214360-48-2Relevant academic research and scientific papers
One-pot synthesis of new aza- and diaza-aminophenanthrenes
Rochais, Christophe,Yougnia, Rodrigue,Cailly, Thomas,Sopková-De Oliveira Santos, Jana,Rault, Sylvain,Dallemagne, Patrick
, p. 5806 - 5810 (2011)
The synthesis of a series of benzo(iso)quinoline and phenanthroline derivatives has been achieved using an efficient one-pot procedure. It proceeds through a Suzuki-Miyaura cross-coupling followed by a Dieckmann-Thorpe ring closure under microwave irradia
Palladium-catalyzed borylation of aryl bromides and chlorides using phosphatrioxa-adamantane ligands
Lamola, Jairus L.,Moshapo, Paseka T.,Holzapfel, Cedric W.,Christopher Maumela, Munaka
supporting information, (2021/12/13)
Catalysts based on the combination of Pd(OAc)2 and the electron-deficient phosphatrioxa-adamantane ligands are described for borylation of aryl bromides and chlorides. Catalytic evaluation of a small library of phosphatrioxa-adamantane ligands provided some insights on the preferred ligand steric profile for borylation reactions. The corresponding aryl boronate esters were accessed under mild conditions (25–70 °C) and isolated in high yields (up to 96%).
Unveiling Extreme Photoreduction Potentials of Donor-Acceptor Cyanoarenes to Access Aryl Radicals from Aryl Chlorides
Cao, Jilei,Tang, Xinxin,Toh, Ren Wei,Wang, Han,Wu, Jie,Wu, Xiangyang,Xu, Jinhui,Yang, Xiaona,Yeow, Edwin K. L.,Zhou, Rong
supporting information, p. 13266 - 13273 (2021/09/07)
Since the seminal work of Zhang in 2016, donor-acceptor cyanoarene-based fluorophores, such as 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN), have been widely applied in photoredox catalysis and used as excellent metal-free alternatives to noble metal Ir- and Ru-based photocatalysts. However, all the reported photoredox reactions involving this chromophore family are based on harnessing the energy from a single visible light photon, with a limited range of redox potentials from -1.92 to +1.79 V vs SCE. Here, we document the unprecedented discovery that this family of fluorophores can undergo consecutive photoinduced electron transfer (ConPET) to achieve very high reduction potentials. One of the newly synthesized catalysts, 2,4,5-tri(9H-carbazol-9-yl)-6-(ethyl(phenyl)amino)isophthalonitrile (3CzEPAIPN), possesses a long-lived (12.95 ns) excited radical anion form, 3CzEPAIPN?-*, which can be used to activate reductively recalcitrant aryl chlorides (Ered ≈ -1.9 to -2.9 V vs SCE) under mild conditions. The resultant aryl radicals can be engaged in synthetically valuable aromatic C-B, C-P, and C-C bond formation to furnish arylboronates, arylphosphonium salts, arylphosphonates, and spirocyclic cyclohexadienes.
peri-Xanthenoxanthene (PXX): a Versatile Organic Photocatalyst in Organic Synthesis
Pezzetta, Cristofer,Folli, Andrea,Matuszewska, Oliwia,Murphy, Damien,Davidson, Robert W. M.,Bonifazi, Davide
supporting information, p. 4740 - 4753 (2021/04/09)
Recent years have witnessed a continuous development of photocatalysts to satisfy the growing demand of photophysical and redox properties in photoredox catalysis, with complex structures or alternative strategies devised to access highly reducing or oxidising systems. We report herein the use of peri-xanthenoxanthene (PXX), a simple and inexpensive dye, as an efficient photocatalyst. Its highly reducing excited state allows activation of a wide range of substrates, thus triggering useful radical reactions. Benchmark transformations such as the addition of organic radicals, generated by photoreduction of organic halides, to radical traps are initially demonstrated. More complex dual catalytic manifolds are also shown to be accessible: the β-arylation of cyclic ketones is successful when using a secondary amine as organocatalyst, while cross-coupling reactions of aryl halides with amines and thiols are obtained when using a Ni co-catalyst. Application to the efficient two-step synthesis of the expensive fluoro-tetrahydro-1H-pyrido[4,3-b]indole, a crucial synthetic intermediate for the investigational drug setipiprant, has been also demonstrated. (Figure presented.).
Preparation method of o-nitrile phenylboronic acid-1, 3-propylene glycol ester
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Paragraph 0038-0039, (2021/01/29)
The invention discloses a preparation method of o-nitrile phenylboronic acid-1, 3-propylene glycol ester, which belongs to the technical field of organic boric acid chemistry. The method comprises thefollowing steps of starting from o-bromobenzonitrile, carrying out a one-pot reaction with borate/n-butyllithium or metal lithium/boron halide amine, after the reaction is detected to be finished, carrying out acidolysis to obtain 2-nitrile phenylboronic acid, or directly filtering, distilling, adding 1, 3-propylene glycol to form ester, pulping, and purifying to obtain the o-nitrile phenylboronic acid-1, 3-propylene glycol ester. The key point of the process is that the reaction liquid is added into the acid water for quenching after the reaction is finished, so that the condition that the acid water is added into a reaction system to be subjected to an alkaline environment first and then to an acid environment is avoided, the yield is kept stable in different amplification stages, and the process has an industrial amplification prospect. And corresponding boric acid ester can be smoothly obtained by replacing propylene glycol with other glycols.
Improvement in the Palladium-Catalyzed Miyaura Borylation Reaction by Optimization of the Base: Scope and Mechanistic Study
Barroso, Santiago,Joksch, Markus,Puylaert, Pim,Tin, Sergey,Bell, Stephen J.,Donnellan, Luke,Duguid, Stewart,Muir, Colin,Zhao, Peichao,Farina, Vittorio,Tran, Duc N.,De Vries, Johannes G.
supporting information, p. 103 - 109 (2020/12/22)
Aryl boronic acids and esters are important building blocks in API synthesis. The palladium-catalyzed Suzuki-Miyaura borylation is the most common method for their preparation. This paper describes an improvement of the current reaction conditions. By using lipophilic bases such as potassium 2-ethyl hexanoate, the borylation reaction could be achieved at 35 °C in less than 2 h with very low palladium loading (0.5 mol %). A preliminary mechanistic study shows a hitherto unrecognized inhibitory effect by the carboxylate anion on the catalytic cycle, whereas 2-ethyl hexanoate minimizes this inhibitory effect. This improved methodology enables borylation of a wide range of substrates under mild conditions.
Facile and economical Miyaura borylation and one-pot Suzuki–Miyaura cross-coupling reaction
Boontiem, Phongsakorn,Kiatisevi, Supavadee
, (2020/03/03)
Facile and economical method for Miyaura borylation reaction between B2pin2 and aryl bromides is reported. The catalytic system containing 2 mol% PdCl2(PPh3)2 and KOAc serves to enable borylations to occur under solvent-free and atmospheric conditions. The developed protocol can be applied to synthesize symmetrical and unsymmetrical biaryls via one-pot two-step Suzuki–Miyaura cross-coupling reaction and also offers the up-scalability.
Controllable factors of supported IR complex catalysis for aromatic C?H borylation
Chun, Wang-Jae,Maeda, Kyogo,Manaka, Yuichi,Motokura, Ken,Nakajima, Kiyotaka,Satter, Shazia Sharmin,Uemura, Yohei
, p. 14552 - 14559 (2020/12/21)
We have developed a catalyst in which an Ir complex and organic functionalities are coimmobilized on the silica surface. The catalytic activity for aromatic C?H borylation was significantly affected by (i) the linker length of the Ir?bipyridine complex, (ii) the coimmobilized organic functionality, and (iii) the substituents on the aromatic substrate compounds. The fine-tuned supported catalyst showed higher activity than the homogeneous Ir?bipyridine complex when using a specific substrate such as benzonitrile. We elucidated this property by conducting solid-state NMR, FT-IR, XAFS, and in situ FT-IR analysis.
Cleavage of C(aryl)?CH3 Bonds in the Absence of Directing Groups under Transition Metal Free Conditions
Dai, Peng-Fei,Ning, Xiao-Shan,Wang, Hua,Cui, Xian-Chao,Liu, Jie,Qu, Jian-Ping,Kang, Yan-Biao
supporting information, p. 5392 - 5395 (2019/03/29)
Organic chemists now can construct carbon–carbon σ-bonds selectively and sequentially, whereas methods for the selective cleavage of carbon–carbon σ-bonds, especially for unreactive hydrocarbons, remain limited. Activation by ring strain, directing groups, or in the presence of a carbonyl or a cyano group is usually required. In this work, by using a sequential strategy site-selective cleavage and borylation of C(aryl)?CH3 bonds has been developed under directing group free and transition metal free conditions. Methyl groups of various arenes are selectively cleaved and replaced by boryl groups. Mechanistic analysis suggests that it proceeds by a sequential intermolecular oxidation and coupling of a transient aryl radical, generated by radical decarboxylation, involving a pyridine-stabilized persistent boryl radical.
Photoinduced Miyaura Borylation by a Rare-Earth-Metal Photoreductant: The Hexachlorocerate(III) Anion
Qiao, Yusen,Yang, Qiaomu,Schelter, Eric J.
supporting information, p. 10999 - 11003 (2018/07/31)
The first photoinduced carbon(sp2)–heteroatom bond forming reaction by a rare-earth-metal photoreductant, a Miyaura borylation, has been achieved. This simple, scalable, and novel borylation method that makes use of the hexachlorocerate(III) anion ([CeIIICl6]3?, derived from CeCl3) has a broad substrate scope and functional-group tolerance and can be conducted at room temperature. Combined with Suzuki–Miyaura cross-coupling, the method is applicable to the synthesis of various biaryl products, including through the use of aryl chloride substrates.
