Fernandes Anthony J, Giri Rahul, Houk Kendall N, Katayev Dmitry
Department für Chemie und Biochemie, Universität Bern, Freiestrasse 3, 3012, Bern, Switzerland.
Department of Chemistry and Biochemistry, University of California, 90095, Los Angeles, California, United States.
Angew Chem Int Ed Engl. 2024 Apr 15;63(16):e202318377. doi: 10.1002/anie.202318377. Epub 2024 Feb 14.
We highlight key contributions in the field of direct radical C- H (hetero)aromatic functionalization involving fluorinated radicals. A compilation of Functional Group Transfer Reagents and their diverse activation mechanisms leading to the release of radicals are discussed. The substrate scope for each radical is analyzed and classified into three categories according to the electronic properties of the substrates. Density functional theory computational analysis provides insights into the chemical reactivity of several fluorinated radicals through their electrophilicity and nucleophilicity parameters. Theoretical analysis of their reduction potentials also highlights the remarkable correlation between electrophilicity and oxidizing ability. It is also established that highly fluorinated radicals (e.g. ⋅OCF) are capable of engaging in single-electron transfer (SET) processes rather than radical addition, which is in good agreement with experimental literature data. A reactivity scale, based on activation barrier of addition of these radicals to benzene is also elaborated using the high accuracy DLPNO-(U)CCSD(T) method.
我们重点介绍了涉及氟化自由基的直接自由基C-H（杂）芳基官能化领域的关键贡献。讨论了官能团转移试剂及其导致自由基释放的多种活化机制的汇编。根据底物的电子性质，分析了每个自由基的底物范围并将其分为三类。密度泛函理论计算分析通过亲电和亲核参数深入了解了几种氟化自由基的化学反应性。对其还原电位的理论分析也突出了亲电性与氧化能力之间的显著相关性。还确定了高度氟化的自由基（例如⋅OCF）能够参与单电子转移（SET）过程而不是自由基加成，这与实验文献数据高度一致。还使用高精度DLPNO-(U)CCSD(T)方法阐述了基于这些自由基与苯加成活化能垒的反应活性标度。
