Cycloaddition des Méthylazide et Phénylazide au β‐Nitrostyrène et au Nitropropène Homologue

Abstract

Phenylazide and methylazide reacts with title olefines and gives two isomeric triazoles without nitro group, and 4-nitro-l,2,3 triazole. The isomerisation of starting alkenes explains the formation of isomeric triazoles. Oxydation of amino-nitro-diazocompounds in equilibrium with 1,2,3 triazolines leads to 4-nitro-l,2,3 triazoles.

Thermal [3+2] cycloaddition reactions as most universal way for the effective preparation of five-membered nitrogen containing heterocycles

“…So, the methyl azide reacts rapidly with the E-1-nitroprop-1-ene in fully regioselective manner yielding 3,4-dimethyl-5-nitrotriazoline. The obtained product exhibits relatively low stability and convert easily to aromatic triazole system via dehydronitration / rearrangement sequence [58].…”

Understanding the different reactivity of (Z)- and (E)-β-nitrostyrenes in [3+2] cycloaddition reactions. An MEDT study

“…9 Some nitroethylenes can exist as transitory unstable (Z)-isomeric form. [10][11][12][13][14][15][16] These structures have shown to have some tendency to gradually transform into the (E)-isomers.…”

“…In particular, only some minor mentions regarding the participation of (Z)-nitroethylenes in [3+2] cycloaddition (32CA) reactions can be found in the literature. 13,16 Gandol and coworkers 16 studied the course of 32CA reactions of (E)-b-nitrostyrene (E)-1 and (Z)-b-nitrostyrene (Z)-1 with 5,5-dimethylpyrroline-N-oxide 2, a ve-membered cyclic nitrone, in benzene, under kinetic control conditions (see Scheme 1). They found that the 32CA reaction involving bnitrostyrene (E)-1 gave isoxazolidine trans-3 in a 72% yield, together with isoxazolidine cis-4.…”

“…In particular, only some minor mentions regarding the participation of ( Z )-nitroethylenes in [3+2] cycloaddition (32CA) reactions can be found in the literature. 13,16 …”

Understanding the molecular mechanism of γ‐elimination of nitrous acid in the framework of the molecular electron density theory

“…The migration of the nitro group in reactions plays an important role in the processes of transformation of organic compounds. Within this class of reactions, besides the nitro group rearrangement realized via [1.3]‐ 1,2 or [1.5]‐sigmatropic shift mechanisms, 3–6 many examples of nitrous acid extrusion were described. Most of these reactions proceed according to the β‐elimination scheme.…”