Substituted Azides

The thermolysis of aryl azides in alcoholic solution has been used to prepare 2-alkoxy-37f-azepines. Thermolysis of 3-azidophenyl methyl ketone in methanol in a sealed ampule furnishes a mixture of the 6-acetyl- (36a) and 4-acetyl-2-methoxy-3//-azepine (37a) in superior yields to those obtained in the corresponding photolytic reaction.78 Other 3-substituted azides behave similarly, with a preference for the 6-substituted isomers 36, as is observed for azide photolyses in amine solutions. 

Practicable yields of 5-substituted 2-methoxy-3//-azepines 94 can be obtained by photolysis of aryl azides 56 bearing an electron-withdrawing group para to the azide function, although irradiation times tend to be longer and, in general, yields lower than with the corresponding 2-substituted azides.197... 

For ring closure of an o-substituted azide on to a double bond see Section 3.3.3.4.3. 

Syntheses based not only on compounds 426 but also on other 1,8-disubstituted naphthalenes have been described. Thus, decomposition of peri-diazonium-substituted azides 432 in carbon disulfide, proceeding by the free radical mechanism, yields naphtho[de]-l,3-thiazine-2-thiones 433... 

Earlier we have studied the reactions of fullerene Cgo with the isocyanurato-, phosphoryl-, pyrimidino-, nitropyrimidino-, quinoxalin-, benzopyrazine substituted azides [18-24]. As a result, both 6,6-, 5,6-closed and 5,6-open organofullerens were synthesized, and the series of them were reduced electrochemically easier than the pristine fullerene C6o- Now the reactions of fullerene C6o with isocyanurato- and nitropyrimidine substituted azides were used for the search of the answer to delivered question. For solving the problem the substituents in positions 1 and 3 of the isocyanurate ring and the number of methylene units between ring and azide group in isocyanurate containing azides were varied. 

Romanova I.P., Yusupova G.G., Nafikova A.A., Kovalenko V.I., Sinyashin O.G. (2002) Synthesis of a single isomer of the bis-adduct of isocyanurato-substituted azide with [60]fullerene, Russian Chemical Bulletin, Int. Ed. 51, 1491-1496. 

The difficulty in trying to forecast which way round a 1,3-dipolar cycloaddition will go is well illustrated when a substituted azide adds to an alkyne in the synthesis of 1,2,3-triazolcs. Reaction of an alkyl azide with an unsymmetrical alkyne, having an electron-withdrawing group at one end and an alkyl group at the other, gives mostly a single triazole. 

The heterocyclic hemi-aminal 44 was formed as a model for the synthesis of the marine alkaloids zoanthamine and zoanthenol and is derived from the cyclic imine formed by the reduction of an appropriated substituted azide <07H(72)213>. A pyrrolidine-fused azepine has been isolated from the venom of the ant Myrmicaria melanogaster and assigned as 45 based upon GC and FT-IR comparison with synthetic material <07JNP160>. The axially chiral doubly bridged biphenyl azepine 46 has been synthesised and used with oxone as an epoxidation catalyst in a biphasic system <070BC501>. 

A single di(azahomo)[60]fullerene 25 (see Section 14.06.3.1) was prepared by the reaction between [60]fullerene and isocyanurato-substituted azide 90 (Equation 17) <2002RCB1491>. 

The examples of aziridination with strongly electronegatively substituted azides cited earlier (Section... 

The reaction of an exocyclic methylene group with 7V-phenylselcnophthalimide (A -PSP) and azidotrimethylsilane affords cyclic / -phenylseleno-substituted azides (Table 10)97. 

Straight chain triazenes may be considered as substituted azides and so will be mentioned here very briefly. The best known rearrangements involving such compounds are the acid-promoted conversions of diazoaminoarenes into />-aminoazoarenes, which are universally considered to be intermolecular (reaction 82). This reaction has been recently reviewed and only two points need adding. Firstly, that the intermolecular route is supported by N-tracer studies that reveal, for instance, that step (a) comes to equili-... 

This synthetic project makes provision for the regioselective oxidation of allylic hydroxyl of 13h with Jones s reactant in acetone this reaction provided the keto derivative 13i quantitatively only when we operates with small substrate quantities (few milligrams). Then the hydroxyl at C-4 has been esterified with methanesulfonyl chloride the mesylation reaction has been led in methylene chloride in presence of triethylamine at 0°C and it has brought to the formation of product 131. Then it has been substituted azide for mesyl group by the treatment of mesyl derivative 131 with sodium azide in dimethylformamide at SOX, so obtaining product 13m. 

Reaction of the a-heteroatom-substituted azides 31 and 32 with 2-phenethyl-magnesium bromide proceeds with equal rates at —78° analog 33 only reacts at 0°, whereas both azides 34 and 35 are essentially unreactive at this temperature.273 Both aliphatic (see Eq. 40) and aromatic Grignard reagents, but not aromatic lithium reagents, may be used with azide 32, which has a low steric requirement as evidenced by its reaction with the exo and endo isomers of 2-norbomylmagnesium bromide at about equal rates274 (see also Eq. 39). 

On the basis of product studies, it is clear that irradiation of the naphthyl azides leads to loss of nitrogen with the likely consequent formation of nitrenes. Just as for phenyl azide, the initially formed singlet nitrenes may intersystem cross to the triplet and then dimerize to azo compounds. Clearly in the case of 2-naphthyl azide, but not 1-naphthyl azide, a closed-shell ground-state intermediate that can be trapped with diethylamine can be generated. The intermediate was formulated as the azirine on the basis of product studies [57]. Low temperature absorption spectroscopy and time-resolved laser flash photolysis experiments to be described later support the formation of azirines and provide an explanation for the different reactivity observed between the 1- and 2-substituted azides. 

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