- Visible-Light-Mediated Strategies for the Preparation of Oxime Ethers Derived from O-H Insertions of Oximes into Aryldiazoacetates
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Two visible-light-mediated O-H insertion protocols involving oximes and aryldiazoacetates leading to different products depending on the solvent employed are reported. In DCM, direct O-H insertion takes place. In THF, there is the additional incorporation of the ring-opened form of this solvent into the structure of the product. These metal-free protocols are mild and tolerant to air and moisture. The preparation of an acaricide has been developed as an example of synthetic application.
- Duarte, Marcelo,Jurberg, Igor D.,Le?o, Luiz Paulo M. O.,Saito, Felipe A.,Stivanin, Mateus L.
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supporting information
p. 17528 - 17532
(2021/12/02)
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- Synthesis and SAR of new isoxazole-triazole bis-heterocyclic compounds as analogues of natural lignans with antiparasitic activity
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Despite the impressive scientific and technological advances of recent decades, no effective treatment is currently available for Chagas disease. Our research group has been studying the design and synthesis of analogues of natural lignans aiming to identify compounds with antiparasitic activity. This article reports the synthesis of 42 novel bis-heterocyclic derivatives and the structure-activity relationship study conducted based on results of biological assays against Trypanosoma cruzi amastigotes. Thirty-seven compounds were active, and eight of them had GI50 values lower than 100 μM (GI50 88.4–12.2 μM). A qualitative structure activity relationship study using three dimensional descriptors was carried out and showed a correlation between growth inhibitory potency and the presence of bulky hydrophobic groups located at rings A and D of the compounds. Compound 3-(3,4-dimethoxyphenyl)-5-((4-(4-pentylphenyl)-1H-1,2,3-triazol-1-yl)methyl)isoxazole (31) was the most active in the series (GI50 12.2 μM), showing, in vitro, low toxicity and potency similar to benznidazole (GI50 10.2 μM). These results suggest that this compound can be a promising scaffold for the design of new trypanocidal compounds.
- Zimmermann, Lara A.,de Moraes, Milene H.,da Rosa, Rafael,de Melo, Eduardo B.,Paula, Fávero R.,Schenkel, Eloir P.,Steindel, Mario,Bernardes, Lílian S.C.
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p. 4850 - 4862
(2018/09/11)
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- Novel chemoenzymatic oxidation of amines into oximes based on hydrolase-catalysed peracid formation
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The efficient transformation of benzylamines into the corresponding oximes has been described by means of a chemoenzymatic process. This strategy is based on a two-step sequence developed in one-pot at 30 °C and atmospheric pressure. First, the formation of a reactive peracid intermediate occurs by means of a lipase-catalysed perhydrolysis reaction, and then this peracid acts as a chemical oxidising agent of the amines. A total of nine ketoximes were isolated in high purity after a simple extraction protocol (90-98% isolated yield), while for the eleven synthesised aldoximes a further column chromatography purification was required (71-82% isolated yield). In all cases excellent selectivities were attained, offering a practical method for amine oxidation in short reaction times (1 hour). The environmental impact of the process was analysed and compared with a recently published alternative chemical synthesis, finding for this metric a good E-factor value.
- Méndez-Sánchez, Daniel,Lavandera, Iván,Gotor, Vicente,Gotor-Fernández, Vicente
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p. 3196 - 3201
(2017/04/21)
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- M-CPBA mediated metal free, rapid oxidation of aliphatic amines to oximes
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An efficient, rapid oxidation of various aliphatic amines to oximes using m-CPBA as an oxidant in ethyl acetate is described. High conversion (100%) with >90% oxime selectivity is achieved at room temperature under catalyst-free conditions. Mild reaction conditions along with an easy work up procedure offer lower byproduct formation and high selectivity for oximes in good yield and purity.
- Patil, Vilas V.,Gayakwad, Eknath M.,Shankarling, Ganapati S.
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p. 781 - 786
(2016/02/18)
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- Probing the antiamoebic and cytotoxicity potency of novel tetrazole and triazine derivatives
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A series of compounds bearing a Tetrazole and Triazine ring motif conjugated with a SO2NH function were synthesized and investigated for their antiamoebic potency. Cytotoxicity of the compounds was checked on human hepatocellular carcinoma cell line HepG2. Incorporation of Triazine ring in place of tetrazole resulted in a precipitous increase in the antiamoebic activity of the compounds. Antiamoebic activity of the investigated compounds was found to be position and substituent dependent. In vitro cytotoxicity results revealed noncytotoxic nature of all the tested compounds up to a concentration of 25 μM. Compound 5c and 5d were obtained as least cytotoxic (IC50 > 100 μM) and excellent Entamoeba histolytica inhibitors with IC50 values of 1.05 μM and 1.02 μM respectively.
- Wani, Mohmmad Younus,Bhat, Abdul Roouf,Azam, Amir,Choi, Inho,Athar, Fareeda
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experimental part
p. 313 - 320
(2012/03/27)
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- Novel terpene based 1,4,2-dioxazoles: Synthesis, characterization, molecular properties and screening against Entamoeba histolytica
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In present investigation a series of 20 dioxazole analogues (1-20) were synthesized, characterized and subjected to molecular properties prediction, anti-amoebic screening and cytotoxicity evaluation. Out of the twenty compounds viz. 3,5-substituted-1,4,2-dioxazoles, six compounds have shown IC50 values in the range (1.00-1.10 μM) lower than the standard drug metronidazole (IC50 = 1.45 μM). The toxicological studies of the active compounds on H9c2 rat cardiac myoblasts showed that all compounds were nontoxic. The pKa, and log P values have also been predicted. Compound 8 showed the most promising results based on anti-amoebic evaluation, cytotoxicity studies and physico-chemical properties prediction.
- Younus Wani, Mohmmad,Athar, Fareeda,Salauddin, Attar,Agarwal, Subhash Mohan,Azam, Amir,Choi, Inho,Roouf Bhat, Abdul
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experimental part
p. 4742 - 4752
(2011/11/04)
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- Studies on antiplatelet agents from natural safrole. II. Synthesis and pharmacological properties of novel functionalized oxime O-benzylether derivatives
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In an ongoing research program aiming at the synthesis and pharmacological evaluation of new possible prototype candidates exploring the molecular hybridation and bioisosterism principles for molecular designing, we describe in this paper the design and synthesis of a series of new functionalized oxime O-benzylethers (4a-b) and (14a-b) as antiplatelet agents based on the inhibition of arachidonic acid (AA) cascade enzymes. For the synthesis of these new bioactive derivatives we used safrole (5), a Brazilian abundant natural product, as starting material. The platelet anti-aggregating evaluation of these oxime O-benzylether compounds (4a-b) and (14a-b) in model induced by ADP, collagen and AA, has permitted to evidence an antithrombotic profile to these new derivatives, being the most active the derivative methyl [[3,4-methylenedioxyphenyl]methylene]amino]oxy]-4-methylenephenylacetic acid (14a). Copyright (C) 1999 Elsevier Science B.V.
- De A. Reis, Andre L.,Ormelli, Claudia B.,Miranda, Ana L.P.,Fraga, Carlos A.M.,Barreiro, Eliezer J.
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- A Fast Procedure for the Reduction of Azides and Nitro Compounds Based on the Reducing Ability of Sn(SR)3-Species
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Tin(II) complexes prepared by treatment of SnCl2 or Sn(SR)2 with appropriate amounts of RSH and Et3N appear to be the best reducing agents for azides (to amines) reported so far.Thes tin(II) complexes also reduce primary and secondary aliphatic nitro compounds to oximes, usually within minutes at r.t. or hours in cold, and tertiary aliphaic as well as aromatic nitro compounds to afford the corresponding hydroxylamines.In general, azides react more rapidly than nitro substituents, whereas carbonyl groups, sulphoxides, sulphones, nitriles, and esters are practically unreactive under the same conditions.Some mechanistic details of the reaction of Sn(SPh)3- with azides and nitro compounds have also been elucidated.
- Bartra, Marti,Romea, Pedro,Urpi, Felix,Vilarrasa, Jaume
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p. 587 - 594
(2007/10/02)
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