Alkynes sodium azide

Keywords Alkyl halides, alkynes, sodium azide, CU2O, methanol, room temperature, multi-component reaction, click synthesis, heterocycles, substituted 5-alkynyl 1,2,3-triazoles... 

A microwave-assisted three-component reaction has been used to prepare a series of 1,4-disubstituted-1,2,3-triazoles with complete control of regiose-lectivity by click chemistry , a fast and efficient approach to novel functionalized compounds using near perfect reactions [76]. In this user-friendly procedure for the copper(l) catalyzed 1,3-dipolar cycloaddition of azides and alkynes, irradiation of an alkyl halide, sodium azide, an alkyne and the Cu(l) catalyst, produced by the comproportionation of Cu(0) and Cu(ll), at 125 °C for 10-15 min, or at 75 °C for certain substrates, generated the organic azide in situ and gave the 1,4-disubstituted regioisomer 43 in 81-93% yield, with no contamination by the 1,5-regioisomer (Scheme 18). 

Another important click reaction is the cycloaddition of azides. The addition of sodium azide to nitriles to give l//-tetrazoles is shown to proceed readily in water with zinc salts as catalysts (Eq. 11.71).122 The scope of the reaction is quite broad a variety of aromatic nitriles, activated and nonactivated alkyl nitriles, substituted vinyl nitriles, thiocyanates, and cyanamides have all been shown to be viable substrates for this reaction. The reaction of an arylacetylene with an azide in hot water gave 1,4-disubstituted 1,2,3-triazoles in high yields,123 while a similar reaction between a terminal aliphatic alkyne and an azide (except 111 - nitroazidobenzcnc) afforded a mixture of regioisomers with... 

A three-component coupling was used to prepare a series of 1,4-disubstituted-l,2,3-triazoles 129 from the corresponding acetylated Baylis-Hillman adducts 127, sodium azide and terminal alkynes 128 <06TL3059>. This same reaction was also carried out in either water or in... 

Finally, Lecomte and coworkers reported the synthesis of mikto-arm star-shaped aliphatic polyesters by implementing a strategy based on click chemistry (Fig. 36) [162]. Firstly, the polymerization of sCL was initiated by a diol bearing an alkyne function. The chain-ends were protected from any further undesired reaction by the esterification reaction with acetyl chloride. The alkyne was then reacted with 3-azidopropan-l-ol. The hydroxyl function located at the middle of the chain was then used to initiate the ROP of sCL and y-bromo-s-caprolactone. Finally, pendant bromides were reacted successfully with sodium azide and then with N, N-dimethylprop-2-yn-l-amine to obtain pendant amines. Under acidic conditions, pendant amines were protonated and the polymer turned out to exhibit amphiphilic properties. 

Acetoxylation. Transformations of Carbonyl Compounds. Phenolic Oxidation. Oxidation of Nitrogen Compounds. Hypervalent iodine Reagents in Combination with Azido Compounds. DIB and Sodium Azide in Combination with Other Reagents. Transformations of Alkynes Involving Thiophenols and Diphenyl Diselenide. Miscellaneous Reactions. 

Iron(n) salts mediated the coupling of trialkylboranes with KSGN to give RSCN via a radical process.553,554 Stereochemically pure ( )-l-thiocyanato-alkenes or ( )-l-azide-alkenes were obtained from alkynes when hydro-boration with disiamylborane was followed by reaction with potassium thiocyanate or sodium azide in the presence of copper(n) nitrate, copper(n) acetate, and small amount of water in polar aprotic solvent (Equation (116)).555... 

Free amino carboxylic acids and their ester derivatives can be added to fluoroalkylatcd alkynes to give amino acid derivatives. Fluoroalkynes and sodium azide afford, after thermal decomposition, the corresponding aziridincs. ... 

The hazardous nature (see Tetrazoles below) of some alkyl azides limits the method in these cases, however A-alkyl- (benzyl) -1,2,3-triazoles can be obtained by preparing the azide in situ, for example using a mixture of sodium azide, the alkyne and a benzyl hahde in situ preparation of aryl azides is also feasible. An alternative method in which the alkyl azide is also generated in situ, is to use a diazo transfer to a primary amine the diazo transfer requires Cu(II) and the cycloaddition needs Cu(I) so a reducing agent is added together with the alkyne following the first phase. ... 

COPPER (7440-50-8) Cu The powder forms the friction-, heat-, or shock-sensitive explosive detonator, copper acetylide, with acetylene gas acetylenic compounds and ethylene oxides. The powder forms explosive materials with azides (e.g., sodium azide forms potentially explosive copper azide). Finely divided material forms friction-, heat-, or shock-sensitive explosive with powdered divided bromates, chlorates, and iodates of barimn, calcimn, magnesium, potassium, sodium, or zinc. Violent reaction, possibly explosive, when finely dispersed powder comes in contact with strong oxidizers ammonium nitrate alkynes, bromine vapor, calcium carbide, chlorine, ethylene oxide, hydrazine mononitrate, hydrogen peroxide, hydrogen sulfide, finely divided bromates, iodine, lead azide, potassium peroxide, sodium peroxide (incandescence), sulfuric acid. Incompatible with acids, anhydrous ammonia chemically active metals such as potassium, sodium, magnesium, and zinc, zirconium, strong bases. 

This may be attributed to the spatial proximity of the azide and alkyne substituents enforced by the bulky side chain. After successfully synthesizing amino acid derived fused triazoles 6a-g, 8a, and 8b, we decided to extend the scope of this methodology by varying the alkyl, as well as the acyl components, which may furnish other triazole-fused heterocycles. Accordingly, compound la was treated with chloromethane sulfonyl chloride in the presence of triethylamine to furnish chlorosulfonamide derivative 7c in moderate yield (60%). Compound 7c was then treated with an excess amount of sodium azide in DMF at 100 °C. 

Click chemistry has been used to prepare a series of l,4-disubstituted-l,2,3-triazoles by a Cu(I)-catalyzed three-component reaction of alkyl halides, sodium azide, and alkynes. The method avoids isolation and handling of potentially unstable small organic azides and provides triazoles in the pure form and high yields (81-89%). Microwave irradiation dramatically reduces reaction times from hours to minutes [50]. 

Eokin and Van der Eycken, et al. also described the microwave-assisted three-component one-pot synthesis of 1,4-disubstituted-l,2,3-triazoles 211 (Scheme 11.53) [109]. A suspension of alkyl halides 208, sodium azide 209, and alkynes 210 in a 1 1 mixture of t-BuOH and water, together with a copper catalyst, in a... 

The 1,2,3-triazoles have interesting biological properties [86, 87]. 1,4-Disubstituted triazoles 45 can be synthesized in a one-pot three-component MW-assisted reaction from corresponding alkyl halides, sodium azide, and alkynes (Scheme 17.34) [88]. 

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