Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 Canada.
J Org Chem. 2022 Jan 21;87(2):1421-1433. doi: 10.1021/acs.joc.1c02725. Epub 2021 Dec 29.
Density functional theory was used to calculate C-H bond dissociation enthalpies (BDEs) at each position of a diverse collection of pyranosides and furanosides differing in relative configuration and substitution patterns. A detailed analysis of the resulting data set (186 BDEs, calculated at the M06-2X/def2-TZVP level of theory) highlights the ways in which stereoelectronic effects, conformational properties, and noncovalent interactions can influence the strengths of C-H bonds in carbohydrates. The results point toward opportunities to alter the radical reactivity of carbohydrate derivatives by variation of their stereochemical configuration or the positions and types of protective groups.
密度泛函理论被用于计算不同吡喃糖苷和呋喃糖苷的 C-H 键离解焓 (BDE) 在其各个位置的值，这些糖苷在相对构型和取代模式上存在差异。对所得数据集（186 个 BDE，在 M06-2X/def2-TZVP 理论水平上计算得出）的详细分析强调了立体电子效应、构象性质和非共价相互作用如何影响碳水化合物中 C-H 键的强度。研究结果表明，可以通过改变糖衍生物的立体化学构型或保护基团的位置和类型来改变其自由基反应性。
