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Updated: Sep 30, 2025
Synthesis of a Borylated Ibuprofen Derivative Through Suzuki Cross-Coupling and Alkene Boracarboxylation Reactions
Published on: November 30, 2022
Ability of Boron to Act as a Nucleophile and an Electrophile in Boryl Shift Reactions Unveiled by Electron Density
Nora Lis G Fernández1, Roxana E Medina1, Margarita M Vallejos1
1Laboratorio de Química Orgánica, Instituto de Química Básica y Aplicada del NEA (IQUIBA-NEA, UNNE-CONICET), Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Av. Libertad 5460, Corrientes 3400, Argentina.
Abstract:
The behavior of the tetracoordinate boron of N-methyliminodiacetic acid (MIDA) boronates as a nucleophile and an electrophile during the 1,2-boryl migration promoted by a Lewis acid and the 1,4-boryl migration promoted by a neighboring atom, respectively, have been investigated using density functional theory and the quantum theory of atoms in molecules. We found that when boron acts as a nucleophile, the electron density of the B-N interaction of the BMIDA moiety maintains the charge concentration over the boron atom, facilitating its transport toward the electron-deficient center. In this process, the BMIDA remains as a tetracoordinate. On the other hand, the B-N weakening generates a charge depletion region over the boron, allowing it to interact with the electron-rich center of O1, developing the boron atom, a pentacoordinate form. Then, the B-N bond breaking triggers a series of changes in the electronic structure of the boron atom. Our results explain the role of the MIDA ligand upon the remarkable susceptibility of the boron atom for switching its structural and electronic characteristics in the migration processes. In addition, the dichotomous behavior was evaluated with a different scenario, considering tricoordinate pinacol boronate as a boryl migrating group.
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