Center for Computational Molecular Science and Technology, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA.
Phys Chem Chem Phys. 2018 Jul 11;20(27):18241-18251. doi: 10.1039/c8cp02029a.
This work seeks to apply symmetry-adapted perturbation theory (SAPT) to the recent study of Hoveyda and co-workers [K. A. Lee et al., Nat. Chem. 2016, 8, 768] where an allyl addition to a ketone became enantioselective when the ketone was fluorinated. Through the application of atomic SAPT (A-SAPT) and functional-group SAPT (F-SAPT), the non-covalent interactions between specific atoms and functional groups in the transition states associated with the fluoroketone reactions can be quantified. Our A-SAPT analysis confirms that a HF contact thought to enhance stereoselectivity shows a strong preference for one of the transition states leading to the experimentally observed product enantiomer. Other key atom-atom contacts invoked to rationalize relative transition state energies are also found to behave as expected based on chemical intuition and contact distances. On the other hand, hypothesized steric clashes between substrate phenyl or ortho-methyl phenyl groups and the catalyst are not supported by F-SAPT computations, and indeed, these are actually favorable π-π interactions.
这项工作旨在将对称自适应微扰理论（SAPT）应用于 Hoveyda 及其同事最近的研究[K. A. Lee 等人，Nat. Chem. 2016, 8, 768]，其中当酮被氟化时，烯丙基加成到酮上成为对映选择性的。通过原子 SAPT（A-SAPT）和官能团 SAPT（F-SAPT）的应用，可以量化与氟代酮反应相关的过渡态中特定原子和官能团之间的非共价相互作用。我们的 A-SAPT 分析证实，据认为增强立体选择性的 HF 接触强烈倾向于导致实验观察到的产物对映体的一个过渡态。其他被认为可以合理说明相对过渡态能量的关键原子-原子接触也被发现符合化学直觉和接触距离的预期。另一方面，F-SAPT 计算不支持底物苯基或邻甲基苯基与催化剂之间假设的空间位阻冲突，实际上，这些实际上是有利的π-π相互作用。
