Computational discoveries of reaction mechanisms: recent highlights and emerging challenges

Abstract

This review surveys the ways in which theoretical calculations have uncovered new insights into reaction mechanisms, illustrated by examples from three distinct fields of organic chemistry.

Mechanism of the Visible-Light-Promoted C(sp3)–H Oxidation via Uranyl Photocatalysis

“…Quantum computational chemistry plays an important role in the mechanism research today and provides numerous constructive suggestions including the confirmation of target structures, methodology development, and catalyst design. − Density functional theory (DFT) is a well-established and popular first-principle method in quantum chemistry, which has been extensively employed to investigate the mechanism of organic synthesis reactions, especially metal-catalyzed reactions. DFT calculations have been demonstrated to be reliable in revealing detailed potential energy surfaces and the geometric and electronic properties of reactants, products, intermediates, and transition states in various catalytic reactions. − In contrast to that of transition metals (e.g., Ru­(bpy) 3 2+ (bpy = 2,2′-bipyridine), − [Rh III (dtbbpy) 2 (I) 2 ] + (dtbbpy = 4,4′-di tert -butyl-2,2′-bipyridine) , ) involved in photocatalytic reactions, the theoretical study on the mechanism of the uranyl photocatalytic reaction is rare, especially for the important oxidation reaction of alkylbenzenes, ,, for which the oxidation products are pivotal for the production of many industrial products such as petrochemicals, pharmaceuticals, fragrance compounds, agrochemicals, etc.…”

Exploring borderline SN1–SN2 mechanisms: the role of explicit solvation protocols in the DFT investigation of isopropyl chloride

“…9,10 While extensive efforts have been devoted to unraveling the intricate effects of solvation in chemical processes, accounting for precise solvent effects into quantum simulations of chemical reactions remains a substantial challenge. 11–13 An efficient strategy to describe these processes at the atomic level combines explicit and implicit solvation methods. 14,15 There are two main methodologies for defining the solvent arrangement around a particular solute: top-down and bottom-up.…”

Bispericyclic Ambimodal Dimerization of Pentafulvene: The Origin of Asynchronicity and Kinetic Selectivity of the Endo Transition State

“…7−9 Theoretical simulation aided by experimental evidence is the inexpensive and best-determining tool for the fundamental understanding of the reaction mechanisms. 1,5,6,8,10,11 Conventionally, a chemical reaction predominantly gives a single product from the TS, and the rate of product formation is governed by the TS according to the kinetic theory. 12−15 A unique reaction that produces two degenerate [2 + 4]-and [4 + 2]-cycloadducts through a single bispericyclic TS was unexpectedly noted by Caramella et al 16,17 Its peculiar nature has subsequently triggered the attention of the scientific community to probe this reaction in various other scaffolds.…”