A simple and efficient Mn-catalyzed acylation of amines is achieved using both acyl and alkoxy functions of unactivated esters with the liberation of molecular hydrogen as a sole byproduct. The present protocol provides an atom-economical and sustainable route for the synthesis of amides from esters by employing an earth-abundant manganese salt and inexpensive phosphine-free tridentate ligand.
Highly Selective Hydrogenation of C═C Bonds Catalyzed by a Rhodium Hydride
作者:Yiting Gu、Jack R. Norton、Farbod Salahi、Vladislav G. Lisnyak、Zhiyao Zhou、Scott A. Snyder
DOI:10.1021/jacs.1c04683
日期:2021.6.30
Undermildconditions (room temperature, 80 psi of H2) Cp*Rh(2-(2-pyridyl)phenyl)H catalyzes the selectivehydrogenation of the C═C bond in α,β-unsaturated carbonyl compounds, including natural product precursors with bulky substituents in the β position and substrates possessing an array of additional functionalgroups. It also catalyzes the hydrogenation of many isolated double bonds. Mechanistic
在温和条件下(室温,80 psi H 2)Cp*Rh(2-(2-吡啶基)苯基)H催化α,β-不饱和羰基化合物(包括天然产物前体)中C=C键的选择性氢化在 β 位具有庞大的取代基,并且底物具有一系列额外的官能团。它还催化许多分离的双键的氢化。机理研究表明,不涉及自由基中间体,并且催化剂似乎是均相的,从而为类似氢化过程的现有方案提供了重要的互补性。
Preparation of Tertiary Amides from Carbamoyl Chlorides and Organocuprates
[reaction: see text] Reaction of carbamoyl chlorides with cyano-Gilman cuprates affords tertiary amides in good to excellent yields. The reaction is general due to the possibility of using reagents made either from organolithium or from Grignard compounds. The characterization of the main side products allowed for the suggestion of a possible mechanism.
The use of readily available hydroxamic acids as reagents for the chemoselective (ortho‐amino)arylation of amides is described. This reaction proceeds under metal‐free, mild conditions, displays a very broad scope, and constitutes a direct approach for the metal‐free attachment of aniline residues to carbonyl derivatives.
Tandem Photoredox Catalysis: Enabling Carbonylative Amidation of Aryl and Alkylhalides
作者:José A. Forni、Nenad Micic、Timothy U. Connell、Geethika Weragoda、Anastasios Polyzos
DOI:10.1002/anie.202006720
日期:2020.10.12
visible‐light‐mediated carbonylative amidation of aryl, heteroaryl, and alkyl halides. A tandem catalytic cycle of [Ir(ppy)2(dtb‐bpy)]+ generates a potent iridium photoreductant through a second catalytic cycle in the presence of DIPEA, which productively engages aryl bromides, iodides, and even chlorides as well as primary, secondary, and tertiary alkyl iodides. The versatile in situ generated catalyst is compatible