Synthesis, crystal structure, and DFT study of methyl 3-fluoro- 5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoate and (2-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl) (pyrrolidin-1-yl)methanone compounds

Methyl 3-fluoro-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzoate and (2-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)(pyrrolidin-1-yl)methanone are boric acid ester intermediates with benzene rings. In this paper, the title compounds are obtained by a three-step substitution reaction. The structures of the compounds are confirmed by FTIR, 1H and 13C NMR spectroscopy, and mass spectrometry. At the same time, single crystals of the title compounds are measured by X-ray diffraction and subjected to crystallographic and conformational analyses. The molecular structures are further calculated using density functional theory (DFT) and, which were compared with the X-ray diffraction value. The results of the conformational analysis indicate that the molecular structures optimized by DFT are consistent with the crystal structures determined by single crystal X-ray diffraction. In addition, the molecular electrostatic potential and frontier molecular orbitals of the title compounds are further investigated by DFT, and some physicochemical properties of the compounds are revealed.