Lennox Alastair J J
School of Chemistry, University of Bristol, Cantocks Close, Bristol, Avon, BS8 1TS, UK.
Angew Chem Int Ed Engl. 2018 Nov 5;57(45):14686-14688. doi: 10.1002/anie.201809606. Epub 2018 Oct 15.
Meisenheimer's missing! Anionic σ-complexes, best known as Meisenheimer complexes, have long been assumed to be intermediates in S Ar reactions. New evidence now suggests that these intermediates may only be formed in select cases and that a concerted pathway is more common. These claims are supported by C/ C kinetic isotopes effects, determined using a new method based on F NMR, and DFT calculations.
迈森海默中间体不见了！阴离子σ-络合物，最为人所知的是迈森海默络合物，长期以来一直被认为是芳香亲核取代反应中的中间体。现在新的证据表明，这些中间体可能只在特定情况下形成，且协同反应途径更为常见。这些说法得到了利用基于氟核磁共振的新方法测定的碳/碳动力学同位素效应以及密度泛函理论计算的支持。
