A DFT study of the mechanism and selectivities of the [3 + 2] cycloaddition reaction between 3‐(benzylideneamino)oxindole and trans‐β‐nitrostyrene

Abstract

The mechanism and regioselectivities and stereoselectivities of the [3 + 2] cycloaddition (32CA) reaction of 3-(benzylideneamino) oxindole (AY) and trans-βnitrostyrene have been studied using both B3LYP and ωB97XD density functional theory methods together with the standard 6-31G(d) basis set. Four reactive pathways associated with the ortho and meta regioselective channels and endo and exo stereoselective approaches modes have been explored and characterized. While the B3LYP functional fails to predict the experimental regioselectivity, the ωB97XD one succeeds to predict the experimentally observed meta regioselectivity favoring the formation of meta/endo cycloadduct as the major isomer. Inclusion of solvent effects increases the regioselectivity and decreases the experimentally observed stereoselectivity. Analysis of the density functional theory global reactivity indices and the Parr functions of the reagents in its ground state allows explaining the reactivity and the meta regioselectivity of this zwitterionic-type 32CA reaction, which account for the high polar character of this reaction. Non-covalent interaction analysis of the most favorable meta/endo transition state structure reveals that the formation of a hydrogen-bond between 1 nitro oxygen and the AY N-H hydrogen is responsible for the selectivity experimentally found in this polar zwitterionic-type 32CA reaction.

Theoretical investigation on facial and stereoselectivity in Diels‐Alder cycloadditions of maleic anhydride to dissymmetric cage‐annulated cyclohexa‐1,3‐dienes

“…The value of GEDT is 0.19e at TS I, 0.15e at TS II, 0.18e at TS III, and 0.15 at TS IV, therefore indicating that all processes have some polar character. Consequently, the polarities of TS I and TS III pathways are slightly higher than that of TS II and TS IV on the basis of the principle, in which the larger the GEDT at TS is, the more polar reaction, and further the higher GEDT at TS results in a decrease of the activation barrier of the DA reaction . On the other hand, the steric interactions between carboxylate groups in MA and chlorine substituents in TDPDD at TS I and between carboxylate groups in MA and carbonyl groups in TDPDD at TS II may account for the large asynchronicities at these exo TS; even, these interactions may probably have increased the activation barriers of the corresponding TSs (see Figure ).…”

The influence of axial ligands on the catalytic activity and enantioselectivity of salen‐Mn complexes in the asymmetric epoxidation

“…The B3LYP method based on density functional theory can well reproduce the crystal structure [41][42][43] and other experimental data [44,45,61] of salen-metal complexes. Hence, this theoretic method has been widely used for calculation of the salen-Mn system [46][47][48][49][50][51][52][53][54][55][56][57][58][62][63][64][65] and other organometallic compounds. [66][67][68] Previous researches have compared the B3LYP method with B3LYP* hybrid function [69] for the salen-Mn and found that the B3LYP* values are in better quantitative agreement with B3LYP values comparing with BP86 and BLYP methods.…”

“…Many theoretic researches adopted a simplified model to simulate the Jacobsen catalyst ( Figure 1A). [46][47][48][49][50][51][52][53][54][55][56][57] This simple model works well for investigating the electric structure of the active center. As we know, the steric hindrance is vital for the enantioselectivity.…”

“…[59] The reaction barrier catalyzed by singlet salen-Mn is far higher than that catalyzed by triplet or quintet one. [52,55,57,[60][61][62][63] Hence, we mainly focused on the reactions catalyzed by triplet and quintet catalysts. Both the (R, S) and (S, R) approach reactions were taken into consideration ( Figure 1C).…”

Me3SiBr/InCl3 catalyzed allylation of alcohols: Identifying the combined Lewis structure and investigating the reaction mechanism

“…[22][23][24][25][26][27][28] All the geometries including reactants, intermediates, transition states, and products were obtained at ωB97XD/def2-SVP theory level. [29][30][31] ωB97XD is range-separated functional, which can obtain satisfactory accuracy for thermochemistry, kinetics, and noncovalent interactions and be used for reaction mechanism research [32][33][34][35][36] with def2-SVP basis set. [37][38][39] The calculation used solvent model SMD, [40][41][42] and hexane was taken as the solvent.…”