Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University , Ithaca, New York 14853-1301, United States.
J Am Chem Soc. 2017 Oct 25;139(42):15197-15204. doi: 10.1021/jacs.7b08734. Epub 2017 Oct 16.
Sodium diisopropylamide (NaDA)-mediated metalations of arenes in tetrahydrofuran (THF)/hexane or THF/MeNEt solutions are described. A survey of >40 benzenoid- and pyridine-based arenes with a range of substituents demonstrates the efficacy and regioselectivity of metalation. Metalations of activated disubstituted arenes and selected monosubstituted arenes are rapid at -78 °C. Rate studies of 1,3-dimethoxybenzene and related methoxylated arenes show exclusively monomer-based orthometalations with two or three coordinated THF ligands. Rate studies of the isotopic exchange of benzene and monosubstituted arenes with weakly activating groups reveal analogous di- and trisolvated monomer-based metalations. Cooperative inductive, mesomeric, steric, and chelate effects are discussed.
本文描述了在四氢呋喃（THF）/正己烷或 THF/MeNEt 溶液中，二异丙基胺钠（NaDA）介导的芳基金属化反应。对 40 多种苯系和吡啶系芳基进行了广泛的研究，这些芳基具有多种取代基，证明了金属化的有效性和区域选择性。在 -78°C 下，活化的二取代芳基和选定的单取代芳基的金属化反应迅速。对 1,3-二甲氧基苯和相关甲氧基芳基的速率研究表明，只有两个或三个配位的 THF 配体的单体基邻位金属化。对具有弱活化基团的苯和单取代芳基的同位素交换的速率研究揭示了类似的二和三溶剂化单体基金属化。讨论了协同诱导、介电、空间位阻和螯合效应。
