92-71-7Relevant academic research and scientific papers
Thiocarbamate-directed Cp*Co(III)-Catalyzed Olefinic C?H Amidation: Facile Access to Enamines with High (Z)-Selectivity
Liang, Ya-Ru,Si, Xiao-Ju,Zhang, He,Yang, Dandan,Niu, Jun-Long,Song, Mao-Ping
, p. 694 - 700 (2021)
A thiocarbamate-directed Cp*Co(III)-catalyzed C?H oxidative amidation of olefins is achieved to synthesize a series of enamines. The key feature of this protocol is the use of earth-abundant cobalt as catalyst and thiocarbamate as directing group, which provides an efficient and simple manner to synthesize enamines in good yields with high (Z)-selectivity. This reaction proceeds smoothly under very mild conditions (rt and air), and a wide range of functionalized alkenes, as well as dioxazolones, were compatible with the standard reaction conditions.
Pd/Cu-Catalyzed C-H/C-H Cross Coupling of (Hetero)Arenes with Azoles through Arylsulfonium Intermediates
Lin, Zeng-Hui,Tian, Ze-Yu,Zhang, Cheng-Pan
supporting information, p. 4400 - 4405 (2021/06/27)
A highly efficient method for the selective formal C-H/C-H cross-coupling of azoles and (hetero)arenes was established through arylsulfonium intermediates under transition-metal catalysis, which produced a variety of 2-(hetero)aryl azoles in good to excellent yields. Advantages of the reaction included mildness, a good functional group tolerance, a wide range of substrates, a high regio- and chemoselectivity, one-pot procedures, and the late-stage functionalization of complex molecules without the use of oxidants, offering a promising strategy for the transition-metal-catalyzed C-H arylation of azoles.
Bimetallic Cooperative Catalysis for Decarbonylative Heteroarylation of Carboxylic Acids via C-O/C-H Coupling
Liu, Chengwei,Ji, Chong-Lei,Zhou, Tongliang,Hong, Xin,Szostak, Michal
supporting information, p. 10690 - 10699 (2021/04/09)
Cooperative bimetallic catalysis is a fundamental approach in modern synthetic chemistry. We report bimetallic cooperative catalysis for the direct decarbonylative heteroarylation of ubiquitous carboxylic acids via acyl C-O/C-H coupling. This novel catalytic system exploits the cooperative action of a copper catalyst and a palladium catalyst in decarbonylation, which enables highly chemoselective synthesis of important heterobiaryl motifs through the coupling of carboxylic acids with heteroarenes in the absence of prefunctionalization or directing groups. This cooperative decarbonylative method uses common carboxylic acids and shows a remarkably broad substrate scope (>70 examples), including late-stage modification of pharmaceuticals and streamlined synthesis of bioactive agents. Extensive mechanistic and computational studies were conducted to gain insight into the mechanism of the reaction. The key step involves intersection of the two catalytic cycles via transmetallation of the copper–aryl species with the palladium(II) intermediate generated by oxidative addition/decarbonylation.
Synthesis of α-Amidoketones through the Cascade Reaction of Carboxylic Acids with Vinyl Azides under Catalyst-Free Conditions
Gao, Cai,Zhou, Qianting,Yang, Li,Zhang, Xinying,Fan, Xuesen
, p. 13710 - 13720 (2020/11/13)
An efficient synthesis of α-amidoketone derivatives through the cascade reactions of carboxylic acids with vinyl azides is presented. Compared with literature protocols, notable features of this new method include catalyst-free conditions, broad substrate scope, good tolerance of a wide range of functional groups, and high efficiency. In addition, the synthetic potential of this method as a tool for late-stage modification was convincingly manifested by its application in the structural elaborations of a number of carboxylic acid drug molecules.
Photoinduced Heterogeneous C?H Arylation by a Reusable Hybrid Copper Catalyst
Choi, Isaac,Müller, Valentin,Lole, Gaurav,K?hler, Robert,Karius, Volker,Vi?l, Wolfgang,Jooss, Christian,Ackermann, Lutz
supporting information, p. 3509 - 3514 (2020/03/03)
Heterogeneous copper catalysis enabled photoinduced C?H arylations under exceedingly mild conditions at room temperature. The versatile hybrid copper catalyst provided step-economical access to arylated heteroarenes, terpenes and alkaloid natural products with various aryl halides. The hybrid copper catalyst could be reused without significant loss of catalytic efficacy. Detailed studies in terms of TEM, HRTEM and XPS analysis of the hybrid copper catalyst, among others, supported its outstanding stability and reusability.
Synthesis method of alpha-acylamino ketone compound
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Paragraph 0151-0154, (2020/12/08)
The invention discloses a synthesis method of an alpha-acylamino ketone compound, and belongs to the technical field of organic synthesis. The preparation method comprises the following steps: mixingan alkenyl azide compound 1, a carboxylic acid compound 2 and an organic solvent, and heating to react to obtain the alpha-acylamino ketone compound 3. Compared with the prior art, the method has thefollowing advantages: (1) the synthesis process is simple and efficient, no catalyst is needed in the whole process, and the alpha-acylamino ketone compound can be obtained with high yield by dissolving the alkenyl azide compound and the carboxylic acid compound in the solvent and stirring; (2) raw materials are cheap and easy to obtain, reaction conditions are mild, and operation is simple; (3) the substrate is wide in application range and can be used for modifying drug molecules; and (4) the atom economy is high, and the requirements of green chemistry are met.
Synthesis method of oxazole heterocyclic compound
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, (2020/04/17)
The invention belongs to the technical field of organic synthesis and medicines, and particularly relates to a synthesis method of an oxazole heterocyclic compound. Aryl aldehyde and a triazole derivative are used as raw materials and are heated to react in the presence of trichloromethane and rhodium acetate catalysts to obtain the oxazole heterocyclic compound. By using the method provided by the invention, under the condition of heating and stirring, the oxazole heterocyclic derivative can be obtained at a relatively high yield after reaction for 3-12 hours. According to the method disclosed by the invention, the oxazole heterocyclic derivative is simply, conveniently and efficiently synthesized by using simple and easily available raw materials through a one-step method, and a simple and efficient new synthesis method with wide substrate universality is provided for synthesizing the oxazole heterocyclic derivative.
Synthesis of 2,5-diaryloxazoles through rhodium-catalyzed annulation of triazoles and aldehydes
Li, Jian,Liu, Li,Lu, Xue-Chen,Wang, Zheng-Bing,Xu, De-Feng,Xu, Yue,Zhu, Shang-Rong
, p. 24795 - 24799 (2020/07/14)
An efficient synthesis of a variety of 2,5-diaryloxazole derivatives via a rhodium-catalyzed annulation of triazoles and aldehydes is achieved. Various oxazole derivatives could be obtained in good to excellent yields. A concise synthesis of antimycobaterial natural products balsoxin and texamine has been achieved using this method. This journal is
Reaction Conditions for the Regiodivergent Direct Arylations at C2- or C5-Positions of Oxazoles using Phosphine-Free Palladium Catalysts
Shi, Xinzhe,Soulé, Jean-Fran?ois,Doucet, Henri
, p. 4748 - 4760 (2019/09/12)
Two sets of reaction conditions for the regiodivergent C2- or C5- direct arylations of oxazole are reported. In both cases, phosphine-free catalysts and inexpensive bases were employed allowing the access to the arylated oxazoles in moderate to high yields. Using Pd(OAc)2/KOAc as catalyst and base, regioselective C5-arylations were observed; whereas, using Pd(acac)2/Cs2CO3 system, the arylation occurred at the C2-position of oxazole. The higher reactivity of C5-H bond of oxazole as compared to the C2-H bond in the presence of Pd(OAc)2/KOAc system is consistent with a concerted metalation deprotonation mechanism; whereas the C2-arylation likely occurs via a simple base deprotonation of the oxazole C2-position. Then, from these C2- or C5-arylated oxazoles, a second palladium-catalyzed direct C?H bond arylation affords 2,5-diaryloxazoles with two different aryl groups. We also applied these sequential arylations to the straightforward synthesis of 2-arylphenanthro[9,10-d]oxazoles via three C?H bond functionalization steps. The Ru-catalyzed C?H arylation of the aryl unit of 2-aryloxazoles is also described. (Figure presented.).
Divergent Conversion of N-Acyl-isoxazol-5(2 H)-ones to Oxazoles and 1,3-Oxazin-6-ones Using Photoredox Catalysis
Mei, Mingjing,Anand, Devireddy,Zhou, Lei
, p. 3548 - 3553 (2019/05/24)
The fragmentation of N-acyl-isoxazol-5-ones using visible light photoredox catalysis has been disclosed. The catalyst-controlled divergent mechanisms, namely the oxidative and reductive quenching catalytic cycle, are utilized. Various oxazoles and 1,3-oxazin-6-ones are selectively obtained from the same isoxazol-5-one skeleton under mild conditions.
