92017-95-3Relevant academic research and scientific papers
Mo–Catalyzed One-Pot Synthesis of N-Polyheterocycles from Nitroarenes and Glycols with Recycling of the Waste Reduction Byproduct. Substituent-Tuned Photophysical Properties
Hernández-Ruiz, Raquel,Rubio-Presa, Rubén,Suárez-Pantiga, Samuel,Pedrosa, María R.,Fernández-Rodríguez, Manuel A.,Tapia, M. José,Sanz, Roberto
, p. 13613 - 13623 (2021/08/23)
A catalytic domino reduction–imine formation–intramolecular cyclization–oxidation for the general synthesis of a wide variety of biologically relevant N-polyheterocycles, such as quinoxaline- and quinoline-fused derivatives, and phenanthridines, is reported. A simple, easily available, and environmentally friendly dioxomolybdenum(VI) complex has proven to be a highly efficient and versatile catalyst for transforming a broad range of starting nitroarenes involving several redox processes. Not only is this a sustainable, step-economical as well as air- and moisture-tolerant method, but also it is worth highlighting that the waste byproduct generated in the first step of the sequence is recycled and incorporated in the final target molecule, improving the overall synthetic efficiency. Moreover, selected indoloquinoxalines have been photophysically characterized in cyclohexane and toluene with exceptional fluorescence quantum yields above 0.7 for the alkyl derivatives.
Copper catalysed Gomberg-Bachmann-Hey reactions of arenediazonium tetrafluoroborates and heteroarenediazonium o-benzenedisulfonimides. Synthetic and mechanistic aspects
Antenucci, Achille,Barbero, Margherita,Dughera, Stefano,Ghigo, Giovanni
, (2020/10/20)
Gomberg-Bachmann-Hey reactions were carried out in the presence of copper as a catalyst and gave rise to biaryls or heterobiaryls in good yields and in mild reaction conditions. A computational study of some key points of the reaction was performed. The results are coherent with the experimental data and confirm some aspects of the mechanism. The reaction free energies for the reduction in benzene by CuI of a set of 40 (hetero)arenediazonium tetrafluoroborates were calculated. Both the experiments and the calculations showed that in the coupling with substituted solvents (toluene, bromobenzene, nitrobenzene and anisole) the binding to the ortho position was always favoured.
Highly efficient palladium-catalyzed cross-coupling of diarylborinic acids with arenediazoniums for practical diaryl synthesis
Wang, Fengze,Wang, Chen,Sun, Guoping,Zou, Gang
, (2019/12/25)
A highly efficient cross-coupling of cost-effective diarylborinic acids with both isolatable and latent arenediazoniums, i.e. tetrafluoroborates and aryltriazenes, respectively, has been developed with a practical palladium catalyst system under base-free conditions in open flask at room temperature. A variety of electronically and sterically various biaryls, in particular, those bearing a coordinative ortho-substituent, could be obtained in good to excellent yields by using 0.3 mol% palladium acetate as catalyst. Features of the protocol including cost-effectiveness of diarylborinic acids, efficacy to heteroatom ortho-substituted substrates and high chemoselectivity to aryl chlorides have been clearly demonstrated in practical synthesis of fungicide Boscalid.
Tetramethylammonium fluoride tetrahydrate-mediated transition metal-free coupling of aryl iodides with unactivated arenes in air
Nozawa-Kumada, Kanako,Nakamura, Kosuke,Kurosu, Satoshi,Iwakawa, Yuki,Denneval, Charline,Shigeno, Masanori,Kondo, Yoshinori
, p. 1042 - 1045 (2019/10/02)
Biaryls are important compounds with widespread applications in many fields. Tetramethylammonium fluoride tetrahydrate was found to promote the biaryl coupling of aryl iodides bearing electron-withdrawing substituents with unactivated arenes. The reaction takes place at temperatures between 100 and 150°C and can be applied to a wide range of aromatic and heteroaromatic rings, affording the products in moderate to high yields. The reaction does not require strong bases or expensive additives that are employed in the existing methods and can be conducted in air and moisture without any precautions.
An active catalytic system for Suzuki-Miyaura cross-coupling reactions using low levels of palladium loading
Yan, Meng-Qi,Yuan, Jia,Lan, Fang,Zeng, Si-Hao,Gao, Meng-Yue,Liu, Sheng-Hua,Chen, Jian,Yu, Guang-Ao
supporting information, p. 3924 - 3929 (2017/07/10)
An easily available Pd(OAc)2/(2-(anthracen-9-yl)-1H-inden-3-yl) dicyclohexylphosphine/toluene/iPrOH/water catalytic system was developed, which shows high catalytic activity in the Suzuki-Miyaura cross-coupling reactions of a diverse array of aryl and heteroaryl chlorides with Pd loadings down to 0.01 mol%.
Synthesis of Biaryls by Decarboxylative Hiyama Coupling
Katayev, Dmitry,Exner, Benjamin,Goossen, Lukas J.
, p. 2028 - 2032 (2015/11/24)
A trimetallic palladium/copper/silver system has been developed that allows the decarboxylative Hiyama coupling of ortho-substituted aryl carboxylates with trialkoxyarylsilanes to give the corresponding biaryls. The cross-coupling is catalyzed by a Pd/N-heterocyclic carbene complex with silver carbonate aiding its reoxidation. Copper(II) fluoride acts as decarboxylation catalyst, stoichiometric oxidant, and fluoride source. The scope of the protocol is demonstrated by 22 examples, among them aryl halides suitable for further coupling, and the synthetic utility of the products is illustrated by their conversion into carbazoles and 1H-indazoles.
Transition-metal-free synthesis of phenanthridinones from biaryl-2-oxamic acid under radical conditions
Yuan, Ming,Chen, Li,Wang, Junwei,Chen, Shenjie,Wang, Kongchao,Xue, Yongbo,Yao, Guangmin,Luo, Zengwei,Zhang, Yonghui
, p. 346 - 349 (2015/02/19)
Na2S2O8-promoted decarboxylative cyclization of biaryl-2-oxamic acid for phenanthridinones has been developed. This work illustrates the first example of intramolecular decarboxylative amidation of unactivated arene under transition-metal-free conditions. Additionally, this approach provides an efficient and economical method to access biologically interesting phenanthridinones, an important structure motif in many natural products. (Chemical Equation Presented).
Rapid synthesis of fused N-heterocycles by transition-metal-free electrophilic amination of arene C-H bonds
Gao, Hongyin,Xu, Qing-Long,Yousufuddin, Muhammed,Ess, Daniel H.,Kuerti, Laszlo
supporting information, p. 2701 - 2705 (2014/03/21)
We disclose an efficient and operationally simple protocol for the preparation of fused N-heterocycles starting from readily available 2-nitrobiaryls and PhMgBr under mild conditions. More than two dozen N-heterocycles, including two bioactive natural products, have been synthesized using this method. A stepwise electrophilic aromatic cyclization mechanism was proposed by DFT calculations. Controlled fusion: A transition-metal-free, low-temperature, and regioselective intramolecular amination of aromatic C(sp2)-H bonds provides fused N-heterocycles. This reaction is operationally simple and scalable (1-10 mmol) and the scope of substrates is wide (see scheme). Density functional calculations indicate that a stepwise electrophilic aromatic cyclization mechanism may be operative.
Decarboxylative cross-coupling of mesylates catalyzed by copper/palladium systems with customized imidazolyl phosphine ligands
Song, Bingrui,Knauber, Thomas,Goo?en, Lukas J.
, p. 2954 - 2958 (2013/04/11)
The activation of the inert C-O bonds in mesylates through the use of a new class of imidazolyl phosphines allows the decarboxylative coupling of aryl mesylates as well as polysubstituted alkenyl mesylates. Variation of the ligands leads to two complementary methods providing the corresponding biaryls and polysubstituted olefins in good yields. Copyright
Decarboxylative cross-coupling of aryl tosylates with aromatic carboxylate salts
Goossen, Luksa J.,Rodriguez, Nuria,Lange, Paul P.,Linder, Christophe
supporting information; experimental part, p. 1111 - 1114 (2010/04/29)
(Figure Presented) A bimetallic copper/palladium catalyst system is disclosed that enables the use of tosylates as carbon electrophiles in decarboxylative coupling reactions. A variety of aromatic carboxylate salts, regardless of their substitution pattern, have been coupled with these inexpensive and readily available electrophiles to give the corresponding biaryl compounds in good yields (see scheme).
