Thermal electrorocyclic ring-opening of cyclobutenes: substituents with complementary conrotatory preferences induce high stereoselectivity

Hayes, Roy; Ingham, Stephen; Saengchantara, S. T.; Wallace, Timothy W.

doi:10.1016/0040-4039(91)80660-x

Cited by 27 publications

(19 citation statements)

References 11 publications

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“…This hypothesis is consistent with a diminution in the inward rotation preference when the π‐acceptor character of the substituent decreases [COCl > CO 2 H ≈ CO 2 (2‐Naph) > CO 2 Me] 1d,23. Another withdrawing substituent, the amide group, gave good selectivity 24…”

Section: Introductionsupporting

confidence: 61%

Oxoanion Binding by Guanidiniocarbonylpyrrole Cations in Water: A Combined DFT and MD Investigation

Moiani

Cavallotti

Famulari

et al. 2008

Chemistry A European J

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Structures and properties of nonbonding interactions involving guanidinium-functionalized hosts and carboxylate substrates were investigated by a combination of ab initio and molecular dynamics approaches. The systems under study are on one hand intended to be a model of the arginine-anion bond, so often observed in proteins and nucleic acids, and on the other to provide an opportunity to investigate the influence of molecular structure on the formation of supramolecular complexes in detail. Use of DFT calculations, including extended basis sets and implicit water treatment, allowed us to determine minimum-energy structures and binding enthalpies that compared well with experimental data. Intermolecular forces were found to be mostly due to electrostatic interactions through three hydrogen bonds, one of which is bifurcate, and are sufficiently strong to induce a conformational change in the ligand consisting of a rotation of about 180 degrees around the guanidiniocarbonylpyrrole axis. Free binding energies of the complexes were evaluated through MD simulations performed in the presence of explicit water molecules by use of the molecular mechanics Poisson-Boltzmann solvent accessible surface area (MM-PBSA) and linear interaction energy (LIE) approaches. LIE energies were in quantitative agreement with experimental data. A detailed analysis of the MD simulations revealed that the complexes cannot be described in terms of a single binding structure, but that they are characterized by a significant internal mobility responsible for several low-energy metastable structures.

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Section: Introductionsupporting

confidence: 61%

Oxoanion Binding by Guanidiniocarbonylpyrrole Cations in Water: A Combined DFT and MD Investigation

Moiani

Cavallotti

Famulari

et al. 2008

Chemistry A European J

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“…We calculated a temperature of >2000 K after photoexcitation in the central part of the stiff-stilbene moiety in the macrocycle containing cyclobutene . It is reasonable to assume that this energy is dissipated rapidly in the macrocycle and is the key factor for the acceleration of the bond rupture in cyclobutene, although this view has been discussed controversially. , The scissile bond in cyclobutene is thermally labile by nature, and depending on the substitution pattern, only moderate heating is needed for rupture. − The significant influence of thermal oscillations in this reaction has also been acknowledged in previous literature . We speculate that the rapid heating upon absorption of a photon is a general working principle of photoswitches and a determining factor in the initiation of various processes like structural changes in proteins − and DNA. , …”

Section: Applications Of Quantum Mechanochemistrymentioning

confidence: 99%

Advances in Quantum Mechanochemistry: Electronic Structure Methods and Force Analysis

2016

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In quantum mechanochemistry, quantum chemical methods are used to describe molecules under the influence of an external force. The calculation of geometries, energies, transition states, reaction rates, and spectroscopic properties of molecules on the force-modified potential energy surfaces is the key to gain an in-depth understanding of mechanochemical processes at the molecular level. In this review, we present recent advances in the field of quantum mechanochemistry and introduce the quantum chemical methods used to calculate the properties of molecules under an external force. We place special emphasis on quantum chemical force analysis tools, which can be used to identify the mechanochemically relevant degrees of freedom in a deformed molecule, and spotlight selected applications of quantum mechanochemical methods to point out their synergistic relationship with experiments.

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“…The effect of substituents on the direction of conrotation in electrocyclic reactions was first explained by Kirmse, Rondan, and Houk in 1985 for the cyclobutene ring opening 1a. The theory has been elaborated and verified experimentally for a number of reactions of cyclobutenes . Since then the theory of stereoelectronic control of the direction of twisting of the breaking bond (torquoselectivity) has been extended to the pentadienyl cation cyclization, the hexatriene−cyclohexadiene interconversion,3a the octatetraene−cyclooctatriene interconversion,3b the electrocyclic ring openings of azetines, oxetenes, and thietenes, the ring opening of cyclopropenes, and the electrocyclic openings of aziridines and oxiranes, as well as cyclopentenyl anions .…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Theoretical Predictions of Substituent Effects on the Thermal Electrocyclic Ring Openings of Cyclobutenones

et al. 1996

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Thermal electrorocyclic ring-opening of cyclobutenes: substituents with complementary conrotatory preferences induce high stereoselectivity

Cited by 27 publications

References 11 publications

Oxoanion Binding by Guanidiniocarbonylpyrrole Cations in Water: A Combined DFT and MD Investigation

Oxoanion Binding by Guanidiniocarbonylpyrrole Cations in Water: A Combined DFT and MD Investigation

Advances in Quantum Mechanochemistry: Electronic Structure Methods and Force Analysis

Theoretical Predictions of Substituent Effects on the Thermal Electrocyclic Ring Openings of Cyclobutenones

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