Laboratory of Synthesis and Natural Products (LSPN), Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH5304, CH-1015 Lausanne, Switzerland.
School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P. R. China.
J Am Chem Soc. 2022 Aug 10;144(31):14047-14052. doi: 10.1021/jacs.2c06578. Epub 2022 Aug 2.
Directly editing an all-carbon quaternary carbon itself of nonstrained acyclic molecules remains underexploited despite the recent advances in the fields of both C-H and C-C bond activation. Herein, we report a palladium-catalyzed migrative carbofluorination of saturated amides enabled by the activation of both the C(sp)-H and the C-Cσ bonds. In this transformation, the α-quaternary carbon of Weinreb amides is converted to α-tertiary fluoride with concurrent migration of an aryl or an amido group from the α- to β-carbon. DFT calculations indicate that the dyotropic rearrangement proceeds through an unusual -selective [2.1.0] bicyclic transition state. The reaction, compatible with a broad range of functional groups, is stereospecific and is applicable to the synthesis of enantioenriched products.
尽管在 C-H 和 C-C 键活化领域取得了最新进展,但直接编辑非环状分子的全碳季碳本身仍然未得到充分利用。在此,我们报告了钯催化的饱和酰胺的迁移氟化反应,该反应通过 C(sp)-H 和 C-Cσ 键的活化来实现。在这种转化中,Weinreb 酰胺的α-季碳与芳基或酰胺基从α-到β-碳的同时迁移,被转化为α-三氟甲基。DFT 计算表明,双自由基重排通过不寻常的 -选择性 [2.1.0] 双环过渡态进行。该反应与广泛的官能团兼容,具有立体特异性,适用于手性富集产物的合成。