Tautomerism and Regioselectivity of the Protonation of 2-Pyrrolidone. Stereoselectivity of Complexation between Palladium(II), Chloride Ion, and 2-Pyrrolidone

Pankratov, A. N.; Бородулин, В. Б.; Chaplygina, O. A.

doi:10.1007/s11173-005-0125-z

Cited by 7 publications

(4 citation statements)

References 17 publications

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“…IR and Raman spectroscopic data along with the results of dielectric measurements in different solvents testify the existence of monomer-dimer equilibrium. [15][16][17] The structure of 2-pyrrolidone monomers has been explored extensively by various experimental 18 and theoretical [18][19][20][21][22][23][24] methods.…”

Section: Introductionmentioning

confidence: 99%

DFT Study of the Monomers and Dimers of 2-Pyrrolidone: Equilibrium Structures, Vibrational, Orbital, Topological, and NBO Analysis of Hydrogen-Bonded Interactions

et al. 2005

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A computational study of the monomers and hydrogen-bonded dimers of 2-pyrrolidone was executed at different DFT levels and basis sets. The above dimeric complexes were treated theoretically to elucidate the nature of the intermolecular hydrogen bonds, geometry, thermodynamic parameters, interaction energies, and charge transfer. The processes of dimer formation from monomers and concerted reactions of double proton transfer were considered. The evolution of geometry, vibrational frequencies, charge distribution, and AIM properties in going from monomers to dimers was systematically followed. The solvent effects upon dimer formation were investigated in terms of the self-consistent reaction field (SCRF Onsager model). For the monomers and three dimers, vibrational frequencies were calculated and the changes in frequencies of the vibrations most sensitive to complexation were discussed. The orbital interactions were shown to lengthen the X-H (X = N, O) bond and lower its vibrational frequency (a red shift). To better understand the nature of the corresponding intermolecular interactions, we performed natural bond orbital (NBO) analysis. Topological analysis of electron density at bond critical points (BCP) was executed for complex molecules using the Bader's atoms in molecules (AIM) theory. The interaction energies were calculated, and the basis set superposition errors (BSSE) were estimated systematically. Satisfactory correlations between the structural parameters, interaction energies, and electron density characteristics at BCP were found.

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Section: Introductionmentioning

confidence: 99%

DFT Study of the Monomers and Dimers of 2-Pyrrolidone: Equilibrium Structures, Vibrational, Orbital, Topological, and NBO Analysis of Hydrogen-Bonded Interactions

et al. 2005

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“…When dissolved in water, solvation stabilizes the lactim tautomer preferentially due to more favorable hydrogen bonding. However, even in water, the lactam tautomer of pyrrolidone is predicted to be 18.9 kJ/mol enthalpically more stable than the lactim (32). Assuming a typical entropy of tautomerism, this enthalpy corresponds to an equilibrium constant at 25 °C of only 5 × 10 −4 for the formation of the lactim, 1-pyrrolin-2-ol.…”

Section: Lactam-lactim Tautomerism Of Pyrrolidones and Caprolactamsmentioning

confidence: 96%

Introduction to Pyrrolidone and Caprolactam Chemistry

Chenault

2021

Handbook of Pyrrolidone and Caprolactam Based Materials

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Pyrrolidones and caprolactams are important structural components of solvents, surfactants, polymers, natural products, and pharmaceuticals. This chapter provides an introduction to the structure, conformation, physical properties and reactivity of pyrrolidones and caprolactams. It begins with an overview of the nomenclature of lactams since there are several systems of nomenclature in practice, plus common names and various syncretisms. Next, the structures of pyrrolidone and caprolactam are discussed, starting with the X-ray crystal structures of pyrrolidone, N-methylpyrrolidone (NMP) and caprolactam. The conformational flexibility and ring strain of the two ring systems are also covered.Physical properties, such as dipole moments, the enthalpies of formation, vaporization and fusion, boiling points and melting points, are described. An attempt is made to put the properties of pyrrolidones and caprolactams into context with those of other lactams, amides and even lactones and cyclic ketones. Brønsted and Lewis basicity, acidity, hydrogen bonding and solubility are covered.Finally, a brief description of the basic reactivity of pyrrolidones and caprolactams is given. Topics covered are N-, O-, and α-C-alkylation, hydrolysis, reactions with organometallics, reduction, oxidation, and ring-opening polymerization. The intent is to give a concise physical organic perspective on reactivity (and stability) more than an extended treatise on synthetic elaborations. Definition and Nomenclature of LactamsLactams are cyclic amides in which both the carbonyl carbon and nitrogen atom of the amide group are part of a ring. The name, lactam, is a portmanteau of lactone (cyclic ester) and amide.Nomenclature of lactams follows a variety of conventions (Figure 1 and Table 1). The International Union of Pure and Applied Chemistry (IUPAC) recommends naming lactams as heterocyclic pseudoketones (IUPAC method 1) or by substituting lactam for the

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“…The proton transfer effect of 2-PY would be more pronounced if it could exist in an enol form. 2-PY is known to exist as a keto-enol tautomer through the migration of a labile NÀH hydrogen atom from the ring nitrogen or oxygen atom as shown in Scheme 1, however, the equilibrium constant toward the enol form is calculated to be as low as 1.45 3 10 À7 at 300 K. [16] Nonetheless, the equilibrium constant is expected to be greatly increased if the enol form of 2-PY is stabilized by a carbonation species like I or II.…”

Section: Mechanistic Considerationmentioning

confidence: 99%

Efficient Non‐Catalytic Carboxylation of Diamines to Cyclic Ureas Using 2‐Pyrrolidone as a Solvent and a Promoter

Hwang

Han

et al. 2018

Adv Synth Catal

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Carboxylation reactions of diamines were found to proceed rapidly and non-catalytically, producing corresponding cyclic ureas in excellent yields and selectivities when 2-pyrrolidone (2-PY) was used as a solvent. A similar promoting effect with 2-PY was also observed for the carboxylation of monoamines by carbon dioxide (CO 2 ). Most notably, the carboxylation reactions of mono-and diamines conducted in 2-PY afforded 2-4 times higher yields of corresponding dialkyl ureas and cyclic ureas compared with those in Nmethyl-2-pyrrolidone (NMP). Such a dramatic promoting effect using 2-PY is believed to be associated with the multiple hydrogen bonding interactions between 2-PY and the CO 2 -containing species of amines. Due to such favorable interactions, carboxylation reactions seem to be more facilitated in 2-PY than in NMP.

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Tautomerism and Regioselectivity of the Protonation of 2-Pyrrolidone. Stereoselectivity of Complexation between Palladium(II), Chloride Ion, and 2-Pyrrolidone

Cited by 7 publications

References 17 publications

DFT Study of the Monomers and Dimers of 2-Pyrrolidone: Equilibrium Structures, Vibrational, Orbital, Topological, and NBO Analysis of Hydrogen-Bonded Interactions

DFT Study of the Monomers and Dimers of 2-Pyrrolidone: Equilibrium Structures, Vibrational, Orbital, Topological, and NBO Analysis of Hydrogen-Bonded Interactions

Introduction to Pyrrolidone and Caprolactam Chemistry

Efficient Non‐Catalytic Carboxylation of Diamines to Cyclic Ureas Using 2‐Pyrrolidone as a Solvent and a Promoter

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