4253-79-6Relevant academic research and scientific papers
meta-C?H Bromination on Purine Bases by Heterogeneous Ruthenium Catalysis
Warratz, Svenja,Burns, David J.,Zhu, Cuiju,Korvorapun, Korkit,Rogge, Torben,Scholz, Julius,Jooss, Christian,Gelman, Dmitri,Ackermann, Lutz
, p. 1557 - 1560 (2017)
Methods for positionally selective remote C?H functionalizations are in high demand. Herein, we disclose the first heterogeneous ruthenium catalyst for meta-selective C?H functionalizations, which enabled remote halogenations with excellent site selectivity and ample scope. The versatile heterogeneous Ru@SiO2catalyst was broadly applicable and could be easily recovered and reused, which set the stage for the direct fluorescent labeling of purines. In contrast to palladium, rhodium, iridium, or cobalt complexes, solely the ruthenium catalysis manifold provided access to meta-halogenated purine derivatives, illustrating the unique power of ruthenium C?H activation catalysis.
Three-Component Couplings among Heteroarenes, Difluorocyclopropenes, and Water via C-H Activation
Liu, Xuexin,Chen, Jian,Yang, Chunyan,Wu, Zhouping,Li, Zhiyang,Shi, Yuesen,Huang, Tianle,Yang, Zhongzhen,Wu, Yong
supporting information, p. 6831 - 6835 (2021/09/08)
Three-component couplings have been realized for efficiently constructing various nitrogen-containing skeletons via C-H activation, where difluorocyclopropenes have been first identified as coupling partners. Many substrates including sp2 and sp3 C-H substrates were well tolerated, furnishing the corresponding products in good yields. Furthermore, a catalyst-dependent reaction was also developed, enabling divergent construction of two different frameworks. The application value of these reactions was demonstrated in gram-scale experiments with as little as 1 mol % catalyst.
Photoarylation of Pyridines Using Aryldiazonium Salts and Visible Light: An EDA Approach
Bartolomeu, Aloisio De A.,Brocksom, Timothy J.,De Oliveira, Kleber T.,No?l, Timothy,Silva, Rodrigo C.
, (2019/08/26)
A metal-free methodology for the photoarylation of pyridines, in water, is described giving 2 and 4-arylated-pyridines in yields up to 96percent. The scope of the aryldiazonium salts is presented showing important results depending on the nature and position of the substituent group in the diazonium salt, that is, electron-donating or electron-withdrawing in the ortho, meta, or para positions. Further heteroaromatics were also successfully photoarylated. Mechanistic studies and comparison between our methodology and similar metal-catalyzed procedures are presented, suggesting the occurrence of a visible-light EDA complex which generates the aryl radical with no need for an additional photocatalyst.
Enabling Catalytic Arene C-H Amidomethylation via Bis(tosylamido)methane as a Sustainable Formaldimine Releaser
Li, Zhong-Yuan,Chaminda Lakmal, Hetti Handi,Cui, Xin
supporting information, p. 3735 - 3740 (2019/05/24)
Addition of catalytic arene C-H to formaldimines has been enabled by Ru(II)-catalyzed amidomethylation with bis(tosylamido)methane as a catalytic formaldimine releaser. The new process provides an atom-efficient and sustainable solution to address the challenges of formaldimines in this type of transformation. Furthermore, new synthetic routes based on this catalytic system have been developed for step-efficient access to N-heterotricyclic core structures that are pharmaceutically relevant.
DIARYLUREAS AS CB1 ALLOSTERIC MODULATORS
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Paragraph 69; 72; 76, (2018/12/02)
The present invention provides novel diarylurea derivatives (compounds of formula (I)) and their uses. The compounds of the present invention are demonstrated to be allosteric modulators of the CB1 receptor, and therefore useful for the treatment of diseases and conditions mediated by CB1.
Novel Diarylurea Based Allosteric Modulators of the Cannabinoid CB1 Receptor: Evaluation of Importance of 6-Pyrrolidinylpyridinyl Substitution
Nguyen, Thuy,German, Nadezhda,Decker, Ann M.,Langston, Tiffany L.,Gamage, Thomas F.,Farquhar, Charlotte E.,Li, Jun-Xu,Wiley, Jenny L.,Thomas, Brian F.,Zhang, Yanan
, p. 7410 - 7424 (2017/09/22)
Allosteric modulators of the cannabinoid CB1 receptor have recently been reported as an alternative approach to modulate the CB1 receptor for therapeutic benefits. In this study, we report the design and synthesis of a series of diarylureas derived from PSNCBAM-1 (2). Similar to 2, these diarylureas dose-dependently inhibited CP55,940-induced intracellular calcium mobilization and [35S]GTP-γ-S binding while enhancing [3H]CP55,940 binding to the CB1 receptor. Structure-activity relationship studies revealed that the pyridinyl ring of 2 could be replaced by other aromatic rings and the pyrrolidinyl ring is not required for CB1 allosteric modulation. 34 (RTICBM-74) had similar potencies as 2 in all in vitro assays but showed significantly improved metabolic stability to rat liver microsomes. More importantly, 34 was more effective than 2 in attenuating the reinstatement of extinguished cocaine-seeking behavior in rats, demonstrating the potential of this diarylurea series as promising candidates for the development of relapse treatment of cocaine addiction.
Synthesis of 2-phenyl pyridine derivatives from aryl ketones and 1,3-diaminopropane using palladium acetate as a catalyst
Ghodse, Shrikant M.,Telvekar, Vikas N.
supporting information, p. 524 - 526 (2017/01/17)
A simple and efficient method for the synthesis of 2-phenyl pyridine via cyclization of aryl ketone with 1,3-diaminopropane using palladium acetate is established. This method is mild, operationally simple, involves short reaction time and involves easy workup procedure to afford the corresponding 2-phenyl pyridines in moderate to good yield.
Method for preparing Vismodegib
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Paragraph 0155-0157, (2017/04/28)
The invention provides a preparation method for vismodegib, and in other words, a preparation method for 2-chloro-N-(4-chloro-3-(pyridin-2-yl)-phenyl)-4-(methylsulfonyl)benzamide. The method comprises: firstly preparing an intermediate 2-(3-nitrophenyl)py
Meta-Selective CAr-H Nitration of Arenes through a Ru3(CO)12-Catalyzed Ortho-Metalation Strategy
Fan, Zhoulong,Ni, Jiabin,Zhang, Ao
supporting information, p. 8470 - 8475 (2016/07/26)
The first example of transition metal-catalyzed meta-selective CAr-H nitration of arenes is described. With the use of Ru3(CO)12 as the catalyst and Cu(NO3)2·3H2O as the nitro source, a wide spectrum of arenes bearing diversified N-heterocycles or oximido as the directing groups were nitrated with meta-selectivity exclusively. Mechanism studies have demonstrated the formation of a new 18e-octahedral ruthenium species as a key ortho-CAr-H metalated intermediate, which may be responsible for the subsequent meta-selective electrophilic aromatic substitution (SEAr). Moreover, this approach provides a fast-track strategy for atom/step economical synthesis of many useful pharmaceutical molecules.
Chemoselective Synthesis of Polysubstituted Pyridines from Heteroaryl Fluorosulfates
Zhang, Enxuan,Tang, Jiaze,Li, Suhua,Wu, Peng,Moses, John E.,Sharpless, K. Barry
supporting information, p. 5692 - 5697 (2016/04/20)
A selection of heteroaryl fluorosulfates were readily synthesized using commercial SO2F2 gas. These substrates are highly efficient coupling partners in the Suzuki reaction. Through judicious selection of Pd catalysts the fluorosulfate functionality is differentiated from bromide and chloride; the order of reactivity being: -Br> -OSO2F> -Cl. Exploiting this trend allowed the stepwise chemoselective synthesis of a number of polysubstituted pyridines, including the drug Etoricoxib. A selection of heteroaryl fluorosulfates were readily synthesized using commercial SO2F2 gas. These substrates are highly efficient coupling partners in the Suzuki reaction. Through judicious selection of Pd catalysts the fluorosulfate functionality is differentiated from bromide and chloride; the order of reactivity being: -Br> -OSO2F> -Cl. Exploiting this trend allowed the stepwise chemoselective synthesis of a number of polysubstituted pyridines, including the drug Etoricoxib.
