51579-87-4Relevant academic research and scientific papers
Chemoselective formal β-functionalization of substituted aliphatic amides enabled by a facile stereoselective oxidation event
Bauer, Adriano,Maulide, Nuno
, p. 9836 - 9840 (2019)
Aliphatic C-H functionalization is a topic of current intense interest in organic synthesis. Herein, we report that a facile and stereoselective dehydrogenation event enables the functionalization of aliphatic amides at different positions in a one-pot fa
The preparation and reductive elimination behavior of trans-Pd(COPh)(CONMe2)(PMe3)2: a model intermediate in the catalytic double carbonylation of aryl halides with amines to give α-keto amides
Ozawa, Fumiyuki,Huang, Li,Yamamoto, Akio
, p. C9 - C13 (1987)
The cationic benzoylcarbonylpalladium(II) complex, trans-+BF41 (1), reacts with Me2NH under CO to give trans-Pd(COPh)(CONMe2)(PMe3)2 (3).Complex 3 is stable in neat solvent, whereas rapid decomposition of 3 to give PhCOCONMe2 takes place in the presence of Me2NH2BF4 and Me2NH under CO.
Pd-Catalyst Containing a Hemilabile P,C-Hybrid Ligand in Amino Dicarbonylation of Aryl Halides for Synthesis of α-Ketoamides
Yang, Shu-Qing,Yao, Yin-Qing,Chen, Xiao-Chao,Lu, Yong,Zhao, Xiao-Li,Liu, Ye
, p. 1032 - 1041 (2021/05/07)
The amino dicarbonylation of aryl halides affording α-ketoamides with Pd catalysts is highly dependent on the stereoelectronic properties of the involved ligands. Ionic diphosphine ligand L4 can serve as precursor of a hemilabile P,C (phosphine, carbene)-hybrid ligand to form a stable Pd(II)-complex, Pd-L4. In contrast, analogues L1-L3 with a similar 1-(thiophen-3-yl)-benzimidazolyl skeleton behave as typical (mono/di)phosphines. The catalytic system resulting from the complexation of PdCl2(MeCN)2 and L4 exhibits good catalytic performance in terms of aryl iodides conversion (81-95%) and α-ketoamide selectivity (80-91%), as well as the available recyclability in the RTIL of [Bpy]BF4. The in situ FT-IR analysis reveals that the PdCl2(MeCN)2-L4 catalytic system favors the amino dicarbonylation toward α-ketoamides according to the proposed mechanism of cycle I, which involves two independent CO-insertion steps.
Cu-Catalyzed aerobic oxidative cleavage of C(sp3)–C(sp3) bond: Synthesis of α-ketoamides
Fang, Zheng,Guo, Kai,Liu, Chengkou,Yang, Man,Zhang, Jingming
supporting information, (2020/11/02)
A novel synthesis of α-ketoamides from Cu-catalyzed aerobic oxidative C(sp3)–C(sp3) bond cleavage of hydrocinnamaldehydes has been developed. Readily available and environmentally benign oxygen is used as the oxidant. This reaction avoids the use of noble metal catalysts or specialized oxidants, and chemoselectively yields α-ketoamide. Moreover, based on various control experiments, a reasonable mechanism is proposed.
Copper-Catalyzed Oxidative Synthesis of α-Ketoamides from Aryl Methyl Ketones and N -Bromobutanimide Using N, N -Dimethylformamide as Dimethylamine Source
Li, Xiaoyan,Wei, Ying,Yan, Yongxia
, p. 393 - 397 (2020/02/27)
A novel and practical Cu(OAc) 2 -catalyzed oxidative synthesis of α-ketoamides from aryl methyl ketones and N -bromobutanimide (NBS) using N, N -dimethylformamide (DMF) as dimethylamine (HNMe 2) source and solvent has been developed under mild conditions. DMF was used as a HNMe 2 source and can be easily converted into HNMe 2 by acid hydrolysis. The mechanistic studies indicate that Cu(OAc) 2 plays a dual role in providing both catalyst and oxidant.
Copper-Mediated Synthesis of Aryl α-Keto Amides from Epoxide Derivatives
Cui, Yunjian,Dong, Yi,Liu, Fenghua,Xu, Heng
supporting information, p. 1011 - 1014 (2020/06/10)
A novel Cu II -mediated synthesis of aryl α-keto amides from epoxide derivatives is reported. This transformation was conducted by using O 2 as a green oxidant that meets the requirements of sustainable chemistry.
Amine-Mediated Bond Cleavage in Oxidized Lignin Models
Li, Hongji,Liu, Meijiang,Liu, Huifang,Luo, Nengchao,Zhang, Chaofeng,Wang, Feng
, p. 4660 - 4665 (2020/07/04)
Introducing amines/ammonia into lignin cracking will allow novel bond cleavage pathways. Herein, a method of amines/ammonia-mediated bond cleavage in oxidized lignin β-O-4 models was studied using a copper catalyst at room temperature, demonstrating the effect of the amine source on the selectivity of products. For primary and secondary aliphatic amines, lignin ketone models underwent oxidative Cα?Cβ bond cleavage and Cα?N bond formation to generate aromatic amides. For ammonia, the competition between oxygen and ammonia determined the selectivity between Cα?N and Cβ?N bond formation, generating amides and α-keto amides, respectively. For tertiary amines, the lignin models underwent oxidative Cα?Cβ bond cleavage to benzoic acids. Control experiments indicated that amines act as nucleophiles attacking at the Cα or Cβ position of the oxidized β-O-4 linkage to be cleaved. This study represents a novel example that the breakage of oxidized lignin model can be regulated by amines with a copper catalyst.
Double carbonylation of iodoarenes in the presence of a pyridinium SILP-Pd catalyst
Nagy, Enik?,Nagy, Petra,Papp, Máté,Skoda-F?ldes, Rita,Urbán, Béla
, (2020/04/28)
The efficiency of a palladium catalyst, immobilised on a supported ionic liquid phase (SILP) with adsorbed 1-butyl-4-methylpyridinium chloride, was investigated in aminocarbonylation reactions. Double carbonylation was found to be the main reaction using different iodoarenes and aliphatic amines as substrates. Application of aniline derivatives as nucleophiles led to the exclusive formation of substituted benzamides. The stabilisation effect of the adsorbed pyridinium ionic liquid was compared to that of imidazolium and phosphonium derivatives. It was proved that the pyridinium SILP-palladium catalyst could be reused in at least 10 cycles. Recyclability was tested in five successive runs for all of the substrates.
Metal-Free C=C Double Bond Cleavage on Enaminones for the Synthesis of α-Ketoamides by Free-Radical Aerobic Oxygenation
Yang, Yiming,Zhong, Guofeng,Fan, Junfen,Liu, Yunyun
supporting information, p. 4422 - 4425 (2019/06/24)
The tandem oxidation of the enaminone C=C double bond as well as subsequent C-N bond formation are realized under metal-free conditions by thermo-induced free radical transformation. In the presence of benzoyl peroxide (BPO) and N-iodosuccinimide (NIS), a
Development of palladium catalysts immobilized on supported phosphonium ionic liquid phases
Urbán, Béla,Skoda-F?ldes, Rita
, p. 302 - 306 (2018/12/04)
The application of heterogeneous palladium catalysts supported on phosphonium ion modified silica was investigated in aminocarbonylation reactions of aryl iodides. In contrast to catalysts immobilized on supports decorated with imidazolium ions, the application of phosphonium type supported ionic liquid phases made it possible to carry out double carbonylation with good selectivity in apolar toluene which led to a considerable decrease in the amount of leached palladium. An even better stabilization of the palladium catalyst could be achieved by introducing dicationic organic moieties incorporating both imidazolium and phosphonium ions on the surface of the support. At the same time, the former catalyst, obtained from the supported phosphonium ionic liquid phase was found to be superior in monocarbonylations. The amide products were obtained in good yields by the proper choice of the reaction conditions, such as reaction temperature and pressure and that of the base.
