title: Between a reactant rock and a solvent hard place--molecular corrals guide aromatic substitutions.
abstract: A novel reaction mechanism is presented for an ortho-magnesium carboxylate driven aromatic nucleophilic substitution in naphthoic acids, supported by high-level density functional theory. Results show that the rate-determining aspects involve an R-group transfer from a Grignard reagent Mg-atom to the C1-atom on a naphthalene ring. This transfer is moderated by a molecular corral comprised of two solvent THF molecules and the naphthoic acid, which collectively marshal the R-group into position. The CAM-B3LYP method was employed together with the all-electron DZVP basis set. Solvent was treated using an implicit dielectric continuum (PCM method) and IDSCRF atomic-radii. Further evolved solvent models were also investigated, consisting of explicit solvating particles forming a primary solvation layer framing the reaction center. Reaction barriers obtained are in close agreement with experimental trends, with R-group substituent-identity tempering repulsion with the molecular corral, in-turn modulating the free-energy barriers. Partitioning of the dynamic bases of entropy contribution to free-energy was central to the successful experimental-theoretical synergy.
authors.affiliation: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China. dcfang@bnu.edu.cn.
authors.forename: Yan-Mei
authors.initials: YM
authors.lastname: Chen
authors.forename: Gregory Adam
authors.initials: GA
authors.lastname: Chass
authors.forename: De-Cai
authors.initials: DC
authors.lastname: Fang