4545-18-0Relevant academic research and scientific papers
Copper-catalyzed tri- or tetrafunctionalization of alkenylboronic acids to prepare tetrahydrocarbazol-1-ones and indolo[2,3-a]carbazoles
Bi, Hong-Yan,Li, Cheng-Jing,Liang, Cui,Mo, Dong-Liang,Wei, Cui
supporting information, p. 5815 - 5821 (2020/09/21)
We describe a cascade strategy for tri- or tetrafunctionalization of alkenylboronic acids to prepare diverse tetrahydrocarbazol-1-ones and indolo[2,3-a]carbazoles in good yields withN-hydroxybenzotriazin-4-one (HOOBT) and arylhydrazines as oxygen and nitrogen sources, respectively. Mechanistic studies reveal that the domino reaction undergoes the copper-catalyzed Chan-Lam reaction, [2,3]-rearrangement, nucleophilic substitution, oxidation and sequential [3,3]-rearrangement over five steps in a one-pot reaction. The reaction shows a broad substrate scope and tolerates a wide range of functional groups. More importantly, the reaction is easily performed at gram scales and the product is purified by simple extraction, washing, and recrystallization without flash column chromatography. The present protocol features easily available starting materials, high site-marked functionalization, five-step cascade in one pot, multiple C-C/C-O/C-N bond formation, and diversity of indole motifs.
Preparation method of allylboronic acid pinacol ester
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Paragraph 0006, (2019/04/06)
The invention provides a common preparation method of allylboronic acid pinacol ester. The common preparation method takes aliphatic ketone as a raw material and comprises the following steps: takingaliphatic ketone and p-toluenesulfonohydrazide as raw ma
Pd-Catalyzed Heck-Type Reaction: Synthesizing Highly Diastereoselective and Multiple Aryl-Substituted P-Ligands
Li, Chong,Qiang, Xiao-Yue,Qi, Zhi-Chao,Cao, Bin,Li, Jing-Yu,Yang, Shang-Dong
supporting information, p. 7138 - 7142 (2019/09/30)
In this work, an efficient palladium-catalyzed Heck-type reaction was successfully used to synthesize a wide range of monoaryl-or diaryl-substituted P-ligands with excellent yields and diastereoselectivity (up to 98% yield, dr >20:1). The preliminary mechanistic studies demonstrated that it possibly underwent a cationic Heck reaction that was assisted by silver salt, and it revealed the significant role of P(O)Ar2 for excellent yields and diastereoselectivity.
Palladium-Catalyzed Cross-Coupling of gem-Bis(boronates) with Aryl Halides: An Alternative to Access Quaternary α-Aryl Aldehydes
Zheng, Purui,Zhai, Yujie,Zhao, Xiaoming,Xu, Tao
supporting information, p. 393 - 396 (2019/01/23)
The compounds with a quaternary α-aryl aldehyde skeleton are important units in organic chemistry. Previously, the aryl group and carbonyl group are introduced in a stepwise manner. Herein, a novel route is developed to construct the quaternary α-aryl aldehydes with gem-bis(boronates) as precursors, in which the two groups are installed simultaneously. The gem-bis(boronates) are readily available from ketones; as a result, this methodology provides a more general strategy to produce the quaternary α-aryl aldehydes with broad scopes and synthetic convenience.
Copper-catalyzed one-pot coupling reactions of aldehydes (ketones), tosylhydrazide and 2-amino(benzo)thiazoles: An efficient strategy for the synthesis of N-alkylated (benzo)thiazoles
Xie, Zengyang,Chen, Ruijiao,Ma, Mingfang,Kong, Lingdong,Liu, Jun,Wang, Cunde
, (2019/08/16)
An efficient and practical C–N bond formation methodology for the synthesis of N-alkylated (benzo)thiazoles was developed, via the copper-catalyzed one-pot two-step reactions of 2-amino(benzo)thiazoles and aldehydes (ketones) with tosylhydrazide. This cross-coupling reaction proceeded smoothly and tolerated a broad range of functional groups (46 examples). A variety of functionalized N-alkylated (benzo)thiazoles were obtained in moderate to high yields. Notably, gram-scale synthesis of fanetizole (anti-inflammatory drug) was also realized through this protocol.
Development of pyrazole and spiropyrazoline analogs as multifunctional agents for treatment of Alzheimer's disease
Gutti, Gopichand,Kumar, Devendra,Paliwal, Pankaj,Ganeshpurkar, Ankit,Lahre, Khemraj,Kumar, Ashok,Krishnamurthy, Sairam,Singh, Sushil Kumar
, (2019/07/03)
Cholinergic hypothesis of Alzheimer's disease has been advocated as an essential tool in the last couple of decades for the drug development. Here in, we report de novo fragment growing strategy for the design of novel 3,5-diarylpyrazoles and hit optimization of spiropyrazoline derivatives as acetyl cholinesterase inhibitors. Both type of scaffolds numbering forty compounds were synthesized and evaluated for their potencies against AChE, BuChE and PAMPA. Introduction of lipophilic cyclohexane ring in 3,5-diarylpyrazole analogs led to spiropyrazoline derivatives, which facilitated and improved the potencies. Compound 44 (AChE = 1.937 ± 0.066 μM; BuChE = 1.166 ± 0.088 μM; hAChE = 1.758 ± 0.095 μM; Pe = 9.491 ± 0.34 × 10?6 cm s1) showed positive results, which on further optimization led to the development of compound 67 (AChE = 0.464 ± 0.166 μM; BuChE = 0.754 ± 0.121 μM; hAChE = 0.472 ± 0.042 μM; Pe = 13.92 ± 0.022 × 10?6 cm s1). Compounds 44 and 67 produced significant displacement of propidium iodide from the peripheral anionic site (PAS) of AChE. They were found to be safer to MC65 cells and decreased metal induced Aβ1-42 aggregation. Further, in-vivo behavioral studies, on scopolamine induced amnesia model, the compounds resulted in better percentage spontaneous alternation scores and were safe, had no influence on locomotion in tested animal groups at dose of 3 mg/kg. Early pharmacokinetic assessment of optimized hit molecules was supportive for further drug development.
Lewis Acid Catalyzed [4 + 2] Cycloaddition of N-Tosylhydrazones with ortho-Quinone Methides
Wang, Chun-Ying,Han, Jia-Bin,Wang, Long,Tang, Xiang-Ying
, p. 14258 - 14269 (2019/11/11)
A formal [4 + 2] cycloaddition of N-tosylhydrazones with ortho-quinone methides was developed, affording the facile synthesis of diverse 1,3-oxazine derivatives under mild conditions. In this transformation, N-tosylhydrazones are used as a 1,2-dipole synt
Rapid Synthesis of N-Tosylhydrazones under Solvent-Free Conditions and Their Potential Application Against Human Triple-Negative Breast Cancer
Xie, Zengyang,Song, Yuying,Xu, Lujia,Guo, Yukun,Zhang, Min,Li, Limei,Chen, Kai,Liu, Xue
, p. 977 - 983 (2018/11/27)
Some N-tosylhydrazone derivatives were effectively synthesized under solvent-free conditions by using a grinding method at room temperature. The short reaction time, clean and mild process with simple workup and easy purification of the target compounds w
A cascade Claisen rearrangement/o-quinone methide formation/electrocyclization approach to 2H-chromenes
Song, Liyan,Huang, Fang,Guo, Liwen,Ouyang, Ming-An,Tong, Rongbiao
supporting information, p. 6021 - 6024 (2017/07/10)
A new approach has been developed for the synthesis of 8-substituted 2H-chromenes, featuring a novel cascade aromatic Claisen rearrangement/o-quinone methide formation/6π-electrocyclization. This new method was demonstrated with 28 examples tolerating different substitutions at alkenes, allylic and aromatic ring and with total syntheses of three 2H-chromene natural products.
Zinc-promoted cyclization of tosylhydrazones and 2-(dimethylamino)malononitrile: An efficient strategy for the synthesis of substituted 1-tosyl-1: H -pyrazoles
Zhang, Bang-Hong,Lei, Lin-Sheng,Liu, Si-Zhan,Mou, Xue-Qing,Liu, Wei-Ting,Wang, Shao-Hua,Wang, Jie,Bao, Wen,Zhang, Kun
supporting information, p. 8545 - 8548 (2017/08/04)
A Zn(OTf)2-promoted cyclization reaction of tosylhydrazones with 2-(dimethylamino)malononitrile has been successfully developed providing an efficient strategy for the synthesis of substituted 1-tosyl-1H-pyrazoles.
