56587-84-9Relevant academic research and scientific papers
Palladium-Catalyzed Regioselective Acylation of Diazines with Toluenes: A New Approach to the Synthesis of ortho-Diacylbenzenes
Afaridoun, Hadi,Kianmehr, Ebrahim,Seifinoferest, Behnoush
supporting information, (2020/08/13)
A highly efficient and practical procedure for chemo- and regioselective synthesis of ortho-diacylbenzenes through Pd-catalyzed oxidative C–H bond activation has been developed. Using this method, a variety of ortho-diacylbenzenes were prepared in moderate to good yields, by direct acylation of diazines with toluene derivatives as acylation source. Ortho-diacylbenzenes may be used as precursors in synthesis of pharmaceuticals and agrochemicals.
Cp*Co(III)-catalyzed C[sbnd]H amidation of azines with dioxazolones
Huang, Yanzhen,Pi, Chao,Tang, Zhen,Wu, Yangjie,Cui, Xiuling
supporting information, p. 3237 - 3240 (2020/09/15)
Cp*Co(III)-catalyzed direct C[sbnd]H amidation of azines has been developed. This conversion could proceed smoothly in the absence of external oxidants, acids or bases, with excellent regioselectivity and broad functional group tolerance. CO2 w
Cp*Co(iii)-catalyzed annulation of azines by C-H/N-N bond activation for the synthesis of isoquinolines
Deshmukh, Dewal S.,Yadav, Prashant A.,Bhanage, Bhalchandra M.
supporting information, p. 3489 - 3496 (2019/04/14)
Herein, an efficient, atom economic and external oxidant free approach has been disclosed for the synthesis of isoquinolines. Azines were employed for annulation reactions with alkynes via sequential C-H/N-N bond activation using an air-stable cobalt catalyst. The method takes advantage of the incorporation of both the nitrogen atoms of azines into the desired isoquinoline products, offering the highest atom economy. In addition, the developed protocol works under external oxidant as well as silver salt free conditions. Furthermore, the established methodology features a relatively broad substrate scope with high product yields and scalability up to the gram level.
Rapid and Atom Economic Synthesis of Isoquinolines and Isoquinolinones by C–H/N–N Activation Using a Homogeneous Recyclable Ruthenium Catalyst in PEG Media
Deshmukh, Dewal S.,Gangwar, Neha,Bhanage, Bhalchandra M.
supporting information, p. 2919 - 2927 (2019/05/10)
Herein, we report an atom-efficient, rapid, green, and sustainable approach to synthesize isoquinolines and isoquinolinones using a homogeneous recyclable ruthenium catalyst in PEG Media assisted by microwave energy. Dibenzoylhydrazine was used for C–H/N–N activation reactions for the first time in combination with ketazine as oxidizing directing groups for annulation reactions with internal alkynes. The developed protocol is environmentally benign due to significantly shortened times with an easy extraction method, higher atom economy, external oxidant and silver or antimony salt free conditions, applicability to a gram scale synthesis, use of biodegradable solvent and wide substrate scope with higher product yields. Moreover, it is worth noting that the established methodology allowed reuse of the catalytic system for up to five successive runs with minimal loss in activity.
One-pot synthesis of [1,2,4]Triazolo[1,5-a]pyridines from azines and benzylidenemalononitriles via copper-catalyzed tandem cyclization
Lv, Jianguang,He, Zhiqing,Zhang, Jianmin,Guo, Yuwei,Han, Ziwei,Bao, Xinhua
supporting information, p. 3996 - 4004 (2018/06/20)
A simple and efficient copper-catalyzed tandem radical cyclization reaction has been discovered for the synthesis of triaryl [1,2,4]triazolo[1,5-a]pyridines from easily accessible azines and benzylidenmalononitriles. The new transformation involves multip
Selective Reduction of Azines to Benzyl Hydrazones with Sodium Borohydride Catalyzed by Mesoporous Silica-Supported Silver Nanoparticles: A Catalytic Route towards Pyrazole Synthesis
Charistoudi, Evangelia,Kallitsakis, Michael G.,Charisteidis, Ioannis,Triantafyllidis, Kostas S.,Lykakis, Ioannis N.
supporting information, p. 2949 - 2960 (2017/09/08)
The catalytic activity of supported silver nanoparticles on mesoporous silica was studied, for the selective reduction of azines into benzyl hydrazones using sodium borohydride as mild reducing agent. Different sizes of silver nanoparticles supported on mesoporous silica (Ag/HMS) were successfully prepared by two methods, i.e., wet impregnation followed by reduction with hydrogen at 350 °C and in situ deposition/reduction with a mixture of amines (ethanolamine and ethylenediamine). The Ag/HMS (amines) catalyst was found to promote the selective 1,2-reduction of aryl-substituted azines, compared to the corresponding 1,4-reduction that occurs in general reduction processes. This catalytic transfer hydrogenation process found to be clean, fast and quantitative (>99% yields and selectivity) towards benzyl hydrazone synthesis under mild conditions. Of great importance is that under the present catalytic conditions reducible functional groups remain intact. Formal kinetics, support the in situ formation of silver hydride species being responsible for the reduction process. The presence of protic polar methanol enhanced the catalytic activity of Ag/HMS. Based on the recycling studies the catalytic system Ag/HMS-NaBH4 was found to catalyze the selective reduction of azines nine times without significant loss of its activity. Finally, a one-pot reaction between the in situ produced benzyl hydrazones and a series of nitrostyrenes readily provided the regioselective synthesis of 1,3,5-subtituted pyrazoles, highlighting a useful synthetic application of the catalytic protocol. (Figure presented.).
Rh-Catalyzed Regioselective ortho-C-H Carbenoid Insertion of Diarylazines
Yu, Yunliang,Kuai, Changsheng,Chauvin, Remi,Tian, Nian,Ma, Shuangshuang,Cui, Xiuling
, p. 8611 - 8616 (2017/08/23)
The Rh-catalyzed ortho-C-H carbenoid insertion reaction of diarylazines with diazo compounds has been developed. A wide range of ortho-substituted diarylazines have been obtained in moderate to high yields with high regioselectivity at room temperature. The hydrolysis of the products could release ketones or aldehydes, giving access to aromatic 1,5-keto-diesters as valuable synthons for further chemical transformations.
Cs2CO3-mediated decomposition of N-tosylhydrazones for the synthesis of azines under mild conditions
Luo, Zai-Gang,Liu, Peng,Fang, Yu-Yu,Xu, Xue-Mei,Feng, Cheng-Tao,Li, Zhong,Zhang, Xiao-Mei,He, Jie
, p. 1139 - 1148 (2017/02/10)
Abstract: A facile, environmentally and efficient Cs2CO3-mediated decomposition of N-tosylhydrazones reaction has been developed for the synthesis of functionalized azines under mild conditions. This method offers broad substrate scope, occurs as additive-free, without strong base conditions, utilizes readily available reactants, and forms products in good to high yields. Graphical Abstract: [Figure not available: see fulltext.]
Rhodium(III)-catalyzed coupling of aromatic ketazines or oximes with 2-vinyloxirane via C-H activation
Wen, Jing,Wu, An,Miao, Yuqin,Zhu, Jin
supporting information, p. 5512 - 5516 (2015/09/21)
Described herein is a rhodium(III)-catalyzed coupling of aromatic ketazines or oximes with 2-vinyloxirane via directed C-H activation. This reaction proceeds efficiently under mild conditions with a low catalyst loading, especially in conditions with room temperature in the absence of additives for aromatic ketazines. A wide range of substituted substrates is supported and a possible mechanism is proposed according to the experimental results of kinetic isotopic effect, reversibility studies, and catalysis with rhodacycle intermediate c1.
Rh-catalyzed sequential oxidative C-H and N-N bond activation: Conversion of azines into isoquinolines with air at room temperature
Han, Wenjia,Zhang, Guoying,Li, Guangxing,Huang, Hanmin
supporting information, p. 3532 - 3535 (2014/07/21)
A rhodium-catalyzed sequential oxidative C-H annulation reaction between ketazines and internal alkynes has been developed via C-H and N-N bond activation with air as an external oxidant, which led to an efficient approach toward isoquinolines with high atom efficiency at rt. Utilizing the distinctive reactivity of this catalysis, both N-atoms of the azines could be efficiently incorporated to the desired isoquinolines under very robust and mild reaction conditions.
