Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35043, Marburg, Germany.
Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095-1569, USA.
Angew Chem Int Ed Engl. 2020 Nov 23;59(48):21706-21710. doi: 10.1002/anie.202009335. Epub 2020 Sep 24.
This study demonstrates for the first time that easily accessible transition-metal acylnitrenoids can be used for controlled direct C(sp )-H oxygenations. Specifically, a ruthenium catalyst activates N-benzoyloxycarbamates as nitrene precursors towards regioselective intramolecular C-H oxygenations to provide cyclic carbonates, hydroxylated carbamates, or 1,2-diols. The method can be applied to the chemoselective C-H oxygenation of benzylic, allylic, and propargylic C(sp )-H bonds. The reaction can be performed in an enantioselective fashion and switched in a catalyst-controlled fashion between C-H oxygenation and C-H amination. This work provides a new reaction mode for the regiocontrolled and stereocontrolled conversion of C(sp )-H into C(sp )-O bonds.
这项研究首次证明，易于获得的过渡金属酰基氮烯可以用于可控的直接 C(sp )-H 氧化。具体来说，钌催化剂将 N-苯甲酰氧羰基作为氮烯前体激活，实现区域选择性的分子内 C-H 氧化，得到环状碳酸酯、羟基化的氨基甲酸酯或 1,2-二醇。该方法可用于选择性 C-H 氧化苄基、烯丙基和炔丙基 C(sp )-H 键。该反应可以以对映选择性的方式进行，并可以在催化剂控制的方式下在 C-H 氧化和 C-H 胺化之间切换。这项工作为区域和立体控制地将 C(sp )-H 转化为 C(sp )-O 键提供了一种新的反应模式。
