scholarly journals Understanding the mechanism of the chiral phosphoric acid-catalyzed aza-Cope rearrangement

2021 ◽  
Author(s):  
Bruno N. Falcone ◽  
Matthew N. Grayson
Keyword(s):  
Density Functional Theory ◽  
Phosphoric Acid ◽  
Density Functional ◽  
Reaction Pathway ◽  
Cope Rearrangement ◽  
Functional Theory ◽  
Chiral Phosphoric Acid ◽  
Acid Catalyzed

Using Density Functional Theory, the mechanism of the enantioselective phosphoric acid-catalyzed aza-Cope rearrangement was investigated. Stabilization of the preferred reaction pathway was rationalized by studying the non-bonding interactions between substrate and catalyst.

Role of keto–enol tautomerization in a chiral phosphoric acid catalyzed asymmetric thiocarboxylysis of meso-epoxide: a DFT study

2015 ◽  
Vol 13 (45) ◽  
pp. 10981-10985 ◽  
Author(s):  
Manjaly J. Ajitha ◽  
Kuo-Wei Huang
Keyword(s):  
Density Functional Theory ◽  
Phosphoric Acid ◽  
Dft Calculations ◽  
Density Functional ◽  
Dft Study ◽  
Functional Theory ◽  
Chiral Phosphoric Acid ◽  
Acid Catalyzed

The mechanism of a chiral phosphoric acid catalyzed thiocarboxylysis of meso-epoxide was investigated by density functional theory (DFT) calculations (M06-2X).

scholarly journals Chiral phosphoric acid-catalyzed stereodivergent synthesis of trisubstituted allenes and computational mechanistic studies

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiawen Wang ◽  
Sujuan Zheng ◽  
Subramani Rajkumar ◽  
Jinglei Xie ◽  
Na Yu ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Density Functional ◽  
Acid Catalysis ◽  
Chiral Molecules ◽  
Functional Theory ◽  
Chiral Phosphoric Acid ◽  
Acid Catalyzed ◽  
Asymmetric Additions ◽  
Formation Step ◽  
Stagger Form

Abstract Chiral molecules with multiple stereocenters are widely present in natural products and pharmaceuticals, whose absolute and relative configurations are both critically important for their physiological activities. In spite of the fact that a series of ingenious strategies have been developed for asymmetric diastereodivergent catalysis, most of these methods are limited to the divergent construction of point chirality. Here we report an enantioselective and diastereodivergent synthesis of trisubstituted allenes by asymmetric additions of oxazolones to activated 1,3-enynes enabled by chiral phosphoric acid (CPA) catalysis, where the divergence of the allenic axial stereogenicity is realized by modifications of CPA catalysts. Density functional theory (DFT) calculations are performed to elucidate the origin of diastereodivergence by the stacking- and stagger-form in the transition state (TS) of allene formation step, as well as to disclose a Münchnone-type activation mode of oxazolones under Brønsted acid catalysis.

Synthesis of novel N-functionalized 4-aryl-tetrahydrobiquinoline-2,5-(1H,3H)-diones via one-pot three-component reaction: a joint experimental and computational study

2018 ◽  
Vol 96 (12) ◽  
pp. 1071-1078
Author(s):  
Vahideh Zadsirjan ◽  
Sayyed Jalil Mahdizadeh ◽  
Majid M. Heravi ◽  
Masumeh Heydari
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Computational Study ◽  
Reaction Pathway ◽  
Deep Insight ◽  
One Pot ◽  
Functional Theory ◽  
Three Component Reaction ◽  
High Yields ◽  
Mechanism Of The Reaction

A novel series of N-functionalized 4-aryl-tetrahydrobiquinoline-2,5-(1H,3H)-diones were synthesized in high yields by a one-pot three-component reaction involving 2-chloroquinoline-3-carbaldehydes, Meldrum’s acid, and enaminones (dimedone-based enaminones) in the presence of K2CO3 in CH3CN under reflux condition. To gain a deep insight on the mechanism of the reaction, an extensive series of quantum mechanics calculations in the framework of density functional theory (DFT) were carried out for supporting the suggested reaction pathway.

scholarly journals Density Functional Theory Based Micro- and Macro-Kinetic Studies of Ni-Catalyzed Methanol Steam Reforming

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 349 ◽  
Author(s):  
Changming Ke ◽  
Zijing Lin
Keyword(s):  
Density Functional Theory ◽  
Steam Reforming ◽  
Density Functional ◽  
Reaction Pathway ◽  
Elementary Reaction ◽  
Main Reaction ◽  
Methanol Steam Reforming ◽  
Surface Species ◽  
Functional Theory ◽  
Microkinetic Model

The intrinsic mechanism of Ni-catalyzed methanol steam reforming (MSR) is examined by considering 54 elementary reaction steps involved in MSR over Ni(111). Density functional theory computations and transition state theory analyses are performed on the elementary reaction network. A microkinetic model is constructed by combining the quantum chemical results with a continuous stirring tank reactor model. MSR rates deduced from the microkinetic model agree with the available experimental data. The microkinetic model is used to identify the main reaction pathway, the rate determining step, and the coverages of surface species. An analytical expression of MSR rate is derived based on the dominant reaction pathway and the coverages of surface species. The analytical rate equation is easy to use and should be very helpful for the design and optimization of the operating conditions of MSR.

scholarly journals Graphdiyne based metal atomic catalysts for synthesizing ammonia

2020 ◽  
Author(s):  
Huidi Yu ◽  
Yurui Xue ◽  
Lan Hui ◽  
Chao Zhang ◽  
Yan Fang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electron Transfer ◽  
Density Functional ◽  
Reaction Pathway ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Faradaic Efficiency ◽  
Nitrogen Reduction ◽  
Strongly Coupled ◽  
Neutral Media

Abstract Exploring new catalysts for nitrogen reduction at ambient pressures and temperatures with ultrahigh ammonia (NH3) yield and selectivity is still a giant challenge. In this work, atomic catalysts with separated Pd atoms on graphdiyne (Pd-GDY) have been synthesized and show fascinating electrocatalytic properties for nitrogen reduction. Outstandingly, the catalyst shows the highest average NH3 yield of 4.45 ± 0.30 mgNH3 mgPd−1 h−1, almost tens of orders larger than previously reported ones, and 100% reaction selectivity in neutral media. And Pd-GDY exhibits almost no decreases in the NH3 yield and Faradaic efficiency. Density functional theory calculations show that the reaction pathway prefers to perform at the (Pd, C1, C2) active area due to the strongly coupled (Pd, C1, C2) which elevates the selectivity via enhanced electron-transfer. By adjusting the p-d coupling accurately, the reduction of self-activated nitrogen is promoted by anchoring atom selection, and the side effects are minimized.

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