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

---

Theoretical insight of reactive oxygen species scavenging mechanism in lignin waste depolymerization products

RSC Advances, Journal Year: 2024, Volume and Issue: 14(9), P. 6310 - 6323

Published: Jan. 1, 2024

Syringol derivatives outperform phenolic antioxidants in non-polar solvents. HT mechanism is the favoured to scavenge hydroperoxyl radical substituted syringols. Based on ASM analysis, hydrogen bond key factor increasing both strain and interaction energy.

Language: Английский

---

Backside versus Frontside SN2 Reactions of Alkyl Triflates and Alcohols

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(25)

Published: Feb. 22, 2024

Nucleophilic substitution reactions are elementary in organic chemistry that used many synthetic routes. By quantum chemical methods, we have investigated the intrinsic competition between backside S

Language: Английский

---

Origin of the α‐Effect in S_N2 Reactions

Angewandte Chemie, Journal Year: 2021, Volume and Issue: 133(38), P. 21008 - 21016

Published: June 4, 2021

Abstract The α‐effect is a term used to explain the dramatically enhanced reactivity of α‐nucleophiles (R−Y−X: − ) compared their parent normal nucleophile (R−X: by deviating from classical Brønsted‐type reactivity‐basicity relationship. exact origin this effect is, however, still heavily under debate. In work, we have quantum chemically analyzed set anionic nucleophiles, including O ‐, N ‐ and S ‐based α‐nucleophiles, participating in an 2 reaction with ethyl chloride using relativistic density functional theory at ZORA‐OLYP/QZ4P. Our activation strain Kohn–Sham molecular orbital analyses identified two criteria α‐nucleophile needs fulfill order show α‐effect: (i) small HOMO lobe on nucleophilic center, pointing towards substrate, reduce repulsive occupied–occupied overlap hence (steric) Pauli repulsion substrate; (ii) sufficiently high energy overcome loss favorable HOMO–LUMO as consequence first criterion, reducing gap. If one these not fulfilled, can expect no or inverse α‐effect.

Language: Английский

---

C−X Bond Activation by Palladium: Steric Shielding versus Steric Attraction

Chemistry - A European Journal, Journal Year: 2022, Volume and Issue: 28(44)

Published: April 14, 2022

The C-X bond activation (X = H, C) of a series substituted C(n°)-H and C(n°)-C(m°) bonds with C(n°) C(m°) H

Language: Английский

---