- Ruthenium-Catalyzed Dehydrogenation Through an Intermolecular Hydrogen Atom Transfer Mechanism
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The direct dehydrogenation of alkanes is among the most efficient ways to access valuable alkene products. Although several catalysts have been designed to promote this transformation, they have unfortunately found limited applications in fine chemical synthesis. Here, we report a conceptually novel strategy for the catalytic, intermolecular dehydrogenation of alkanes using a ruthenium catalyst. The combination of a redox-active ligand and a sterically hindered aryl radical intermediate has unleashed this novel strategy. Importantly, mechanistic investigations have been performed to provide a conceptual framework for the further development of this new catalytic dehydrogenation system.
- Huang, Lin,Bismuto, Alessandro,Rath, Simon A.,Trapp, Nils,Morandi, Bill
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supporting information
p. 7290 - 7296
(2021/03/01)
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- Catalyst-Free, Metal-Free, and Chemoselective Transamidation of Activated Secondary Amides
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A simple protocol, which is catalyst-free, metal-free, and chemoselective, for transamidation of activated secondary amides in ethanol as solvent under mild conditions is reported. A wide range of amines, amino acids, amino alcohols, and the substituents, which are problematic in catalyzed transamidation, are tolerated in this methodology. The transamidation reaction was successfully extended to water as the medium as well. The present methodology appears to be better than the other catalyzed transamidations reported recently.
- Ramkumar, Rajagopal,Chandrasekaran, Srinivasan
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p. 921 - 932
(2019/02/10)
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- The aminocarbonylation of 1,2-diiodoarenes with primary and secondary amines catalyzed by palladium complexes with imidazole ligands
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The efficient carbonylative cyclization of 1,2-diiodobenzene with different primary and secondary amines was performed using a palladium complex with an imidazole ligand, PdCl2(BIM)2, as a catalyst. In reactions performed at 1 atm of CO with primary amines, phthalimides were obtained as the only products with yields of up to 100% in 4 h. An even shorter time, 1 h, was sufficient to obtain the same products employing methyl-2-iodobenzoate as a substrate instead of 1,2-diiodobenzene. In an analogous reaction with secondary amines, 1,2-diiodobenzene was converted to three products, formed in amounts dependent on the reaction conditions. The presence of Pd NPs and soluble palladium intermediates indicated their participation in the catalytic reaction.
- Wójcik, Przemys?aw,Trzeciak, Anna M.
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- General, Mild, and Selective Method for Desaturation of Aliphatic Amines
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A novel method for desaturation of aliphatic amines into enamines as well as allylic and homoallylic amines has been developed. This general protocol operates via putative aryl hybrid Pd-radical intermediates, which combine the signature features of radic
- Chuentragool, Padon,Parasram, Marvin,Shi, Yi,Gevorgyan, Vladimir
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supporting information
p. 2465 - 2468
(2018/02/28)
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- Synthesis of tetrahydrophthalazine and phthalamide (phthalimide) derivatives via palladium-catalysed carbonylation of iodoarenes
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1,2,3,4-Tetrahydrophthalazin-1-one and 1,2,3,4-tetrahydrophthalazin-1,4- dione derivatives were synthesised in high (up to 85%) and low yields using 2-iodobenzyl bromide and 1,2-diiodobenzene as bifunctional substrates, respectively. Iodoarenes, carbon monoxide and various hydrazine derivatives as N-nucleophiles were used in a three-component palladium-catalysed cascade hydrazinocarbonylation. A similar palladium-catalysed reaction, the aminocarbonylation of 1,2-diiodobenzene, resulted mainly in the formation of two types of major products depending on the amine N-nucleophiles: the use of primary amines yielded N-substituted phthalimides in double carbonylation, while secondary amines react with one of the iodoarene functionalities affording the corresponding 2-iodobenzamides. Due to double carbon monoxide insertion at one or both iodoarene functionalities, ketocarboxamide-carboxamide or bis-ketocarboxamide derivatives could be isolated by the modification of the reaction conditions. Some mechanistic details of the ring-closure reactions and the conditions leading to side-products are also discussed.
- Marosv?lgyi-Haskó, Diána,Petz, Andrea,Takács, Attila,Kollár, László
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experimental part
p. 9122 - 9128
(2011/12/02)
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