- Reduction of N-Nitrosaminoquinolinediones with LiAlH4 - An Easy Path to New Tricyclic Benzoxadiazocines
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3-Butylaminoquinolinediones (1) react with NaNO2 in AcOH to give the corresponding N-nitrosoderivatives (2). The analogous reactions of 4-hydroxy-3-butylaminoquinolinediones (5), prepared by the reduction of 1 with NaBH4, produce the corresponding nitrosamines (4). The reduction of both 2 and 4 with Zn under different conditions was non-productive, but the reduction of both compounds with LiAlH4 at the oxo and lactame groups yielded impure products, generating new tricyclic benzoxadiazocines (9) by a reaction with HNCO. All compounds were characterized by IR, 1H-, and 13C-NMR (in some cases, 15N-NMR also) spectroscopy and EI and/or ESI mass spectrometry. The X-ray structure of compound 9g was determined.
- Klásek, Antonín,Ly?ka, Antonín,K?emen, Filip,R??i?ka, Ale?,Rouchal, Michal
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Read Online
- Synthesis, Structure and Photophysical Properties of a New Class of Inherently Chiral Boron(III) Chelates—The tert-Leucine Complexes
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A new family of boron(III) chelates is introduced whereby molecular chirality, confirmed by circular dichroism, is imported during synthesis such that isolation of the diastereoisomers does not require separation procedures. The photophysical properties of two members of the family have been examined: the N,O,O-salicylaldehyde-based derivative shows pronounced intramolecular charge-transfer character in fluid solution and is weakly fluorescent, with a large Stokes shift. The corresponding 2-methylamino-benzaldehyde-derived N,N,O-chelate absorbs and fluoresces in the visible region with a much smaller Stokes shift. Orange fluorescence is also observed for this compound as a cast film. Temperature-dependence studies show that decay of the fluorescent state is weakly activated but emission is less than quantitative at 77 K. Quite rare for boron(III)-based chelates, this derivative undergoes intersystem crossing to form a meta-stable triplet-excited state. X-ray crystal structures are reported for both compounds, along with simulated ECD spectra.
- Algoazy, Nawaf,Knight, Julian G.,Waddell, Paul G.,Aerts, Roy,Herrebout, Wouter,Al-Sharif, Hatun H. T.,Karlsson, Joshua K. G.,Harriman, Anthony
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p. 5246 - 5258
(2021/02/26)
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- Preparation method and application of new theophylline boric acid compound
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The chemical formula of the compounds is shown in structural formulas (I) and (II). In-vitro antitumor activity screening results show that the compounds of the formula I and II have broad-spectrum anti-tumor activity and are used for human liver cancer (
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- Application of neostichophylline derivative in preparation of medicine for treating gastric cancer
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The invention belongs to the field of medicines, and particularly relates to an application of a neostichophylline derivative in preparation of a drug for treating gastric cancer. The invention finds that the neodeclarine derivative Z23 can inhibit the mi
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- Copper-Catalyzed (4+1) Cascade Annulation of Terminal Alkynes with 2-(Tosylmethyl)anilines: Synthesis of 2,3-Disubstituted Indoles
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A novel strategy based on Cu-catalyzed (4+1) cascade annulation of terminal alkynes as one-carbon synthons with 2-(tosylmethyl)anilines has been developed for the expeditious synthesis of 2,3-disubstituted indoles, in which in situ generations of aza-o-quinone methides and alkynyl-copper(I) species are involved. This annulation provides an effective method for the assembly of synthetically and structurally interesting 2,3-disubstituted indoles.
- Yan, Xu,Liu, Chun-Fang,An, Xian-Tao,Ge, Xiao-Min,Zhang, Qing,Pang, Lin-Han,Bao, Xu,Fan, Chun-An
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p. 8905 - 8909
(2021/11/24)
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- Substituent Effect Induces Emission Modulation of Stilbene Photoswitches by Spatial Tuning of the N/B Electronic Constraints
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We present a family of stilbene derivatives (1-4) ortho-functionalized with an electron donor and acceptor. Their emission was tuned by donor substitutions, dictating charge transfer dependent on the N···B spatial separation. The steric reduction of subst
- Chen, Pangkuan,Ji, Guangqian,Wang, Nan,Yin, Xiaodong
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supporting information
(2020/07/30)
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- Design, Synthesis, and Antifungal Evaluation of Neocryptolepine Derivatives against Phytopathogenic Fungi
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Neocryptolepine is an alkaloid isolated from traditional African herbal medicine Cryptolepis sanguinolenta, and its broad spectrum of biological activities has been illuminated in past decades. In this study, neocryptolepine and its derivatives (1-49) were designed and synthesized from economical and readily available starting materials. Their structures were confirmed by proton nuclear magnetic resonance, carbon nuclear magnetic resonance, and mass spectrometry. The synthesized compounds were screened for their antifungal profile against six agriculturally important fungi Rhizoctonia solani, Botrytis cinerea (B. cinerea), Fusarium graminearum, Mycosphaerella melonis, Sclerotinia sclerotiorum, and Magnaporthe oryzae. The results of in vitro assay revealed that compounds 5, 21, 24, 35, 40, 45, and 47 presented remarkable antifungal activity against the fungi tested with EC50 values lower than 1 μg/mL. Significantly, compound 24 displayed the most effective inhibitory potency against B. cinerea (EC50 = 0.07 μg/mL), and the data from in vivo experiments revealed that compound 24 demonstrated comparable protective activity with the positive control boscalid. Preliminary mechanism studies indicated that compound 24 showed impressive spore germination inhibitory effectiveness and lower cytotoxicity than azoxystrobin, imparted on normal function of the cell membrane and cell wall, and arrested the normal function of the nucleus. Besides the excellent inhibitory activity against agriculturally important phytopathogenic fungi tested, the designed assemblage possesses several benefits with a high profile of variation in synthesized molecules, the ease of synthesis, and good cost-effectiveness of commercially available synthetic reagents, all of these have highlighted the potential worth of compound 24 as a new and highly efficient agricultural fungicide.
- Gao, Jian-Mei,Lawoe, Raymond Kobla,Liu, Ying-Qian,Shang, Xiao-Fei,Sun, Yu,Yang, Cheng-Jie,Yin, Xiao-Dan,Zhao, Zhong-Min,Zhou, Rui,Zhu, Jia-Kai
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p. 2306 - 2315
(2020/03/10)
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- Chiral Phosphoric-Acid-Catalyzed Cascade Prins Cyclization
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Asymmetric Prins cyclization of in situ generated quinone methides and o-aminobenzaldehyde has been developed with chiral phosphoric acid as an efficient catalyst. This unconventional method provides a facile access to diverse functionalized trans-fused pyrano-/furo-tetrahydroquinoline derivatives in excellent yield and with excellent diastereo- and enantioselectivities (up to 99% yield and 99% ee). Mechanistic studies suggested that the three adjacent tertiary stereocenters were constructed through the sequential formation of C-O, C-C, and C-N bonds.
- Sun, Huai-Ri,Zhao, Qingyang,Yang, Hui,Yang, Sen,Gou, Bo-Bo,Chen, Jie,Zhou, Ling
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supporting information
p. 7143 - 7148
(2019/09/07)
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- Efficient Direct Synthesis of Aziridine-Containing Chiral Tridentate Ligands by the Iminium-Mediated Self-Ring Opening Reaction of Enantiopure Aziridines and Salicylaldehydes
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An efficient method for the direct synthesis of aziridine-containing chiral tridentate ligands was developed from enantiopure aziridines and salicylaldehydes. The method achieved the regiospecific cleavage of more substituted C?N bonds of aziridines through an iminium-mediated self-ring opening reaction of aziridines with up to 95% yield and complete inversion of configuration. The (S)-2-alkylaziridine-derived tridentate ligands displayed excellent activity and stereoselectivity in the zinc trifluoromethanesulfonate-catalyzed asymmetric aldol reactions of acetone and aromatic aldehydes. (Figure presented.).
- Chen, Xingpeng,Lin, Chao,Du, Hongguang,Xu, Jiaxi
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p. 1647 - 1661
(2019/02/27)
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- Synthesis of Tetrahydropyrazolo[4',3':5,6]pyrano[3,4- c ]quinolones by Domino Knoevenagel/Hetero Diels-Alder Reactions
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An efficient Lewis acid mediated domino Knoevenagel/hetero Diels-Alder (DKHDA) reaction of pyrazolone derivatives with N -acrylated anthranilic aldehydes was developed, which afforded functionalized tetracyclic tetrahydropyrazolo[4',3':5,6]pyrano[3,4- c ]quinolones. The products were formed in good yields and with excellent regio- and stereoselectivity in favor of the cis-configured isomer.
- Jafari, Behzad,Khodabakhshi, Mohammad Reza,Kiamehr, Mostafa,Langer, Peter,Mohammadkhani, Leyla
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p. 1782 - 1786
(2019/09/09)
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- An Efficient Metal-Free Method for the Denitrosation of Aryl N-Nitrosamines at Room Temperature
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A simple and practical method for the denitrosation of aryl N-nitrosamines to secondary amines is reported under metal-free conditions using iodine and triethylsilane. Several reduction-susceptible functional groups such as alkene, alkyne, nitrile, nitro, aldehyde, ketone and ester were found to be very stable during the denitrosation, which is remarkable. Broad substrate scope, room temperature reactions and excellent yields are the additional features of the current methodology. (Figure presented.).
- Chaudhary, Priyanka,Korde, Rishi,Gupta, Surabhi,Sureshbabu, Popuri,Sabiah, Shahulhameed,Kandasamy, Jeyakumar
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supporting information
p. 556 - 561
(2017/11/13)
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- Aerobic C–C Bond Cleavage of Indoles by Visible-Light Photoredox Catalysis with Ru(bpy)32+
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Photoredox catalysis with Ru(bpy)32+ (2,2′-bipyridine) has been used to enable the activation of oxygen in the aerobic C–C cleavage/oxygenation reaction of indoles. A number of indole substrates that contain various functional groups were successfully employed in the reaction to give a wide range of ortho-aminobenzaldehyde derivatives. These products can then be used as versatile building blocks for further synthetic modifications. Mechanistic studies suggest that the reaction proceeds through a radical pathway.
- Ji, Xiaochen,Li, Dongdong,Wang, Zhongzhen,Tan, Muyun,Huang, Huawen,Deng, Guo-Jun
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p. 6652 - 6659
(2017/12/15)
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- Visible Light Photocatalytic Aerobic Oxygenation of Indoles and pH as a Chemoselective Switch
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An efficient chemodivergent strategy for visible light photocatalysis is developed. In the presence of a dicyanopyrazine-derived chromophore (DPZ) photocatalyst, aerobic photooxygenation of indoles could produce either isatins or formylformanilides in satisfactory yields by judiciously selecting inorganic salts or modulating the reaction pH. The current chemodivergent method is also effective with 2-substituted indoles, opening straightforward synthetic routes to valuable 2,2-disubstituted 3-oxindoles, formylformanilide derivatives, and benzoxazinones. Mechanistic investigations involving cyclic voltammetry studies further confirm that reaction pH influences the electrochemical properties of DPZ, thus affecting the oxidative pathway by which indoles are being transformed.
- Zhang, Chenhao,Li, Sanliang,Bure?, Filip,Lee, Richmond,Ye, Xinyi,Jiang, Zhiyong
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p. 6853 - 6860
(2016/10/18)
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- Method for preparing N-(2-formyl phenyl) N-substituted formamide derivatives by means of visible light catalysis
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The invention relates to a method for preparing N-(2-formyl phenyl) N-substituted formamide derivatives by means of visible light catalysis, belonging to the technical field of visible light catalytic synthesis. A synthetic route is described in the description, wherein the structural formula of DPZ is described in the description, R is -H, -OMe, -F or -Cl, and R is -Me, -Bn or -Ph; the synthetic process comprises the steps of dissolving a compound 1, the DPZ, K3PO4 and TEMPO into a mixed solvent of CH3CN and water, carrying out a reaction at the constant temperature of 25 DEG C under a blue lamp light source in an oxygen atmosphere, tracking and monitoring by using thin layer chromatography (TLC), and after the reaction is finished, carrying out column chromatographic separation to obtain a compound 2. The method can be used for efficiently preparing the N-(2-formyl phenyl) N-substituted formamide derivatives, and has the advantages of being environmental-friendly, high in reaction efficiency, simple in aftertreatment and low in cost.
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Paragraph 0050; 0051
(2018/02/04)
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- Visible-light-mediated reaction: Synthesis of quinazolinones from 1,2-dihydroquinazoline 3-oxides
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1-Methyl-2-phenylquinazolin-4(1H)-ones were synthesized in good yield by exposing 1,4-dimethyl-2-phenyl-1,2-dihydroquinazoline 3-oxides or 1-methyl-2-phenyl-1,2-dihydroquinazoline 3-oxides to visible light in acetonitrile in the absence of any external ph
- Wu, Chun-Ku,Yang, Ding-Yah
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p. 65988 - 65994
(2016/07/26)
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- Expedient synthesis of novel coumarin-based sulfonamides
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The synthesis of novel coumarin-based sulfonamides was accomplished in good yields via InCl3-catalyzed three-component condensation of N-(2-formylphenyl)-N-methylbenzenesulfonamides, 4-hydroxycoumarin and cyclic secondary amines in toluene.
- Ghandi, Mehdi,Babazadeh, Elham
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p. 379 - 387
(2015/02/05)
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- Diastereoselective Synthesis of Novel Pyrrolidine or Pyrrolizine-Fused Benzo-δ-sultams via 1,3-Dipolar Cycloadditions
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The synthesis of novel pyrrolidine or pyrrolizine-fused benzosultams is described. A number of (E)-N-(2-formylphenyl)-N-alkyl-2-phenylethenesulfonamides derivatives were synthesized and subjected to intramolecular [3+2] cycloaddition with azomethine ylides derived in situ from the reaction with sarcosine, phenylglycine, and L-proline.
- Ghandi, Mehdi,Kia, Maryam Asle,Sadeghzadegh, Masoud,Bozcheloei, Abolfazl Hasani,Kubicki, Maciej
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p. 1646 - 1653
(2015/02/19)
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- 2-aminobenzaldehydes as versatile substrates for rhodium-catalyzed alkyne hydroacylation: Application to dihydroquinolone synthesis
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Amine for it! A cationic rhodium catalyst, which was assembled insitu from commercial components, promoted the reaction of a range of simple 2-aminobenzaldehydes with terminal and internal alkynes in a series of intermolecular hydroacylation reactions. The products of this reaction, amino-substituted enones, were efficiently converted into the corresponding dihydro-4-quinolones.
- Castaing, Matthias,Wason, Sacha L.,Estepa, Beatriz,Hooper, Joel F.,Willis, Michael C.
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supporting information
p. 13280 - 13283
(2014/01/06)
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- Synthesis of novel tetra- and pentacyclic benzosultam scaffolds via domino Knoevenagel hetero-Diels-Alder reactions in water
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An efficient catalyst-free and diastereoselective synthesis of novel dihydropyrano[2,3-d]pyrimidine and dihydropyrano[3,2-c]chromen-annulated benzosultams is described. A number of (E)-N-(2-formylphenyl)-N-methyl-2- phenylethenesulfonamides were synthesized and underwent a one-pot domino Knoevenagel hetero-Diels-Alder reaction, respectively, with N,N- dimethylbarbituric acid and 4-hydroxycoumarin in water, giving the desired products, in moderate to excellent yields.
- Ghandi, Mehdi,Sheibani, Shahab,Sadeghzadeh, Masoud,Daha, Fariba Johari,Kubicki, MacIej
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p. 1057 - 1065
(2013/11/06)
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- Ethylenediamine diacetate (EDDA)-catalyzed one-pot synthesis of tetrahydroquinolines by domino Knoevenagel/hetero Diels-Alder reactions from 1,3-dicarbonyls
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This paper describes new and efficient synthetic approaches for biologically interesting tetrahydroquinoline analogues. The key strategies involve the ethylenediamine diacetate-catalyzed cyclization of 1,3-dicarbonyls to aminobenzaldehydes through domino Knoevenagel/hetero Diels-Alder reactions. These reactions provide a rapid route for the synthesis of novel polycycles with the tetrahydroquinoline moiety.
- Lee, Yong Rok,Hung, Thai Viet
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p. 7338 - 7346
(2008/12/21)
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- Bridgehead nitrogen heterocycles which contain the quinazoline moiety - Synthesis and cycloaddition of 1,2-dihydroquinazoline 3-oxides
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A novel synthesis of 1,2-disubstituted 1,2-dihydroquinazoline 3-oxides 8 and the first ever examples of 1,3-dipolar trapping of these nitrones to homonuclear dipolarophiles is described. The new dipoles 8 reacted with N-methyl maleimide, generating diastereomeric adducts 14-16. In the reaction between 8 and dimethyl acetylenedicarboxylate, primary cycloadducts 17 and/or stable rearrangement products, azomethine ylides 18, are formed depending on the substitution pattern of the dipole. The structure of 18c is unambiguously assigned by X-ray crystallographic analysis. An X-ray crystal structure determination is also presented for the cyclopropylisoxazoloquinazoline 22 formed by a [3 + 2] addition of 8a to 21, the dimethyl acetylenedicarboxylate tetramer. The Royal Society of Chemistry 2005.
- Heaney, Frances,McCarthy, Tomas,Mahon, Mary,McKee
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p. 4351 - 4361
(2007/10/03)
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- A SYNTHETIC EQUIVALENT FOR ORTHO-LITHIO-N-METHYLANILINE
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o-Bromo-N-methyl-N-n-propoxyaniline undergoes halogen-metal exchange with butyllithium and the resulting lithio species reacts cleanly with a variety of electrophiles.The N-O bond of these products can be reduced with Raney nickel to afford ortho-substituted-N-methylanilines.
- Sisko, Joseph,Weinreb, Steven M.
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p. 1035 - 1042
(2007/10/02)
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- Nickel-Catalyzed Transformations of 2,1-Benzisoxazoles with Organozinc Reagents
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A novel transformation of 2,1-benzisoxazoles (anthranils) involving nitrogen-oxygen bond rupture with concomitant nitrogen-carbon bond formation by reaction with aryl-, methyl, or 2-thienylzinc chlorides in the presence of nickel catalyst is described.The products of the reaction are o-(substituted-amino)benzaldehydes and benzophenones, precursors of a series of heterocyclic derivatives, including acridines, quinolones, and the novel 7-chloro-1,3-dihydro-1,5-diphenyl-2H-1,4-benzodiazepin-2-one (21)
- Baum, Jonathan S.,Condon, Michael E.,Shook, David A.
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p. 2983 - 2988
(2007/10/02)
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- Nucleophilic attack on 2,1-benzisothiazolium salts
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2,1-benzisothiazolium salts react with several stabilized carbanions to give products that are derived by attack at the carbon atom of the heterocyclic ring.
- McKinnon, David M.,Duncan, K. Ann,Millar, Lesley M.
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p. 440 - 444
(2007/10/02)
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