A DFT study on the (2 + 3) cycloaddition reactions of 2‐nitropropene‐1 with Z‐C, N‐diarylnitrones

Abstract

ski a B3LYP/6-31G * calculations for competing (2 R 3)-cycloaddition pathways for 2-nitropropene-1 (1) to Z-C,N-diarylnitrones (2a-e) suggest a concerted reaction mechanism. However, the results point to the strongly asymmetric nature of transition complexes. Increasing polarity of the reaction environment and presence of electron-donating substituents in the nitrone phenyl rings contribute to the higher asymmetry of these structures.

Synthesis and Properties of Azoles and Their Derivatives. Part 70. Nitroallylic Systems in [2 + 3] Cycloaddition Reactions with Nitrones: A DFT Computational Study

“…The reaction pathways of the [2 + 3] cycloadditions were tested using the B3LYP/6‐31g(d) theoretical level . A similar approach was found to be appropriate for a number of nitrone [2 + 3] cycloadditions .…”

“…Although the chemistry of conjugated nitroalkenes has seen intensive development and is relatively well known with detailed data about the regiochemistry, stereochemistry, kinetics, and mechanisms of the [2 + 3] cycloadditions of conjugated nitropropenes ( 1 , 2 , 3 ) to acyclic di‐substituted and tri‐substituted nitrones and cyclic nitrones to be found in the literature, much less is known about the chemical properties of nitroallyls: there are only two reports in the literature for the [2 + 3] cycloaddition of 3‐nitroprop‐1‐ene ( 4 ) with nitrones. These concern the regiochemistry of the reaction of the nitroalkene 4 with C , C , N ‐triphenylnitrone ( 5 ).…”

“…To fill the existing gap and cast some light on the nature of [2 + 3] cycloadditions, we performed quantum chemical studies of a series of model processes involving 3‐nitroprop‐1‐enes with varying degrees of double‐bond shielding ( 4 and 7 , 8 ) and three arylnitrones ( 5 and 9 , 10 ), whose [2 + 3] cycloadditions with nitrovinyl systems have recently been thoroughly studied both theoretically and in the laboratory . …”

Acyclic and cyclic nitrone cycloadditions to 1-cinnamoyl-1-piperidine: A DFT study

“…Jasiński et al 49 reported the application of bond development indices I C3ÀC4 and I C5ÀO1 calculated by the relations…”

Synthesis and properties of azoles and their derivatives. 68.* [2+3] cycloaddition of 2-nitro-1-propene to (Z)-C,N-diphenylnitrone relative to AM1 and AM1/COSMO quantum-chemical calculations

“…However, in the case of strong electrophilic alkenes or considerable shielding of one of the reaction sites, a stepwise mechanism involving formation of a dipolar intermediate may compete with the concerted mechanism [3,4]. In this regard, in a continuation of a study of the mechanism of (4+2) -electron cycloadditions [5][6][7][8][9][10][11], we investigated the reaction pathways of the [2+3] cycloaddition of 2-nitro-1-propene (1) to (Z)-C,N-diphenylnitrone (2). The formation of four regioisomeric and stereoisomeric diarylnitroisoxazolidines 3-6 is possible in the reaction.…”