18184-75-3Relevant articles and documents
Electroselective and Controlled Reduction of Cyclic Imides to Hydroxylactams and Lactams
Bai, Ya,Shi, Lingling,Zheng, Lianyou,Ning, Shulin,Che, Xin,Zhang, Zhuoqi,Xiang, Jinbao
supporting information, p. 2298 - 2302 (2021/04/05)
An efficient and practical electrochemical method for selective reduction of cyclic imides has been developed using a simple undivided cell with carbon electrodes at room temperature. The reaction provides a useful strategy for the rapid synthesis of hydroxylactams and lactams in a controllable manner, which is tuned by electric current and reaction time, and exhibits broad substrate scope and high functional group tolerance even to reduction-sensitive moieties. Initial mechanistic studies suggest that the approach heavily relies on the utilization of amines (e.g., i-Pr2NH), which are able to generate α-aminoalkyl radicals. This protocol provides an efficient route for the cleavage of C-O bonds under mild conditions with high chemoselectivity.
Catalytic Transfer Hydrodebenzylation with Low Palladium Loading
Yakukhnov, Sergey A.,Ananikov, Valentine P.
supporting information, p. 4781 - 4789 (2019/09/16)
A highly-efficient catalytic system for hydrodebenzylation reaction is described. The cleavage of O-benzyl and N-benzyl protecting groups was performed using an uncommonly low palladium loading (0.02–0.3 mol%; TON up to 5000) in a relatively short reaction time. The approach was used for a variety of substrates including pharmaceutically important precursors, and gram-scale deprotection reaction was shown. Transfer conditions together with easy-to-make Pd/C catalyst are the key features of this debenzylation scheme. (Figure presented.).
Alkoxide-Catalyzed Hydrosilylation of Cyclic Imides to Isoquinolines via Tandem Reduction and Rearrangement
Wu, Xiaoyu,Ding, Guangni,Yang, Liqun,Lu, Wenkui,Li, Wanfang,Zhang, Zhaoguo,Xie, Xiaomin
supporting information, p. 5610 - 5613 (2018/09/12)
An alkoxide-catalyzed hydrosilylation of cyclic imides to isoquinolines was realized via tandem reduction and rearrangement. Using TMSOK as the catalyst and (EtO)2MeSiH as the reductant, a series of cyclic imides containing different functional groups were reduced to the corresponding 3-aryl isoquinolines in moderate to good yields. The scenario of the reaction pathway was supposed to involve the reduction of imides to ω-hydroxylactams, which underwent rearrangement in the presence of a base catalyst, and then the carbonyl reduction, followed by siloxy elimination.
Discovery of novel substituted octahydropyrrolo[3,4-c]pyrroles as dual orexin receptor antagonists for insomnia treatment
Wu, Songliang,Sun, Yu,Hu, Yi,Zhang, Hongmei,Hou, Lijuan,Liu, Xing,Li, Yufeng,He, Haiying,Luo, Zhi,Chen, Yuan,Wang, Yuhe,Shi, Weihua,Shen, Liang,Cao, Changqing,Liang, Wei,Xu, Qing,Lv, Qiang,Lan, Jiong,Li, Jian,Chen, Shuhui
supporting information, p. 1458 - 1462 (2017/03/08)
A series of octahydropyrrolo[3,4-c]pyrroles were synthesized and evaluated by orexin 1 and 2 receptor (OX1 & 2R) antagonists assays. Compound 14l with potent OXR antagonist activity and suitable pharmacokinetic behavior was chosen to be investigated in an EEG study, which demonstrated effects of sleep promotion comparable to Suvorexant. Furthermore, the di-fluro substituted analogs exhibited reduced hERG inhibition while maintaining moderate potency.
Efficient synthesis of (S,S)-2,8-diazabicyclo[4.3.0]nonane
Chen, Shipeng,Liu, Dongqi,Si, Leilei,Chen, Ligong,Yan, Xilong
supporting information, p. 238 - 244 (2017/01/22)
An efficient synthetic route for moxifloxacin chiral intermediate via five steps was established. First, dehydration, N-acylation, and cyclization were combined in one pot to meet the industrial requirement. Then relatively low hydrogen pressure was employed in the catalytic hydrogenation reaction with high yield. Isopropanol/water system was used in resolution, which guaranteed high yield and perfect optical purity. The racemic process conducted by manganese dioxide and Pd/C successfully converted the undesired enantiomer into the racemate and hence the total yield increased remarkably. Furthermore, mild hydrogen transfer catalytic hydrogenation method was utilized in debenzylation process instead of high-pressure hydrogenation. Total yield of 39.0% was achieved, which was much higher than that of 29.0% in literature.
(S, S) - 2,8-diazabicyclo [4.3.0] nonane preparation method
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Paragraph 0069; 0070, (2017/02/09)
The invention relates to a novel preparation method of (S,S)-2,8-diazabicyclo[4.3.0]. The method comprises the steps that: 2,3-pyridine dicarboxylic acid derivative and amide are subjected to condensation, such that 2,3-pyridine dicarboximide is formed; 2,3-pyridine dicarboximide is subjected to protection and hydrogenation reduction, such that 8-substituted-7,9-dioxo-2,8-diazabicyclo[4.3.0]nonane is produced; the product is reduced in a borohydride reduction system, such that 8-substituted-2,8-diazabicyclo[4.3.0]nonane is obtained; the product is subjected to optical-active organic acid resolution, such that 8-site protection group is removed, and the final product is obtained. Or, 2,3-pyridine dicarboximide is directly subjected to hydrogenation reduction, such that 7,9-dioxo-2,8-diazabicyclo[4.3.0]nonane is produced; the product is directly reduced in a borohydride reduction system, such that 2,8-diazabicyclo[4.3.0]nonane is produced; the 2,8-diazabicyclo[4.3.0]nonane is subjected to optical-active organic acid resolution, such that the final product is directly obtained. The method provided by the invention is advantaged in simple reaction route. The raw materials are cheap and easy to obtain. The reaction conditions are mild and easy to control. The method is suitable for industrialized productions.
Synthesis method for moxifloxacin side chain
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Paragraph 0024; 0025; 0040, (2016/10/10)
The invention discloses a synthesis method for a moxifloxacin side chain.With 2,3-dipicolinic acid being a raw material, cyclization, catalytic hydrogenation, resolution and racemization are performed, and then chemical reduction and debenzylation are performed to obtain moxifloxacin side chain.Resolution, racemization and chemical reduction are performed in sequence, sodium borohydride is used for replacing high-risk lithium aluminum hydride to synthesize the moxifloxacin side chain, and the synthesis method has the advantages that industrial waste materials are reduced, the production cost is lowered, and productivity is increased.
Zinc-catalyzed selective reduction of cyclic imides with hydrosilanes: Synthesis of ω-hydroxylactams
Ding, Guangni,Lu, Bin,Li, Yuyuan,Wan, Jun,Zhang, Zhaoguo,Xie, Xiaomin
supporting information, p. 1013 - 1021 (2015/03/30)
Cyclic imides were selectively reduced to the corresponding ω-hydroxylactams in high yields with (EtO)3SiH (triethoxysilane) or PMHS (polymethylhydrosiloxane) under catalysis of zinc diacetate dehydrate [Zn(OAc)2 2H2O] (10%) and tetramethylethylenediamine (TMEDA) (10%). This catalytic protocol showed good functional group tolerance as well as excellent regioselectivity for unsymmetrical imides bearing coordinating groups adjacent to the carbonyl.
Design, Synthesis, Antifungal Activities and SARs of (R)-2-Aryl-4,5-dihydrothiazole-4-carboxylic Acid Derivatives
Liu, Jingbo,Li, Yuxin,Chen, Youwei,Hua, Xuewen,Wan, Yingying,Wei, Wei,Song, Haibin,Yu, Shujing,Zhang, Xiao,Li, Zhengming
, p. 1269 - 1275 (2015/11/27)
Based on the structure of natural product 2-aryl-4,5-dihydrothiazole-4-carboxylic acid, a series of novel (R)-2-aryl-4,5-dihydrothiazole-4-carboxylic acid derivatives were designed and synthesized. Their structures were characterized by 1H NMR, 13C NMR and HRMS. The single crystal structure of compound 9b was determined by X-ray diffraction analysis. The antifungal activities were evaluated for the first time. The bioassay results indicated that most compounds exhibited moderate to good antifungal activities. The antifungal activities of compound 13a (against Cercospora arachidicola Hori), 13d (against Alternaria solani), and 16e (against Cercospora arachidicola Hori) were 61.9%, 67.3% and 61.9%, respectively, which are higher than those of the commercial fungicides chlorothalonil and carbendazim. Moreover, compound 13d exhibited excellent antifungal activities against 7 kinds of the fungi tested (66.7%, 77.3%, 63.0%, 87.9%, 70.0%, 70.0% and 80.0% at 50 μg?mL). Therefore, 13d can be used as a new lead structure for the development of antifungal agents.
Efficient conversion of acids and esters to amides and transamidation of primary amides using OSU-6
Nammalwar, Baskar,Muddala, Nagendra Prasad,Watts, Field M.,Bunce, Richard A.
, p. 9101 - 9111 (2015/11/09)
OSU-6, an MCM-41 type hexagonal mesoporous silica with strong Bronsted acid properties, has been used to promote the high-yield conversion of carboxylic acids and esters to carboxamides as well as transamidations of primary amides in a one-pot solventless approach. A metal-free heterogeneous catalyst that promotes all of these processes has not been previously reported. OSU-6 enables these transformations to proceed in shorter times and at lower temperatures for a broad range of substrates. An added benefit is that the catalyst can be recycled and reused multiple times without significant loss of activity.
