Iodine derivatives, azidation

Sodium azide/iodine monocliloride Azidoiodides from ethylene derivatives Stereospecific fra/i5-addition... 

Onuska, F.I. Comba, M.E. Sodium azide-iodine reagent for the detection of 1,4-oxathiin derivatives by thin-layer chromatography. J. Chromatogr. 1974, 100, 247-248. 

Addition of iodine azide to the D-glucal derivatives (39) gave mostly 2-deoxy-2-iodo-glycosyl azides (40) derived from trans-diaxial addition to the double bond. D-galactal and D-xylal derivatives... 

Insulin derivatives lb 401 lodate anions la 188,190 lb 307 Iodine staining lb 278 Iodine-azide reaction lb 85,301-304 Iodide anions la 190 lb 76,77,128,129 Iodide vapor la 46,64,78 lodination la 66... 

In reactions with azides, ketones are directly converted to 5-hydroxytriazolines. Ketone enolate 247, generated by treatment of norbornanone 246 with LDA at 0°C, adds readily to azides to provide hydroxytriazolines 248 in 67-93% yield. Interestingly, l-azido-3-iodopropane subjected to the reaction with enolate 247 gives tetracyclic triazoline derivative 251 in 94% yield. The reaction starts from an electrophilic attack of the azide on the ketone a-carbon atom. The following nucleophilic attack on the carbonyl group in intermediate 249 results in triazoline 250. The process is completed by nucleophilic substitution of the iodine atom to form the tetrahydrooxazine ring of product 251 (Scheme 35) <2004JOC1720>. 

A comprehensive review covers stability relationships and reactions of these explosive compounds and their derivatives. Bromine, chlorine and iodine azides all explode violently in contact with magnesium, zinc or white phosphorus. 

In the case of electrophilic addition, the reactions of tricyclic dienes 1 with several electrophilic reagents have been investigated.1 7 Interestingly, some of these compounds undergo addition reactions with remarkable syn stereoselectivity. For example, the reaction of dimethyl tricy-clo[4.2.2.02,5]deca-3,9-diene-7,8-dicarboxylate with iodine azide solution, prepared in situ from an excess of sodium azide and iodine monochloride, in acetonitrile at — 5 C provided the. yyn-4-azido-3-iodo derivative 2 (Table 1) in 90% yield.1,2,4,6 The formation of the 5,>,n-4-azido-3-iodo derivative 2 is thought to be the first example of a syn addition of iodine azide to an alkene.1,2 The formation of the syn-product is best explained by the twist strain theory,8 according to which the syn transition structure A is favored over the an/7-coplanar transition structure B.1... 

Alternatively, the addition of iodine azide under similar conditions to 9,10-dimethyltricy-clo[4.2.2.02,5]deca-3,7-diene produced the tetracyclic tetrazole 3, whose formation possibly involves initial reaction of the solvent acetonitrile with the azide ion.1 The addition proceeds via electrophilic attack of iodine azide with the formation of a three-membered iodonium ion intermediate backside opening of the intermediate results in the anti configuration of the tetrazole derivative (see Table 1). 

Normally, iodanes with one or two azido groups attached to iodine(III) are very labile. Two cyclic iodanes, however, l-azido-l,2-benziodazol-3(lH)-one and its 2-acetoxy derivative, are stable. They are prepared from the corresponding 1-acetoxybenziodazoles by reaction with trimethylsilyl azide (Scheme 25) [76,77]. 

Recent progress on the use of hypervalent iodine reagents for the construction of carbon-het-eroatom (N, O, P, S, Se, Te, X) bonds is reviewed. Reactions of aryl-A3-iodanes with organic substrates are considered first and are loosely organized by functional group, separate sections being devoted to carbon-azide and carbon-fluorine bond formation. Arylations and alkenyla-tions of nucleophilic species with diaryliodonium and alkenyl(aryl)iodonium salts, and a variety of transformations of alkynyl(aryl)iodonium salts with heteroatom nucleophiles are then detailed. Finally, the use of sulfonyliminoiodanes as aziridination and amidation reagents, and reactions of iodonium enolates formally derived from monoketones are summarized. 

One of the best known reactions of 1-azirines is the acid/catalyzed hydrolysis to aminoketones. Since the Neber reaction also accomplishes this same synthetic end, this reaction may appear to have little practical value. This is not the situation because with the Neber reaction there is no control over the aminoketone that will be obtained from a given ketone. For example, when oxime (127) derived from benzyl methyl ketone (126) is subjected to the Neber reaction aminoketone 128 is obtained.59 The amino function is substituted for the most acidic a-hydrogen. The isomeric aminoketone (132) that could not be prepared by the Neber reaction can be formed by the hydrolysis of 1-azirine (131). The synthesis of this 1-azirine has been accomplished from allyl benzene (129) through vinyl azide (130) using iodine azide.22... 

The present volume, Supplement D2 retains the title of its direct predecessor, Supplement D The chemistry of halides, pseudo-halides and azides, even though it deals only with derivatives of fluorine, chlorine, bromine, iodine and astatine. Hence, in order to keep the Chemistry of the functional groups series complete and up-to-date, it will be necessary to publish, in the not too distant future, an additional supplementary volume ( D3 ) discussing the recent advances in the chemistry of azides, cyanates, isocyanates and their thio derivatives. 

Iodine azide, generally made in situ from ICl and NaNa in MeCN at 0 C, adds readily to alkenes by a similar heterolytic mechanism to INCO. Whereas the trans stereochemistry is generally well established,the regiochemistry of the adduct with 1-phenylcyclohexene has been queried recently it was originally formulated as the l-azido-2-iodo compound (Scheme 86), but base treatment was subsequently shown to yield what appeared to be 6-azido-l-phenylcyclohexene, which would have arisen from the l-iodo-2-azido isomer. However, it has very recently teen shown by 3(X) MHz NMR that the elimination product is in fact 3-azido-l-phenylcyclohexene, derived ultimately (Scheme 86) from the originally proposed l-azido-2-iodo- structure. 

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