or slightly acidic reaction conditions. Other problematic substrates include amides of the type Z-CHj-CONHR and P-imino esters or the tautomeric 3-amino-2-propenoic esters, which upon diazo group transfer cyclize to 1,2,3-triazoles [957-959]. 

When 2-alkyl-3-keto esters or 2-aryl-3-keto esters are treated with sulfonyl azides under basic conditions, nucleophilic deacylation occurs to yield 2-alkyl/aryl-2-diazo esters [960-963]. Nucleophilic deacylation can also be used to convert acceptor-substituted diazoketones into the corresponding acceptor-substituted diazomethanes [964,965]. In all these deacylation reactions it is the most electrophilic carbonyl group which is attacked by the nucleophile and cleaved off. 

Synthesis of 2-diazo-l,3-dicarbonyl or 2-diazo-3-ketoesters using sulfonyl azide. 

Toluene-p-sulfonyl azide adds to electron-deficient acetylenes and to phenylacetylene at 80°-100° over a period of several days. The azide adds much more readily to ynamines, - refiecting the electronic compatibility of these components. The triazoles so formed are labile and exist in equilibrium with open-chain diazo tautomers (Section IV, G) the adduct with ethoxyacetylene exists entirely in the diazo form. Other sulfonyl azides have been reacted with arylacetylenes, but yields of triazoles are generally poor. ... 

Sulfonyl azides are exceptional in that they do not normally give triazoles with activated methylene compounds nucleophilic attack by the carbanion is usually followed by loss of the sulfonamide anion, giving a diazo compound as the product. Possible mechanisms for the reaction are illustrated (Scheme 8) for diethyl malonate. Attack of the carbanion on the terminus of the azide gives the anion of the linear triazene (1). 

Closure to the triazoline certainly occurs in many systems, since products are isolated which can only have been formed by this route. Occasionally these products include w-triazoles for example, 4-phenyl-triazole is isolated in moderate yield from the reaction of the aldehydes (3) with toluene-p-sulfonyl azide (Scheme 9). ... 

Triazoles have also been obtained when the carbon atom adjacent to the activated methylene group carries a nitrogen function (i.e., amides, nitriles, amidines, and imines - ). In many of these cases it is impossible to decide, without N-labeling experiments, whether the third nitrogen of the triazole ring is derived from the toluene-p-sulfonyl azide or from the activated methylene compound. With amides, amidines, and nitriles, the first possibility seems more reasonable, but with imines, the third nitrogen is that of the imino group (Scheme... 

The reaction is most effective with azides bearing electron-withdrawing groups, such as nitrophenyl, toluene-p-sulfonyl, and ethoxy carbonyl. Sulfonyl azide adducts give iV-unsubstituted triazoles, the substituent being lost on aromatization. The triazole which is isolated as a minor product of the reaction of 1,1-dimethoxyethylene with ethoxycarbonyl azide has been assigned a 2/7-triazole structure it is likely that other ethoxycarbonyltriazoles formed by this route also have 2H-structures. 

A 1-toluene-p-sulfonyl substituent is reported to be removed by boiling the triazole in ethanol. Many triazole syntheses involving cycloaddition of toluene-p-sulfonyl azide give the NH triazole directly. 

The HC1 generated in this reaction destroys one equivalent of diazomethane. This can be avoided by including a base, such as triethylamine, to neutralize the acid.74 Cyclic z-diazoketones, which are not available from acyl chlorides, can be prepared by reaction of an enolate equivalent with a sulfonyl azide. This reaction is called diazo transfer 5 Various arenesulfonyl azides76 and methanesulfonyl azide77 are used most frequently. Several types of compounds can act as the carbon nucleophile. These include the anion of the hydroxymethylene derivative of the ketone78 or the dialkylaminomethylene derivative of... 

In addition to previously described syntheses4-5 by diazo group transfer with deformylation,6 2-diazocyclohexanone has been prepared by two variants of this method. In one, the reaction of 2-(hydroxymethylene)cyclohexanone with -toluene-sulfonyl azide is carried out in ether/diethylamine, and an enamine is assumed to be formed as an intermediate 7 in the other, the sodium salt of the hydroxymethylene compound was treated with the lithium salt of p-carboxybenzenesulfonyl azide... 

A mixture of sulfonyl-azafulleroid 168 and sulfonylaziridino-fullerene 169 was obtained by reaction of sulfonyl azide with CgQ in o-dichlorobenzene at 160 °C (Scheme 4.30) [173]. The ratio of the two products depends on the substituent of the sulfonyl group. In all cases the aziridino fullerene can be obtained from the azafulleroids by irradiation. 

However, product smdies indicate that the chemistry of sulfonyl azides and nitrenes is complicated by rearrangement to form intermediates, such as 21. ... 

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