Pericyclic versus Pseudopericyclic Reactions. What the Laplacian of the Charge Density, ∇<sup>2</sup>ρ(<i>r</i>), Has To Say about It? The Case of Cycloaddition Reactions

Calvo-Losada, Saturnino; Quirante, J.J.

doi:10.1021/jp711565g

Cited by 24 publications

(32 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…26 If ∇ 2 ρ (r) < 0 then there is a shared interaction associated with the covalent and polar bonds and when ∇ 2 ρ (r) > 0, there is a closed shell interaction associated with ionic, hydrogen bonds and van der Waals complexes. Table 6 presents the BCP properties of every bond in the all reactions 1-6 under study.…”

Section: Bond Critical Property Analysismentioning

confidence: 99%

See 1 more Smart Citation

Fluorine effect on pericyclic and pseudopericyclic processes: Evidences and ab initio theory

2009

View full text Add to dashboard Cite

Electrocyclic ring opening (ERO) reactions of 2-pyrone, 2-pyranol and pyran and their fluoro compounds (1-6) have been studied at MP2/6-31G(d) level with special emphasis on the influence of fluorine on these pericyclic/pseudopericyclic processes. Calculations clearly predict that substitution of fluorine at C6 favour the reaction both kinetically and thermodynamically. Magnetic susceptibility anisotropy (Δχ aniso ), NICS(0), NBO and bond critical property (BCP) analyses clearly illustrate the following; 2-pyrone (1) and 6-fluoro-2-pyrone (2) reactions are pseudopericyclic; 6-fluoro-2-pyranol (reaction 4) corresponds to a borderline case; 2-pyranol (3) and pyran (5) and 6-fluoro pyran (6) reactions are clearly pericyclic in character. Correspondingly pseudeopericyclic reactions show up orbital disconnections and fluorine delays the occurrence of orbital disconnections on the reaction trajectory.

show abstract

Section: Bond Critical Property Analysismentioning

confidence: 99%

“…Lopez and de Lera et al 20 showed that pseudopericyclic reactions do not show a maximum in ellipticity of the forming bond along the reaction coordinate. Recently ELF, BCP [21][22][23][24][25][26] analyses have also been used to differentiate pericyclic reactions from pseudopericyclic reactions.…”

Section: Introductionmentioning

confidence: 99%

Fluorine effect on pericyclic and pseudopericyclic processes: Evidences and ab initio theory

2009

View full text Add to dashboard Cite

show abstract

“…However, the formation of the meta enyne as the major product at short reaction times in dichlorometane observed with highly substituted systems and why the cycloadduct became the major product when the reaction was left for longer could not be completely rationalized. The analysis based on QTAIM along the reaction paths connecting the stationary points has been successfully applied to rationalize the mechanism of chemical reactions, such as the DA reactions of unsaturated organoboron dienophiles, 25 the dimerization of cyclopentadiene, 26 the Cope rearrangement of 1,5hexadiene, 27 pericyclic and pseudopericyclic reactions, [28][29][30][31][32][33][34] among others. This study indicated that in the initial stage of the reaction the σ-overlap between the 2p atomic orbitals is more stabilizing for the C-B secondary interaction than for the C-C counterpart, favoring the [4 + 3] pathway.…”

Section: Introductionmentioning

confidence: 99%

Competing mechanisms for the reaction of dichloropropynylborane with 2-tert-butylbutadiene. Diels–Alder reaction versus alkynylboration

Vallejos

Pellegrinet

2015

RSC Adv.

View full text Add to dashboard Cite

Density functional theory and the quantum theory of atoms in molecules approach were used to study two competing process: the Diels-Alder reaction (DA) and the 1,4-alkynylboration (AB) between dichloropropynylborane (1) and 2-tertbutylbutadiene (2) in dichloromethane. We analyzed several reaction pathways related with such reactions for both orientations (meta and para). The stepwise mechanisms for the two competitive reactions share the first step that leads to an intermediate zwitterionic structure. The second step is more favorable for the reaction occurring via TSC-m that leads to the meta enyne product 5, which is the kinetic product. The formation of the meta DA product cannot be explained through a direct cycloaddition, due to the higher activation free energy of the associated transition structure (TSB-m). An alternative transition structure with [4 + 3] character (TSD-m) that connects the meta enyne 5 with the meta cycloadduct 3 was found. We propose that at longer reaction times, 5 rearranges to the thermodynamic product 3 via TSD-m passing by a six-membered ring structure and a seven-membered ring structure. The topological analysis of the charge density along the selected reaction coordinates provided some understanding on the intriguing competitive reactions. ConclusionsThe reaction of dichloropropynylborane (1) with 2-tertbutylbutadiene (2) has been studied using density functional theory and the QTAIM approach in DCM in order to rationalize the mechanisms associated with the competing DA and AB reactions, and the origin of the experimental regioselectivity.

show abstract

“…Recently, a study on the nature of Cl · · · N interactions in complexes formed between substituted ammonium [NH n (X 3‐n ) (with n = 0, 1, 2, 3 and X = –CH 3 , –F)] as Lewis bases and F–Cl molecule as Lewis acid showed that these complexes result from the interaction between a local maximum with a minimum (or saddle) in the Laplacian distribution . Finally, also pericyclic and pseudopericyclic reactions were studied using the Laplacian of the electron density …”

Section: Introductionmentioning

confidence: 99%

“…[18] Finally, also pericyclic and pseudopericyclic reactions were studied using the Laplacian of the electron density. [19] Similarly, the Atoms in Molecules (AIM) theory is applied in this work to study carbocationic transition states involved in two different reaction mechanisms proposed in the olefin reactions over Brønsted-acid site of zeolite catalyst. This allows us to increase our understanding of stereoelectronic aspects of these chemical reactions.…”

Section: Introductionmentioning

confidence: 99%

Laplacian of the electron density: a hole–lump interaction as a tool to study stereoelectronic control of chemical reactions

Zalazar

Peruchena

2013

J of Physical Organic Chem

View full text Add to dashboard Cite

a In this work, we applied the theory of Atoms in Molecules to the study of carbocationic transition states involved in two different reaction mechanisms, using the proposed mechanism of ethylene dimerization over Brønsted-acid site of zeolite catalyst as a study case. We report the main results of the analysis of the Laplacian of electron density distribution and Bader's atomic charges to increase our understanding of stereoelectronic aspects of these chemical reactions. At B3LYP/6-31++G(d,p)//B3LYP/6-3G(d,p) level, our results show that the envelopes of Laplacian distribution provide valuable information about the relative orientation of the species involved in the reaction, their interaction with the catalyst surface, and its stability. The stabilization and formation of these transition states depend on the availability of electrons in the environment. Such availability plays a key role to stabilize the positive charge on the carbocationic center and, thus, to stabilize the formed carbocation. The analysis of envelopes of Laplacian could be used to study different organic and inorganic chemical reactions and provide new insights to increase our understanding of these chemical reactions.

show abstract

Pericyclic versus Pseudopericyclic Reactions. What the Laplacian of the Charge Density, ∇²ρ(r), Has To Say about It? The Case of Cycloaddition Reactions

Cited by 24 publications

References 57 publications

Fluorine effect on pericyclic and pseudopericyclic processes: Evidences and ab initio theory

Fluorine effect on pericyclic and pseudopericyclic processes: Evidences and ab initio theory

Competing mechanisms for the reaction of dichloropropynylborane with 2-tert-butylbutadiene. Diels–Alder reaction versus alkynylboration

Laplacian of the electron density: a hole–lump interaction as a tool to study stereoelectronic control of chemical reactions

Contact Info

Product

Resources

About

Pericyclic versus Pseudopericyclic Reactions. What the Laplacian of the Charge Density, ∇2ρ(r), Has To Say about It? The Case of Cycloaddition Reactions

Cited by 24 publications

References 57 publications

Fluorine effect on pericyclic and pseudopericyclic processes: Evidences and ab initio theory

Fluorine effect on pericyclic and pseudopericyclic processes: Evidences and ab initio theory

Competing mechanisms for the reaction of dichloropropynylborane with 2-tert-butylbutadiene. Diels–Alder reaction versus alkynylboration

Laplacian of the electron density: a hole–lump interaction as a tool to study stereoelectronic control of chemical reactions

Contact Info

Product

Resources

About

Pericyclic versus Pseudopericyclic Reactions. What the Laplacian of the Charge Density, ∇²ρ(r), Has To Say about It? The Case of Cycloaddition Reactions