Conformational transformations and autooxidation of 5-bromo-2-(2-methylpropyl)-5-nitro-1,3,2-dioxaborinane

• Published in: Russian journal of organic chemistry Vol. 53; no. 6; pp. 926 - 931
• Main Authors: Valiakhmetova, O. Yu, Tyumkina, T. V., Meshcheryakova, E. S., Khalilov, L. M., Kuznetsov, V. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-06-2017; Springer Nature B.V
• Subjects: Chemistry; Chemistry and Materials Science; Diffraction; Nitropropane; NMR; Nuclear magnetic resonance; Organic Chemistry; X-ray diffraction
• ISSN: 1070-4280; 1608-3393
• DOI: 10.1134/S1070428017060185

Conformational study of 5-bromo-2-(2-methylpropyl)-5-nitro-1,3,2-dioxaborinane at the DFT PBE/3ξ level of theory revealed the only
sofa–sofa
interconversion pathway through a transition state corresponding to 2,5-
twist
conformer. The barrier to internal rotation of the axial nitro group is several times higher than that for the equatorial nitro group. According to the
1
H,
13
C, and
11
B NMR, IR, and X-ray diffraction data, the main autooxidation products of 5-bromo-2-(2-methylpropyl)-5-nitro-1,3,2-dioxaborinane are 2-bromo-2-nitropropane-1,3-diol and boric acid.