1776-09-6Relevant academic research and scientific papers
Conformationally constrained analogs of n-substituted piperazinylquinolones: Synthesis and antibacterial activity of n-(2,3-dihydro-4-hydroxyimino-4h-1-benzopyran-3-yl)-piperazinylquinolones
Emami, Saeed,Foroumadi, Alireza,Samadi, Nasrin,Faramarzi, Mohammad A.,Rajabalian, Saeed
, p. 405 - 411 (2009)
A series of novel quinolone agents bearing a particular bulky and conformationally constrained bicyclic substituent (2,3-dihydro-4-hydroxyimino- 4H-1-benzopyran-3-yl- moiety) on the piperazine ring of 7-piperazinyl quinolones (norfloxacin, enoxacin, ciprofloxacin, and levofloxacin) were synthesized and evaluated against a panel of Gram-positive and Gram-negative bacteria. Among these derivatives, ciprofloxacin counterpart 9c, highly inhibited the tested Gram-positive bacteria, superior to that of the reference drugs, and displayed antibacterial activity at non-cytotoxic concentrations.
Chemoselective Hydrosilylation of the α,β-Site Double Bond in α,β- And α,β,γ,δ-Unsaturated Ketones Catalyzed by Macrosteric Borane Promoted by Hexafluoro-2-propanol
Zhan, Xiao-Yu,Zhang, Hua,Dong, Yu,Yang, Jian,He, Shuai,Shi, Zhi-Chuan,Tang, Lei,Wang, Ji-Yu
, p. 6578 - 6592 (2020/07/17)
The B(C6F5)3-catalyzed chemoselective hydrosilylation of α,β- and α,β,γ,δ-unsaturated ketones into the corresponding non-symmetric ketones in mild reaction conditions is developed. Nearly 55 substrates including those bearing reducible functional groups such as alkynyl, alkenyl, cyano, and aromatic heterocycles are chemoselectively hydrosilylated in good to excellent yields. Isotope-labeling studies revealed that hexafluoro-2-propanol also served as a hydrogen source in the process.
1,2-oxazinopyran compound, and preparation method and application thereof
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Paragraph 0033-0035, (2020/08/30)
The invention provides a preparation method of a 1,2-oxazinopyran compound and a preparation method thereof. According to the preparation method for the compound, a pyrone compound is used as a substrate; a bromination reaction is conducted on the alpha-p
Enantioselective Total Syntheses of Pallambins A–D
Zhang, Xiwu,Cai, Xinxian,Huang, Bin,Guo, Lei,Gao, Zhongrun,Jia, Yanxing
supporting information, p. 13380 - 13384 (2019/08/16)
The first enantioselective total syntheses of (?)-pallambins A–D have been achieved in 15 or 16 steps from a known chiral cyclohexenone. Salient features of the syntheses include a palladium-catalyzed oxidative cyclization to assemble the [3.2.1]bicyclic moiety, an Eschenmoser–Claisen rearrangement/lactone formation sequence to construct the C ring, an intramolecular Wittig reaction to form the D ring, and individual transformations of pallambins C and D to generate pallambins A and B. The described synthesis avoids protecting-group manipulations through the design of highly chemo- and stereoselective transformations. During the course of this work, a palladium-catalyzed method for the dehydrobromination of α-bromoketones was developed, and the scope of this transformation was also investigated.
Highly Enantioselective Synthesis of Fused Tri- and Tetrasubstituted Aziridines: aza-Darzens Reaction of Cyclic Imines with α-Halogenated Ketones Catalyzed by Bifunctional Phosphonium Salt
Pan, Jianke,Wu, Jia-Hong,Zhang, Hongkui,Ren, Xiaoyu,Tan, Jian-Ping,Zhu, Lixiang,Zhang, Hong-Su,Jiang, Chunhui,Wang, Tianli
supporting information, p. 7425 - 7430 (2019/05/10)
The first enantioselective aza-Darzens reaction of cyclic imines with α-halogenated ketones was realized under mild reaction conditions by using amino-acid-derived bifunctional phosphonium salts as phase-transfer promoters. A variety of structurally dense tri- and tetrasubstituted aziridine derivatives, containing benzofused heterocycles as well as spiro-structures, were readily synthesized in high yields with excellent diastereo- and enantioselectivities (up to >20:1 d.r. and >99.9 % ee). The highly functionalized aziridine products could be easily transformed into different classes of biologically active compounds.
Synthesis of α,β-dibromo ketones by photolysis of α-bromo ketones with N-bromosuccinimide: Photoinduced β-bromination of α-bromo ketones
Moon, Da Yoon,An, Sejin,Park, Bong Ser
, (2019/10/28)
Irradiation of α-bromopropiophenones in the presence of NBS results in the formation of α,β-dibromopropiophenones, which can be viewed as β-bromination of α-bromopropiophenones. The reaction is believed to go through a series of reactions; photoinduced C–Br bond cleavage, elimination of HBr to give α,β-unsaturated ketone intermediates, and addition of Br2, which are formed by the reaction between HBr and NBS. From mechanistic studies of the reaction, we have also found a very convenient method for α-debromination of the α,β-dibromopropiophenones which is by simple irradiation of the dibromo ketones in acetone or 2-propanol without the use of any additives. Our results demonstrate that bromine can be added into or eliminated from the alpha, beta, or both positions to the carbonyl group by photochemical methods, which make synthetic options of bromine containing carbonyl compounds versatile.
MGLUR7 AGONIST COMPOUNDS FOR TREATING MGLUR7- REGULATED DISEASES, DISORDERS, OR CONDITIONS
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Paragraph 00178-00181, (2018/06/06)
The present invention provides compounds of formula (I) and pharmaceutically acceptable salts thereof wherein Z, R1, R2, R3, R4, R5 and R6 are as defined in the specification, a process for
Solvent free, light induced 1,2-bromine shift reaction of α-bromo ketones
An, Sejin,Moon, Da Yoon,Park, Bong Ser
, p. 6922 - 6928 (2018/10/24)
Photolysis of α-bromopropiophenones in acetonitrile results in formation of β-bromopropiophenones with good product selectivity, which can be coined as 1,2-Br shift reaction. The product selectivity increases when the reaction is done in neat or solid state, where only the 1,2-Br shift product is formed in some cases. The reaction is suggested to proceed by C–Br bond homolysis to give a radical pair, followed by disproportionation and conjugate addition of HBr to the α,β-unsaturated ketone intermediate. When the unsaturated intermediate is stabilized by an extra conjugation, the reaction stops at the stage, in which the unsaturated ketone becomes a major product. The synthetic method described in this research fits in a category of eco-friendly organic synthesis nicely since the reaction does not use volatile organic solvents and any other additives such as acid, base or metal catalysts, etc. Besides, the method fits into perfect atom economy, which does not give any side products. The synthetic method should find much advantage over other alternative methods to obtain β-bromo carbonyl compounds.
PPh3·HBr-DMSO: A Reagent System for Diverse Chemoselective Transformations
Mal, Kanchan,Kaur, Amanpreet,Haque, Fazle,Das, Indrajit
, p. 6400 - 6410 (2015/06/30)
The broad applicability of the hitherto unexplored reagent combination PPh3·HBr-DMSO is exemplified with multiple highly diverse one-step transformations to synthetically useful building blocks, such as flavones, 4H-thiochromen-4-ones, α-hydroxy ketones, 1,4-naphthoquinones (including vitamin K3), 2-bromo-3-substituted-1H-1-indenones, 2-methylthio-1H-1-indenones, 3-butyne-1,2-dione, and 4-pentene-2,3-diones. The simple and mild reaction conditions make the reagent superior in terms of yield and substrate scope in comparison with the existing alternatives.
Imidazolylchromanones containing non-benzylic oxime ethers: Synthesis and molecular modeling study of new azole antifungals selective against Cryptococcus gattii
Babazadeh-Qazijahani, Mojtaba,Badali, Hamid,Irannejad, Hamid,Afsarian, Mohammad Hosein,Emami, Saeed
, p. 264 - 273 (2014/03/21)
A series of imidazolylchromanone oximes containing phenoxyethyl ether moiety, as found in omoconazole, were synthesized and evaluated against yeasts (Candida albicans and Cryptococcus gattii) and filamentous fungi (Aspergillus fumigatus and Exophiala derm
