Alkenes azides

Figure 14.8 Use of the copper(l)-mediated alkene-azide 1,3-cycloaddition ("click" chemistry) in both organic solvent and aqueous solvent systems. The aqueous system, with in situ generation of copper(l) from copper(II), is less sensitive to oxygen.

The chemoselectivity of DBBS is demonstrated by reacting dibenzyl sulfoxide in the presence of other functional groups, such as alkene, azide, ketone, azide, and 7V-oxide (eq 25). 

Other nitrene precursors have been employed in the aziridination of alkenes. Azides have been shown to form aziridines when photolyzed or thermolyzed in the presence of alkenes, though... 

In support of this mechanism is the fact that stable cobaltacyclopentadienes 11.23, with an additional PPhs ligand can be prepared (Scheme 11.12). These cobaltacycles undergo further reactions with alkynes, alkenes, azides and diazo compounds to give a variety of cyclic products. Cyclobutadiene complexes 11.26, cyclopentadienone complexes 11.27 and arenes 11.28 can also be formed (Scheme 11.13). ... 

This following article was sent to Strike by Osmium and Feck (are they the same person ). It involves the direct addition of azide to a terminal alkene (you-know-who) by the in situ production of the reactant mercury (II) azide from mercuric acetate and sodium azide (please don t ask) [80]. 

That looks simple and direct don t it If safrole was used as the alkene one would get safrole-azide as product. Just one teensy little reduction away from MDA. Strike also found some azide papers that, with a little work, will get safrole-azide in a totally different way. Strike came across a lot of work where groups were using dinucleophilic addition to get an azide and a halogen added across a double bond. The azide would always go to the beta secondary carbon and the halogen to the primary carbon (just what one would want if safrole was the substrate). 

Perhaps one of the most exciting developments in the chemistry of quinoxalines and phenazines in recent years originates from the American University of Beirut in Lebanon, where Haddadin and Issidorides first made the observation that benzofuroxans undergo reaction with a variety of alkenic substrates to produce quinoxaline di-AT-oxides in a one-pot reaction which has subsequently become known as the Beirut reaction . Many new reactions tend to fall by the wayside by virtue of the fact that they are experimentally complex or require starting materials which are inaccessible however, in this instance the experimental conditions are straightforward and the starting benzofuroxans are conveniently prepared by hypochlorite oxidation of the corresponding o-nitroanilines or by pyrolysis of o-nitrophenyl azides. 

The closely related N- arylazoaziridine system (278) decomposes in refluxing benzene to give aryl azides and alkenes, again stereospecifically (70T3245). However, biaryls, arenes and other products typical of homolytic processes are also formed in a competing reaction, although this pathway can be suppressed by the use of a polar solvent and electron withdrawing aryl substituents. 

Iodine azide, 1N3, adds to alkenes by an electrophilic mechanism similar to that of bromine. If a monosubstituted alkene such as 1-butene is used, only one product results ... 

DNA sequencing and. 1113 Electrospray ionization (ESI) mass spectrometry, 417-418 Electrostatic potential map, 37 acetaldehyde, 688 acetamide, 791,922 acetate ion. 43. 53, 56, 757 acetic acid. 53. 55 acetic acid dimer, 755 acetic anhydride, 791 acetone, 55, 56. 78 acetone anion, 56 acetyl azide, 830 acetyl chloride, 791 acetylene. 262 acetylide anion, 271 acid anhydride, 791 acid chloride, 791 acyl cation, 558 adenine, 1104 alanine, 1017 alanine zwitterion, 1017 alcohol. 75 alkene, 74, 147 alkyl halide, 75 alkyne. 74... 

When unacylated azides are used as nitrene precursors, the first reaction with an alkene is a cydoaddition, generating the corresponding 1,2,3-triazoline, which often eliminates N2 under the fierce reaction conditions to give an aziridine product (Scheme 4.9 ). 

Since the mid-1990s, synthetic attention has been directed more towards the use of metal-stabilized nitrenes as synthetic effectors of alkene aziridination. In 1969 it was reported that Cu(i) salts were capable of mediating alkene aziridination when treated with tosyl azide, but the method was limited in scope and was not adopted as a general method for the synthesis of aziridines [12]. Metaloporphyrins [13] were shown to be catalysts for the aziridination of alkenes in the presence of the nitrene precursor N-tosyliminophenyliodinane [14] in the early 1980s, but the reaction did... 

Another conceptually unique approach in alkene aziridination has come from Johnston s labs. These workers shrewdly identified organic azides as nitrene equivalents when these compounds are in the amide anion/diazonium resonance form. Thus, when a range of azides were treated with triflic acid and methyl vinyl ketone at 0 °C, the corresponding aziridines were obtained, in synthetically useful yields. In the absence of the Bronsted acid catalyst, cycloaddition is observed, producing triazolines. The method may also be adapted, through the use of unsaturated imi-des as substrates, to give anti-aminooxazolidinones (Scheme 4.25) [32]. 

Arenesulphinylation 264 Arenesulphinylethanes, synthesis of 267 2-Arenesulphonyl-3-aryloxaziridines, as oxidizing agents 254 Arenesulphonyl azides, reactions of 641 At-Arenesulphonyliminopyridinium betaines, mass spectra of 160-162 Arenesulphonyl radicals 215, 1091 Aryldiazonium salts, reactions of 280, 281 Aryl(methylsulphinyl)(methylthio)alkenes, synthesis of 614... 

Organoboranes react with a mixture of aqueous NH3 and NaOCl to produce primary amines. It is likely that the actual reagent is chloramine NH2CI. Chloramine itself,hydroxylamine-O-sulfonic acid in diglyme, and trimethyl-silyl azide " also give the reaction. Since the boranes can be prepared by the hydroboration of alkenes (15-16), this is an indirect method for the addition of NH3 to a double bond with anti-Markovnikov orientation. Secondary amines can be prepared by the treatment of alkyl- or aryldichloroboranes or dialkylchlorobor-anes with alkyl or aryl azides. 

Hydrazoic acid can be added to certain Michael-type substrates (Z is as defined on p. 975) to give 3-azido compounds. The reaction apparently fails if R is phenyl. Ammonia also adds to enol ethers CH2=CHOR to give CH3—CH(OR)N3, and to silyl enol ethers, but it does not add to ordinary alkenes unless a Lewis acid catalyst, such as TiCU, is used, in which case good yields of azide can be obtained. Ammonia can also be added indirectly to ordinary alkenes by azidomercuration, followed by demercuration, analogous to the similar procedures mentioned in... 

Alcohols and alkenes react with HN3 to give alkyl azides, which in the course... 

Treatment of alkenes with sodium azide, ferrous ion, and hydrogen... 

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