Mechanisms and Origins of Regio- and Stereoselectivities in NHC-Catalyzed [3 + 3] Annulation of α-Bromoenals and 5-Aminoisoxazoles: A DFT Study DOI

Mingchao Zhang,

Zhiqiang Zhang, Yan Li

et al.

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(15), P. 10748 - 10759

Published: July 12, 2024

Density functional theory (DFT) calculations were conducted to explore the mechanisms and origins of regio- stereoselectivities underlying [3 + 3] annulation reaction between α-bromoenals 5-aminoisoxazoles with

Language: Английский

Mechanism and Origin of Stereoselectivity for the NHC-Catalyzed Desymmetrization Reaction for the Synthesis of Axially Chiral Biaryl Aldehydes DOI
Xiaoxiao Hou, Donghui Wei

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(5), P. 3133 - 3142

Published: Feb. 15, 2024

Organocatalytic desymmetrization reaction is a powerful tool for constructing axial chirality, but the theoretical study on origin of stereoselectivity still lags behind even now. In this work, N-heterocyclic carbene (NHC)-catalyzed biaryl frameworks synthesis axially chiral aldehydes has been selected and theoretically investigated by using density functional theory (DFT). The fundamental pathway involves several steps, i.e., desymmetrization, formation Breslow oxidation, esterification, NHC regeneration. processes have identified as stereoselectivity-determining rate-determining steps. Further weak interaction analyses proved that C–H···O hydrogen bond C–H···π interactions are responsible stability key stereoselective transition states. This research contributes to understanding nature NHC-catalyzed reactions compounds.

Language: Английский

Citations

14
Mechanistic studies on an isothiourea-catalyzed reaction of an aromatic ester with an imine DOI

Meng-Qing Yang,

Yang Wang

Molecular Catalysis, Journal Year: 2024, Volume and Issue: 567, P. 114445 - 114445

Published: Aug. 10, 2024

Language: Английский

Citations

4
Mechanisms of C(sp3)-H Functionalization of Acetonitrile or Acetone with Alkynes: A DFT Investigation DOI
Bin Chen,

Tiantian Feng,

Da‐Gang Zhou

et al.

Journal of Chemical Information and Modeling, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 6, 2025

The mechanisms for the C(sp3)-H activation and addition reactions between acetonitrile (or acetone) alkynes have been investigated with M06-2X-D3/ma-def2-TZVP method basis set. SMD (solvation model based on solute electron density) was applied to simulate solvent effect. In first second reactions, 2-phenylbut-3-yn-2-ol reacted acetone, respectively. First, activations of acetone could be achieved by PhCOO• t-BuO• radicals. Then, converted into final products P1 P2. Gibbs free energy surfaces these two suggest that blue lines would favorable paths lower barriers, terminal C atom C≡C bond is best reactive site. Moreover, analysis IRI (Interaction Region Indicator) reveals Z- E-configuration transformations. While in third fourth methyl(2-(phenylethynyl)phenyl)sulfane has interactions via some paths, profiles show C10 atom, rather than C11 priority, are favorable. Furthermore, action mode Na2HPO4 reduce barrier benefit reaction. vdW (van der Waals) play an important role choice fifth sixth) reaction, it happened 1-(2-(methylthio)phenyl)-3-phenylprop-2-yn-1-one acetontrile yield product P5 P6). computational results uncovered line path, site depends interactions, which origin selectivity. addition, investigation byproducts carried out, can explain reason only main produced. Both those agree experimental results. localized orbital locator (LOL) isosurfaces, Laplacian order (LBO), density critical point (ρBCP), spin isosurface graphs, graphs used analyze structure reveal reaction substances.

Language: Английский

Citations

0
Mechanism and Origins of Regio- and Stereoselectivities of NHC-Catalyzed Dearomative Annulation of Benzoazoles and Cinnamaldehydes from DFT DOI
Yan Li,

Yanlong Kang,

Junjie Xiao

et al.

The Journal of Physical Chemistry A, Journal Year: 2025, Volume and Issue: unknown

Published: March 5, 2025

A theoretical study on the mechanism, regioselectivity, and enantioselectivity of NHC-catalyzed dearomatizing annulation benzoxazoles with enals has been conducted using density functional theory calculations. Our calculated results indicate that favored mechanism occurs through eight reaction steps: initial binding NHC to enals, followed by formation Breslow intermediate via proton transfer. Subsequent oxidation generates α,β-unsaturated acylazolium intermediate, which can undergo Michael addition benzoxazoles. Sequential protonation/deprotonation/cyclization produces six-membered cyclic undergoes catalyst elimination, leading final product. DABCO·H+ was found play important roles in transfer cyclization. Without DABCO·H+, energy barrier up 44.2 kcal/mol for step 2 is too high be accessible. With corresponding value lowered 18.6 kcal/mol. The cyclization 7.4 DABCO·H+. determines both regioselectivity. According NCI analysis, controlled strong interactions (such as C-H···O, C-H···N, π···π) between We also discuss solvent substituent effects role NHC. mechanistic insights obtained present would help improving current systems or designing new synthetic routes.

Language: Английский

Citations

0
Chiral phosphoric acid (CPA)-catalyzed transformation reaction of ketene: Competing mechanisms and origin of regio- and stereoselectivities DOI
Han Zhang, Keyuan Zhao, Donghui Wei

et al.

Molecular Catalysis, Journal Year: 2024, Volume and Issue: 560, P. 114150 - 114150

Published: April 16, 2024

Language: Английский

Citations

3
Activation Model and Origins of Selectivity for Chiral Phosphoric Acid Catalyzed Diradical Reactions DOI
Ying Wang,

Weichi Chen,

Yilei Lai

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(43), P. 23527 - 23532

Published: Oct. 3, 2023

To develop new radical synthesis strategies, a profound understanding of the electronic transfer mechanism is critical. An activation model called relayed proton-coupled electron (relayed-PCET) was developed and investigated for chiral phosphoric acid-catalyzed diradical reactions by density functional theory (DFT). The driving force from nucleophile to electrophile proton that occurs via acid (CPA) catalyst electrophile. Moreover, origins selectivity can be explained distortion catalyst, favorable hydrogen bonding, strong interactions substrates with substituents CPAs.

Language: Английский

Citations

9
Both N-F oxidant and NaF determined reaction yield in the organoselenium-catalyzed oxidative ring-closing reaction of unsaturated alcohol: A theoretical study DOI
Chao-Xian Yan,

Lei-Tao Wei,

Weiqin Gao

et al.

Molecular Catalysis, Journal Year: 2024, Volume and Issue: 567, P. 114442 - 114442

Published: Aug. 13, 2024

Language: Английский

Citations

2
Mechanisms, regio- and stereoselectivities involved in NHC catalyzed dearomatizing annulation of ester with ylide: A computational study DOI
Yan Li, Junjie Xiao,

Yanlong Kang

et al.

Molecular Catalysis, Journal Year: 2024, Volume and Issue: 560, P. 114146 - 114146

Published: April 16, 2024

Language: Английский

Citations

1
A DFT study of NHC-catalyzed reactions of [3+3] annulations of 2-bromoenals and thioamides: mechanisms and regio- and stereoselectivities DOI
Yan Li,

Lina Geng,

Zhiyi Song

et al.

New Journal of Chemistry, Journal Year: 2023, Volume and Issue: 47(47), P. 21815 - 21824

Published: Jan. 1, 2023

The mechanisms and regio- stereoselectivities of NHC-catalyzed [3+3] annulations 2-bromoenals thioamides are investigated.

Language: Английский

Citations

2
A Theoretical Study on Organoselenium-Catalyzed Exo-Selective Oxidative Ring-Closing Reaction Promoted by 3 Different N-F Oxidants: Active Catalytic Species Screening, Reaction Mechanism, Origin of Exo-/Endo- and (E)-/(Z)- Selectivities, and the Influence of Different Reagents on Reaction Yields DOI
Chao-Xian Yan,

Lei-Tao Wei,

Weiqin Gao

et al.

Published: Jan. 1, 2024

Language: Английский

Citations

0