title: Four-membered heterocycles with a carbon-heteroatom exocyclic double bond at the 3-position: puckering potential and thermodynamic properties.
abstract: Despite the specific importance of four-membered heterocycles with a carbon-heteroatom double bond at the 3-position in organic and medicinal chemistry, little attention has been given up to now to theoretical computational studies on these molecules. However, the overall geometry, and degree of ring puckering especially, could significantly influence the reactivity and biological properties of these four-membered ring compounds. In this paper, focus is made on the influence of different substituents on the equilibrium geometry, ring puckering potential, and thermodynamic quantities. It was found that these properties are mainly affected by the heteroatom (oxygen, nitrogen, sulfur, phosphorus) contained in the ring skeleton. Moreover, the correct description of the puckering potential with the hindered rotor treatment leads to substantial corrections on the thermodynamic properties in the harmonic oscillator approximation.
authors: Center of Molecular Modeling, Ghent University, Proeftuinstraat 86, B-9000 Ghent, Belgium.
authors: Peter
authors: P
authors: Vansteenkiste
authors: Veronique
authors: V
authors: Van Speybroeck
authors: Guido
authors: G
authors: Verniest
authors: Norbert
authors: N
authors: De Kimpe
authors: Michel
authors: M
authors: Waroquier
mesh_terms: D002244:Carbon / Q000737:chemistry*; D003503:Cyclobutanes / Q000737:chemistry; D006576:Heterocyclic Compounds, 4 or More Rings / Q000737:chemistry*; D008968:Molecular Conformation; D013816:Thermodynamics
chemical_list: D003503:Cyclobutanes; D006576:Heterocyclic Compounds, 4 or More Rings; D002244:Carbon