Rhodium‐Catalyzed Electrooxidative C−H Olefination of Benzamides
作者:Yan Zhang、Julia Struwe、Lutz Ackermann
DOI:10.1002/anie.202005257
日期:2020.8.24
Metal‐catalyzed chelation‐assisted C−H olefinations have emerged as powerful tools for the construction of functionalized alkenes. Herein, we describe the rhoda‐electrocatalyzedC−H activation/alkenylation of arenes. The olefinations of challenging electron‐poor benzamides were thus accomplished in a fully dehydrogenative fashion under electrochemical conditions, avoiding stoichiometric chemical oxidants
金属催化螯合辅助的 C-H 烯化已成为构建功能化烯烃的有力工具。在此,我们描述了 rhoda 电催化芳烃的 C-H 活化/烯基化。因此,具有挑战性的贫电子苯甲酰胺的烯烃化在电化学条件下以完全脱氢的方式完成,避免了化学计量的化学氧化剂,并且 H 2作为唯一的副产物。这种通用的烯基化反应还具有广泛的底物范围和使用电力作为绿色氧化剂。
Co(III)-Catalyzed [4+1] Annulation of Amides with Allenes via C−H Activation
Co(III)‐catalyzed [4+1] annulation of amides with allenes to synthesize isoindolone and 1,5‐dihydro‐pyrrol‐2‐one derivatives is reported. A wide range of aromatic and vinylic amides react with allenes to give the corresponding annulation products in good to excellent yields. The mechanistic studies strongly support that the catalytic reaction proceeds through an amide‐directed C−Hactivation, followed
Ruthenium-Catalyzed Oxidative Annulation by Cleavage of CH/NH Bonds
作者:Lutz Ackermann、Alexander V. Lygin、Nora Hofmann
DOI:10.1002/anie.201101943
日期:2011.7.4
Bond activation in action: Unprecedented ruthenium‐catalyzed oxidative annulations of alkynes through cleavage of CH bonds set the stage for an efficient 1(2H)‐isoquinolone synthesis with ample scope (see scheme; tAm=tert‐amyl). Mechanisticstudies provided strong evidence for a rate‐limiting CH bond metalation through carboxylate assistance.
A simple and direct C–H trifluoroethylation of aromatic amides has been developed. The protocol is applicable to a variety of aromatic amides, including ones derived from amino acids. The developed method can be used for further modifications of peptides. Preliminary mechanistic studies have been done by isolating the reaction intermediate.
Iridium-catalyzed, ligand-controlled directed alkynylation and alkenylation of arenes with terminal alkynes
作者:Xin Sun、Wei Zhao、Bi-Jie Li
DOI:10.1039/c9cc08735d
日期:——
choice of a suitable ligand, a C-H alkynylation or alkenylation product could be obtained selectively. The directed C-H alkynylation proceeded without the need for an external oxidant, while the directed C-H alkenylation likely involves an unusual vinylidene mechanism. This divergent reactivity provides access to both alkynylation and alkenylation products from the same set of starting materials.