Evidence for the encounter complex in frustrated Lewis pair chemistry

Dalton Transactions, Journal Year: 2022, Volume and Issue: 51(28), P. 10681 - 10689

Published: Jan. 1, 2022

The encounter complex underpins small-molecule activation and catalysis by frustrated Lewis pairs. This article explores the variety of computational experimental techniques that have probed this ephemeral species.

Language: Английский

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Lewis Acid-Catalyzed Carbonyl-Ene Reaction: Interplay between Aromaticity, Synchronicity, and Pauli Repulsion

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(15), P. 11102 - 11110

Published: July 24, 2023

The physical factors governing the catalysis in Lewis acid-promoted carbonyl-ene reactions have been explored detail quantum chemically. It is found that binding of a acid to carbonyl group directly involved transformation greatly accelerates reaction by decreasing corresponding activation barrier up 25 kcal/mol. makes process much more asynchronous and transition state less in-plane aromatic. remarkable acceleration induced catalyst ascribed, means strain model energy decomposition analysis methods, mainly significant reduction Pauli repulsion between key occupied π-molecular orbitals reactants not widely accepted stabilization LUMO enophile.

Language: Английский

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Origins of Regioselectivity in CuH-Catalyzed Hydrofunctionalization of Alkenes

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(5), P. 2750 - 2757

Published: Feb. 15, 2023

Factors controlling the regioselectivity in alkene hydrocupration were computationally investigated using energy decomposition analysis. The results demonstrate that Markovnikov-selective with electronically activated mono-substituted olefins is mostly affected by destabilizing Pauli repulsion, which due to electron delocalization effect. anti-Markovnikov-selective 1,1-dialkyl-substituted terminal dominated repulsive electrostatic interactions, because of unequal π distribution caused induction effect alkyl substituents.

Language: Английский

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B(C₆F₅)₃-Catalyzed [4 + 2] Cyclization Strategy: Synthesis and Photophysical Properties of 5H-Naphtho[2,3-c]carbazole-8,13-dione Derivatives

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(5), P. 2703 - 2713

Published: Feb. 17, 2023

In this paper, a series of novel carbazolequinones were efficiently obtained by B(C6F5)3-catalyzed [4 + 2] cyclization reaction. This protocol not only had simple operation, broad substrate range, and high atomic economy, but also low catalyst loading avoided using metal catalysts. addition, we constructed diverse new carbazole-fused compounds under different reduction conditions. The results photophysical characterization showed that the structure derivatives significant impact on fluorescence properties.

Language: Английский

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Unraveling the Bürgi-Dunitz Angle with Precision: The Power of a Two-Dimensional Energy Decomposition Analysis

Journal of Chemical Theory and Computation, Journal Year: 2023, Volume and Issue: 19(20), P. 7300 - 7306

Published: Oct. 4, 2023

Understanding the geometrical preferences in chemical reactions is crucial for advancing field of organic chemistry and improving synthetic strategies. One such preference, Bürgi-Dunitz angle, central to nucleophilic addition involving carbonyl groups. This study successfully employs a novel two-dimensional Distortion-Interaction/Activation-Strain Model combination with Energy Decomposition Analysis investigate origins angle reaction CN- (CH3)2C═O. We constructed 2D potential energy surface defined by distance between nucleophile carbonylic carbon atom attack followed an in-depth exploration components, including strain interaction energy. Our analysis reveals that emerges from delicate balance two key factors: High energy, as result compound distorting avoid Pauli repulsion, encountered at high angles, thus setting upper bound. On other hand, shaped dominant repulsion when angles are lower. work emphasizes value refined tool, offering both quantitative qualitative insights into reactivity selectivity.

Language: Английский

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Computational study of polyhomologation: understanding reactivity with B, Al, and Ga

New Journal of Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

In the polyhomologation, there is a higher reactivity (lower energy barrier) of boron toward Corey's ylide, in comparison to aluminum and gallium.

Language: Английский

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Influence of the Nature of Group 15 Element on [Au^I]–C≡E/Azide 1,3-Dipolar Cycloaddition Reaction

Inorganic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 11, 2025

The impact of the nature Group 15 element on both bonding situation and reactivity gold(I)-C ≡ E (E = N to Bi) complexes has been studied quantum chemically within density theory functional framework. For this purpose, 1,3-dipolar cycloaddition reaction involving tBuN3 as dipole selected its main features, including regioselectivity transformation in-plane aromaticity corresponding transition structures, have investigated. It is found that increased one moves down (N ≪ P < As Sb Bi). This trend rationalized by using combined activation strain model energy decomposition analysis methods, which indicate process mainly dominated required reactants reach state geometries.

Language: Английский

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Borane derivatives of five-membered N-heterocyclic rings as frustrated Lewis pairs: activation of CO2

Structural Chemistry, Journal Year: 2023, Volume and Issue: 34(4), P. 1591 - 1601

Published: May 6, 2023

Abstract The reaction of seventeen borane derivatives five-membered N-heterocyclic rings (BNHRs) with CO 2 has been studied by means DFT calculations. Several non-covalent complexes between the BNHRs and which evolve through a TS in single adduct for each BNHR have identified. calculated IRC allowed to identify complex involved case. stationary points reactions analyzed distortion/interaction partition model. In addition, empirical models attempted correlate acid (fluoride ion affinity) basic (proton properties isolated barriers energies. energetics are influenced number nitrogen atoms ring.

Language: Английский

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Mechanism and Origin of Regioselectivity in the Phosphine-Catalyzed Heine Reaction

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

Published: May 7, 2025

Herein, we present a comprehensive computational study of the reaction mechanism and regioselectivity patterns phosphine-catalyzed Heine involving N-benzoylaziridines. Density functional theory (DFT) calculations reveal that process takes place under kinetic control, favoring formation corresponding 4-substituted oxazoline derivatives. Conformational analysis indicates predominantly populated ground-state conformation aziridine does not represent kinetically active species. Exploration conformational space in transition state (TS) region shows preferred pathway for nucleophilic ring-opening involves TS structure where benzoyl moiety adopts nearly coplanar arrangement. Furthermore, main factors controlling observed as well impact substituents on reactivity, are quantitatively rationalized using activation strain model reactivity combination with energy decomposition analysis.

Language: Английский

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Structural Snapshots of Reversible Carbon Dioxide Capture and (De)oxygenation at Group 14 Diradicaloids

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 8, 2024

Although diradicals should exhibit a rather small reaction barrier as compared to closed-shell species for activating kinetically inert molecules, the activation and functionalization of carbon dioxide with stable main-group remain virtually unexplored. In this work, we present thorough study on CO2 activation, reversible capture, (de)oxygenation mediated by Group 14 singlet (i.e., diradicaloids) [(ADC)E]2 (E = Si, Ge, Sn) based an anionic dicarbene (ADC) framework (ADC PhC{N(Dipp)C}2; Dipp 2,6-iPr2C6H3). readily undergo [4 + 2]-cycloadditions result in barrelene-type bis-metallylenes [(ADC)E]2(OC═O). The addition is E Ge; thus, detaches under vacuum or at elevated temperature regenerates [(ADC)Ge]2. [(ADC)Sn]2(OC═O) isolable but deoxygenates additional form [(ADC)Sn]2(O2CO) CO. [(ADC)Si]2(OC═O) extremely reactive could not be isolated detected it spontaneously reacts further yield elusive monomeric Si(IV) oxides [(ADC)Si(O)]2(COn) carbonates [(ADC)Si(CO3)]2(COn) (n 1 2) via CO2. molecular structures all compounds have been established X-ray diffraction, mechanistic insight their formation has suggested DFT calculations.

Language: Английский

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