Analyzing torquoselectivity in a series of unusual ring‐opening reactions through bond reactivity indices and the adaptive natural density partitioning method. Issue 23 (1st September 2018)

• Record Type: Journal Article
• Authors: Morales‐Bayuelo, Alejandro; Sánchez‐Márquez, Jesús; Jana, Gourhari; Chattaraj, Pratim Kumar
• Is Part Of: International journal of quantum chemistry. Volume 118:Issue 23(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-09-01
• Subjects: adaptive natural density partitioning -- bond reactivity indices -- electrophilicities -- ring‐opening reactions -- torquoselectivity; Quantum chemistry -- Periodicals; 541.28
• DOI: 10.1002/qua.25778
• Languages: English
• ISSNs: 0020-7608

Abstract

Abstract: In this study, a theoretical analysis of the torquoselectivity in a set of unusual ring‐opening reactions (R1‐R5) is presented. To describe the mechanism of the reactions, a recent methodology has been used to estimate the electrophilicities of the natural bond orbitals of the reagents and has been complemented with a second‐order perturbation theory analysis. The adaptive natural density partitioning method has also been used to verify the results and conclusions of the analysis. The concordant results of the three methodologies provide us with a better understanding of the reaction mechanism involving the torquoselectivity. We also carried out the analysis in both directions of the reaction to verify the conclusions obtained. Abstract : Torquoselectivity determines whether an inward or an outward rotation of substituents is preferred during a conrotatory or disrotatory electrocyclic reactions, which is considered to be a secondary effect to the conservation of orbital symmetry (Woodward‐Hoffmann rules). Torquoselectivity in a set of unusual electrocyclic ring opening reactions depends mainly on the delocalization of electron density over specific natural bond orbitals in the transition state presumably originating from the related steric effects.