Theoretical investigation of the abnormal Reimer-Tiemann reaction

Castillo, Raquel; Moliner, Vicent; Andrés, Juán; Oliva, Mónica; Böhm, Stanislav

doi:10.1002/(sici)1099-1395(199808/09)11:8/9<670::aid-poc56>3.0.co;2-u

Cited by 3 publications

(1 citation statement)

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“…In practice, if the system is described by quantum mechanics, the applicability of the discrete models, a supermolecule approach, is restricted to a selected number of configurations of a solute sorrounded by a few solvent molecules. 4,5 However, it does not enable the characterization of long-range bulk solvent forces. Moreover, the number of solvent molecules required to properly represent the medium for a given solute would be so large that performing a quantum chemical calculation in such a system becomes prohibitively expensive.…”

Section: Introductionmentioning

confidence: 99%

Quantum Mechanical/Molecular Mechanical Study on the Favorskii Rearrangement in Aqueous Media

2001

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In this paper, hybrid quantum mechanical/molecular mechanical (QM/MM) calculations including 500 water molecules mold solvent effects on the molecular mechanisms of the R-chlorocyclobutanone and R-chlorocyclohexanone transpositions to yield cyclopropane and cyclopentane carboxylic acids, respectively, as a model of the Favorskii rearrangement. The two accepted molecular mechanisms, the semibenzilic acid and the cyclopropanone transpositions, as well as the competition between both reaction pathways and the ring size effects are addressed in this investigation. Stationary pointssreactants, products, transition structures, and intermediary species along both reaction pathwaysshave been located and characterized, involving a fully flexible active-site region, by means of GRACE and CHARMM software. The transition structures have been connected with their respective reactants and products by the intrinsic reaction coordinate procedure carried out in the presence of water media, thus obtaining for the first time a realistic reaction pathway for this chemical transposition. The analysis of the results obtained by QM/MM methods shows that the semibenzilic acid mechanism is favored over the cyclopropanone mechanism for the R-chlorocyclobutanone system. However, the study of the ring size effects reveals that the cyclopropanone mechanism is the energetically preferred reactive channel for the R-chlorocyclohexanone ring, probably due to the straining effects on bicycle cyclopropanone, an intermediate that appears on the semibenzilic acid pathway. This later mechanism is described as a two-step one, while the cyclopropanone or Loftfield mechanism is for the first time described as a four-step reaction. These results provide new information on an important chemical reaction and the key factors responsible for the behavior of reactant systems embedded in aqueous media. This methodology allows evaluation of specific solute-solvent interactions as well as weighing up of the different energy contribution terms.

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Section: Introductionmentioning

confidence: 99%

Quantum Mechanical/Molecular Mechanical Study on the Favorskii Rearrangement in Aqueous Media

2001

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Reimer‐Tiemann Reaction

2010

Comprehensive Organic Name Reactions and Reagents

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The transformation of a formyl group onto the ortho ‐ or para ‐position of an activating group in an electron‐rich aromatic compound by warming with chloroform and aqueous alkali is generally known as the Reimer–Tiemann reaction. Several electron‐rich aromatic compounds have been suggested for this reaction. This reaction also possesses various drawbacks and the presence of an alcohol may alter the nature of the biphasic system. It has been found that this reaction generally favors the ortho ‐formylated product because of the electrostatic effect. This reaction has been improved by use of a slightly hydrated solid‐liquid medium. This reaction has been applied for the formylation of electron‐rich aromatic compounds.

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