title: Understanding bond formation in polar one-step reactions. Topological analyses of the reaction between nitrones and lithium ynolates.
abstract: The mechanism of the reaction between nitrones and lithium ynolates has been studied using DFT methods at the M06-2X/cc-pVTZ/PCM=THF level. After the formation of a starting complex an without energy barrier, in which the lithium atom is coordinated to both nitrone and ynolate, the reaction takes place in one single kinetic step through a single transition structure. However, the formation of C-C and C-O bonds takes place sequentially through a typical two-stage, one-step process. A combined study of noncovalent interactions (NCIs) and electron localization function (ELFs) of selected points along the intrinsic reaction coordinate (IRC) of the reaction confirmed that, in the transition structure, only the C-C bond is being formed to some extent, whereas an electrostatic interaction is present between carbon and oxygen atoms previous to the formation of the C-O bond. Indeed, the formation of the second C-O bond only begins when the first C-C bond is completely formed without formation of any intermediate. Once the C-C bond is formed and before the C-O bond formation starts the RMS gradient norm dips, approaching but not reaching 0, giving rise to a hidden intermediate.
authors: †Laboratorio de Sı́ntesis Asimétrica, Departamento de Sı́ntesis y Estructura de Biomoléculas, Instituto de Sı́ntesis Quı́mica y Catálisis Homogénea (ISQCH), Universidad de Zaragoza, CSIC, Campus San Francisco, E-50009 Zaragoza, Aragón, Spain.
authors: David
authors: D
authors: Roca-López
authors: ‡Departamento de Quı́mica Fı́sica and Insitituto de Biocomputación y Fı́sica de Sistemas Complejos (BIFI), Universidad de Zaragoza, Campus San Francisco, E-50009 Zaragoza, Aragón, Spain.
authors: Victor
authors: V
authors: Polo
authors: †Laboratorio de Sı́ntesis Asimétrica, Departamento de Sı́ntesis y Estructura de Biomoléculas, Instituto de Sı́ntesis Quı́mica y Catálisis Homogénea (ISQCH), Universidad de Zaragoza, CSIC, Campus San Francisco, E-50009 Zaragoza, Aragón, Spain.
authors: Tomás
authors: T
authors: Tejero
authors: †Laboratorio de Sı́ntesis Asimétrica, Departamento de Sı́ntesis y Estructura de Biomoléculas, Instituto de Sı́ntesis Quı́mica y Catálisis Homogénea (ISQCH), Universidad de Zaragoza, CSIC, Campus San Francisco, E-50009 Zaragoza, Aragón, Spain.
authors: Pedro
authors: P
authors: Merino