Réactions des Méthylazide et Phénylazide Avec Quelques Alcynes et Oléfines α‐Nitrées. Synthèse Régiospécifique des 1,2,3 Triazoles

Abstract

The reactions of alkynes and a-nitro-olefines with methylazide and phenylazide was studied. In contrast to known reactions with alkynes which are non-regioselective, methylazide and phenylazide react regiospecifically with a-nitro-olefines and give only one type of triazole after elimination of HN02. These reactions are very useful synthetic approaches to 1,2,3 triazoles.Les 1,2,3 triazoles ont fait I'objet de nombreux

One‐Pot Facile Synthesis of 1,5‐Disubstituted Triazolyl Glycoconjugates from Nitrostyrenes

“…Although a detailed investigation is required to established the exact mechanism leading to 1,5‐disubstituted‐1 H ‐1,2,3‐triazole, however, a probable mechanism for this ammonium salt catalyzed [3+2] cycloaddition reaction is presented in Scheme . As reported previously, the first‐step involved in regioselective 1,3‐dipolar cycloaddition of azide with nitro‐olefin afforded triazoline intermediate. Presumably the ammonium salts accelerate the cycloaddition reaction by increasing the electrophilicity of the nitroolefin through a weak ionic bond with oxygen atoms of nitro group and ammonium ions.…”

“…Therefore, to avoid the acid sensitive spoil with utilized protocol, we search for suitable alternative of p ‐TsOH. Through the available literature, we motivated to initiate the reaction with ammonium salts because of their weaker acidic nature in polar solvents and also active involvement in [3+2] cycloaddition reactions of nitrostyrenes and NaN 3 . We screened different catalysts for the reaction of 5 a with 6 a in anhydrous DMF (Table ).…”

“…In addition, less concentration has also been paid to scrutinize [3+2] cycloaddition reactions of organic azides with nitrostyrene. The reaction proceed with sluggish rate and requires long time duration at room temperature and moreover typically afforded mixture of products when carried out in absence of catalysts . Initially, such cycloaddition reactions were utilized for synthesis of NH ‐1,2,3‐triazole derivatives via reaction of nitro‐olefins with NaN 3 and TMsN 3 , although soon after further modifications on similar reaction have also been made towards the synthesis of 1,5‐disubstituted‐1 H ‐1,2,3‐triazoles (Scheme ) …”

Chemistry of 2-aryl-1-cyano-1-nitroethenes. Part II. Chemical transformations

“…Finally, 1-aryl-5(4)-phenyl-1H-1,2,3-triazole-4(5)-carbonitriles (4a,b, 6a,b) (Table 1) were formed as a result of spontaneous nitrous acid extrusion from primary [2,3] cycloaddition products [7]. Piet et al [12] also deal with the [2+3] cycloaddition reactions of PCN (1) with phenylazide (2a) and methylazide (7). They obtained 1-methyl-5-phenyl-1H-1,2,3-triazole-4-carbonitrile (9) and 1-methyl-4-phenyl-1H-1,2,3-triazole-5-carbonitrile as a result (11).…”

Aryl(hetaryl)-containing gem-cyanonitroethenes: Synthesis, structure, and reactions with 2,3-dimethyl-1,3-butadiene

“…Their reactions with 1,3-dipoles [7,[38][39][40][41][42] and vinyl ethers [43][44][45] yielding practically important cyclic compounds are of the particular interest.…”