7025-91-4Relevant academic research and scientific papers
Synthesis of N-heterocyclic carbene-Pd(II)-5-phenyloxazole complexes and initial studies of their catalytic activity toward the Buchwald-Hartwig amination of aryl chlorides
Zhang, Zhi-Mao,Xu, Yu-Ting,Shao, Li-Xiong
, (2021/04/19)
Three new N-heterocyclic carbene (NHC)-Pd(II) complexes using 5-phenyloxazole as the ancillary ligand have been obtained in moderate to good yields by a one-pot reaction of the corresponding imidazolium salts, palladium chloride and 5-phenyloxazole under mild conditions. Initial studies showed that one of the complexes is an efficient catalyst for the Buchwald-Hartwig amination of aryl chlorides with various secondary and primary amines under the varied catalyst loading of 0.01-0.05 mol%, thus it will enrich the chemistry of NHCs and give an alternative catalyst for the coupling of challenging while cost-low aryl chlorides.
Electrochemical Cross-Dehydrogenative Aromatization Protocol for the Synthesis of Aromatic Amines
Chen, Hua,Chen, Shan-Yong,Feng, Mei-Lin,Fu, Hai-Yan,Li, Rui-Xiang,Tao, Shao-Kun,Xu, Jia-Qi,Yu, Xiao-Qi,Yuan, Mao-Lin,Zheng, Xue-Li
supporting information, (2022/02/05)
The introduction of amines onto aromatics without metal catalysts and chemical oxidants is synthetically challenging. Herein, we report the first example of an electrochemical cross-dehydrogenative aromatization (ECDA) reaction of saturated cyclohexanones and amines to construct anilines without additional metal catalysts and chemical oxidants. This reaction exhibits a broad scope of cyclohexanones including heterocyclic ketones, affording a variety of aromatic amines with various functionalities, and shows great potential in the synthesis of biologically active compounds.
Effect of Precatalyst Oxidation State in C-N Cross-Couplings with 2-Phosphinoimidazole-Derived Bimetallic Pd(I) and Pd(II) Complexes
Martinez, Erin E.,Moreno, Mariur Rodriguez,Barksdale, Caleb A.,Michaelis, David J.
supporting information, p. 2763 - 2767 (2021/08/27)
We report the catalytic activity of two phosphinoimidazole-derived bimetallic palladium complexes in Pd-catalyzed amination reactions. Our studies demonstrate that the starting oxidation state (Pd(I) or Pd(II)) of the dimeric complex has a significant effect on the efficiency of the catalytic reaction. The corresponding Pd(I) complex shows higher reactivity in Buchwald-Hartwig aminations, while the Pd(II) complex is much more reactive in carbonylative amination reactions. These new dimeric palladium complexes provide good to excellent reactivity and yields in the amination reactions tested.
Amination of Aryl Halides Mediated by Electrogenerated Nickel from Sacrificial Anode
Daili, Farah,Sengmany, Stéphane,Léonel, Eric
, p. 2462 - 2469 (2021/06/28)
Electrochemical C(sp2)?N couplings mediated by nickel salts generated from the sacrificial anode has been described for the first time. In this approach, the sacrificial nickel anode is employed as the sole source of nickel and the process, operationally simple to set up, enables the preparation of functionalized arylamine derivatives with moderate to good yields, under mild reaction conditions and without additional ligand. A cooperative process between the two electrodes is involved in the proposed mechanism.
Ru(II)-Catalyzed Amination of Aryl Fluorides via η6-Coordination
Kang, Qi-Kai,Li, Yuntong,Lin, Yunzhi,Shi, Hang
supporting information, p. 3706 - 3711 (2020/03/11)
We developed a Ru/hemilabile-ligand-catalyzed nucleophilic aromatic substitution (SNAr) of aryl fluorides as the limiting reagents. Significant ligand enhancement was demonstrated by the engagement of both electron-rich and neutral arenes in the SNAr amination without using excess arenes. Preliminary mechanistic studies revealed that the nucleophilic substitution proceeds on a η6-complex of the Ru catalyst and the substrate, and the hemilabile ligand facilitates dissociation of products from the metal center.
Catalyst-free photodecarbonylation ofortho-amino benzaldehyde
Li, Lamei,Wang, Songping,Wei, Wentao,Yan, Ming,Zhou, Jingwei
supporting information, p. 3421 - 3426 (2020/06/25)
It is almost a consensus that decarbonylation of the aldehyde group (-CHO) needs to not only be mediated by transition metal catalysts, but also requires severe reaction conditions (high temperature and long reaction time). In this work, inspired by the “conformational-selectivity-based” design strategy, we broke this consensus and discovered a catalyst-free photodecarbonylation of the aldehyde group. It revealed that decarbonylation can be easily achieved with visible light irradiation by introducing a tertiary amine into theortho-position of the aldehyde group. A diverse array of tertiary amines is tolerated by our photodecarbonylation under mild conditions. Furthermore, the (QM) computations of the mechanism and the experiments on well-designed special substrates revealed that our photodecarbonylation depends on the conformational specificity of the aldehyde group and tertiary amine, and occurs through an unusual [1,4]-H shift and a subsequent [1,3]-H shift.
Nickel-Catalyzed Amination of Aryl Thioethers: A Combined Synthetic and Mechanistic Study
Bismuto, Alessandro,Delcaillau, Tristan,Müller, Patrick,Morandi, Bill
, p. 4630 - 4639 (2020/05/19)
Herein, we report a nickel-1,2-bis(dicyclohexylphosphino)ethane (dcype) complex for the catalytic Buchwald-Hartwig amination of aryl thioethers. The protocol shows broad applicability with a variety of different functional groups tolerated under the catalytic conditions. Extensive organometallic and kinetic studies support a nickel(0)-nickel(II) pathway for this transformation and revealed the oxidative addition complex as the resting state of the catalytic cycle. All the isolated intermediates have proven to be catalytically and kinetically competent catalysts for this transformation. The fleeting transmetalation intermediate has been successfully synthesized through an alternative synthetic organometallic pathway at lower temperature, allowing for in situ NMR study of the C-N bond reductive elimination step. This study addresses key factors governing the mechanism of the nickel-catalyzed Buchwald-Hartwig amination process, thus improving the understanding of this important class of reactions.
Photo-induced dealdehyding method
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Paragraph 0048-0053; 0102-0107, (2020/06/16)
The invention provides a photo-induced dealdehyding method, and belongs to the technical field of organic synthesis. The photo-induced dealdehyding method comprises the following steps that a mixtureof a compound shown in the formula I and a solvent are reacted under an inert gas atmosphere and visible light irradiation, a dealdehyding product is obtained, and no photocatalyst is used in the whole process; wherein the structural formula of the formula I shown in the specification, R is a functional group and is selected from hydrogen, methyl, methoxyl, cyano, chlorine, bromine or fluorine. According to the photo-induced dealdehyding method, in the inert gas atmosphere, the compound shown in the formula (I) can be excited to generate carbon-oxygen bond homogeneous cracking through visiblelight irradiation, then free radical migration and double bond displacement are conducted, finally carbon monoxide is removed, aldehyde group removal is completed, no photocatalyst is needed in the whole process, operation is easy and convenient, and conditions are mild.
Redox-neutral: Ortho -C-H amination of pinacol arylborates via palladium(ii)/norbornene catalysis for aniline synthesis
Chen, Shuqing,Wang, Peng,Cheng, Hong-Gang,Yang, Chihui,Zhou, Qianghui
, p. 8384 - 8389 (2019/09/30)
A palladium(ii)/norbornene cooperative catalysis enabled redox-neutral ortho-C-H amination of pinacol aryl- or heteroarylborates for the synthesis of structurally diverse anilines is reported. This method is scalable, robust (tolerance of air and moisture), phosphine ligand-free, and compatible with a wide range of functionalities. These practical features make this reaction amenable for industry. A plethora of synthetically very useful halogenated anilines, which often cannot be prepared via other transition-metal-catalyzed aminations, are readily produced using this method. Particularly, the orthogonal reactivity between pinacol arylborates and aryl iodides is demonstrated. Preliminary deuterium-labeling studies reveal a redox-neutral ipso-protonation mechanism of this process, which will surely inspire the future development of this field. Overall, the exceptionally broad scope (47 examples) and reliability of this procedure, together with the wide availability of pinacol arylborates, make this chemistry a valuable addition to the existing methods for aniline synthesis.
Aromatic amine compound, EphB4 kinase inhibitor and its derivatives, and preparation methods thereof
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Paragraph 0064-0066, (2019/11/04)
The invention provides an aromatic amine compound, an EphB4 kinase inhibitor and its derivatives, and preparation methods thereof. Aryl boronic acid or aryl boronate and O-benzoyl hydroxylamine compounds which are used as starting raw materials are stirred and reacted in an organic solvent at 30-100 DEG C in an air atmosphere under the action of a palladium catalyst, a norbornene derivative and analkali, and separation and purification are carried out after the reaction in order to obtain the aromatic amine compound. The method has the advantages of inexpensive and readily available raw materials, no halide ion residual after the completion of the reaction, and mild reaction conditions. The invention also provides the method for synthesizing the EphB4 kinase inhibitor and its derivatives.The EphB4 kinase inhibitor and its derivatives can be synthesized from the synthesized 3,5-diminated halogenobenzene or halogenoid benzene only through a simple step.
