3717-22-4Relevant articles and documents
On the mixed oxides-supported niobium catalyst towards benzylamine oxidation
Granato, álisson Silva,de Carvalho, Gustavo S. Gon?alves,Fonseca, Carla G.,Adrio, Javier,Leit?o, Alexandre A.,Amarante, Giovanni Wilson
, p. 118 - 125 (2020/09/11)
A series of mixed oxides-supported niobium-based catalysts has been synthesized and applied towards oxidation reactions of benzylamine derivatives. Under the optimized reaction conditions, the selectivity to oxime enhanced, leading to the main product with up to 72 %. Moreover, even α-substituted benzylamines were well tolerated and led to oximes in good isolated yields. It is important to mention; four equivalents of the harmless and inexpensive hydrogen peroxide were employed as oxidizing agent. Mechanism hypothesis suggested that the reaction proceed to selective benzylamine oxidation into nitroso intermediate, following by formation of the corresponding oxime tautomer mediated by an unstable water produced by NbOx supported catalyst. This consists the first mixed oxides-supported niobium-based catalyst for selective oxidation of benzylamines to oximes.
Enolate-Based Regioselective Anti-Beckmann C-C Bond Cleavage of Ketones
Jahn, Ullrich,Ma?ek, Tomá?
, p. 11608 - 11632 (2021/09/02)
The Baeyer-Villiger or Beckmann rearrangements are established methods for the cleavage of ketone derivatives under acidic conditions, proceeding for unsymmetrical precursors selectively at the more substituted site. However, the fragmentation regioselectivity cannot be switched and fragmentation at the less-substituted terminus is so far not possible. We report here that the reaction of ketone enolates with commercial alkyl nitrites provides a direct and regioselective way of fragmenting ketones into esters and oximes or ω-hydroxyimino esters, respectively. A comprehensive study of the scope of this reaction with respect to ketone classes and alkyl nitrites is presented. Control over the site of cleavage is gained through regioselective enolate formation by various bases. Oxidation of kinetic enolates of unsymmetrical ketones leads to the otherwise unavailable "anti-Beckmann"cleavage at the less-substituted side chain, while cleavage of thermodynamic enolates of the same ketones represents an alternative to the Baeyer-Villiger oxidation or the Beckmann rearrangement under basic conditions. The method is suited for the transformation of natural products and enables access to orthogonally reactive dicarbonyl compounds.
Visible-Light-Mediated Strategies for the Preparation of Oxime Ethers Derived from O-H Insertions of Oximes into Aryldiazoacetates
Duarte, Marcelo,Jurberg, Igor D.,Le?o, Luiz Paulo M. O.,Saito, Felipe A.,Stivanin, Mateus L.
supporting information, p. 17528 - 17532 (2021/12/02)
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.
1,3-dipolar cycloaddition reactions of the compound obtaining from cyclopentadiene-PTAD and biological activities of adducts formed selectively
Bayrak, Cetin,Menzek, Abdullah,Taskin-Tok, Tugba,Taslimi, Parham,Yavari, Mirali Akbar
, (2022/01/04)
After known adduct (4) was synthesized by cycloaddition reaction of cyclopentadiene with 4-phenyl-1,2,4-triazoline-3,5-dione, seven new isoxazoline derivatives were synthesized from reactions of 4 with corresponding oximes prepared from benzaldehyde derivatives in the existence of the aqueous NaOCl in CH2Cl2 at 0°C—RT via nitrile oxides. Four new pyrazoline derivatives were also synthesized from reactions of 4 with corresponding prepared reagents via nitrile imines. Selectively, each of all isoxazole and pyrazoline derivatives was synthesized by 1,3-dipolar cycloaddition reactions of compound 4 with the corresponding reagents. Based on the results of their biological activity analyses, Ki values for acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and alpha-glucosidase (α-Gly) enzymes were obtained in this range 32.15 ± 5.73–107.44 ± 19.52 22.57 ± 4.30–186.07 ± 23.51, and 69.08 ± 8.54–528.07 ± 38.46 nM, respectively. Besides that, these compounds were subjected to molecular docking to describe the interaction against AChE, BChE, and α-Gly enzymes in which important interactions were visualized and evaluated with residues of the binding region in each target enzyme.
Visible-light mediated stereospecific C(sp2)-H difluoroalkylation of (Z)-aldoximes
Chen, Hua,Deng, Hongmei,Gong, Haiying,Hao, Jian,Li, Mingjie,Peng, Yi,Wan, Wen,Wang, Qian,Zhang, Yifang
supporting information, p. 7867 - 7874 (2021/09/28)
A visible light mediated stereospecific C(sp2)-H difluoroalkylation of (Z)-aldoximes to (E)-difluoroalkylated ketoximes has been described. In this reaction, (hetero)-aromatic and aliphatic difluoroalkylated ketoximes could be obtained with the retention of the configuration of the starting aldoximes. A preliminary mechanism study showed that a difluoromethyl radicalviaan SET pathway was involved.
Dioxido-vanadium(V) complex catalyzed oxidation of alcohols and tandem synthesis of oximes: a simple catalytic protocol for C–N bond formation
Kurbah, Sunshine Dominic
, p. 905 - 918 (2021/02/03)
We report the synthesis of a vanadium(V) complex characterized by FT-IR and 1H NMR spectroscopy. The structure of the complex was established by single crystal X-ray crystallography. We also carried out the catalytic oxidation of benzyl alcohol, hetero-aryl alcohols and propargylic alcohols. Tandem synthesis of oximes from alcohols were also carried out using our vanadium(V) complex. The newly synthesized complex acts as a catalyst for oxidation reactions and tandem synthesis of oxime from alcohols.
Poly(N-vinylimidazole): A biocompatible and biodegradable functional polymer, metal-free, and highly recyclable heterogeneous catalyst for the mechanochemical synthesis of oximes
Fahim, Hoda,Ghaffari Khaligh, Nader,Gorjian, Hayedeh
, p. 2007 - 2012 (2022/01/08)
The catalytic activity of poly(N-vinylimidazole), a biocompatible and biodegradable synthetic functional polymer, was investigated for the synthesis of oximes as an efficient, halogen-free, and reusable heterogeneous catalyst. The corresponding oximes were afforded in high to excellent yields at room temperature and in short times using the planetary ball mill technique. Some merits, such as the short reaction times and good yields for poorly active carbonyl compounds, and avoiding toxic, expensive, metal-containing catalysts, and hazardous and flammable solvents, can be mentioned for the current catalytic synthesis of the oximes. Furthermore, the heterogeneous organocatalyst could be easily separated after the reaction, and the regenerated catalyst was reused several times with no significant loss of its catalytic activity.
Design, synthesis and biological evaluation of novel indanone containing spiroisoxazoline derivatives with selective COX-2 inhibition as anticancer agents
Abolhasani, Hoda,Zarghi, Afshin,Komeili Movahhed, Tahereh,Abolhasani, Ahmad,Daraei, Bahram,Dastmalchi, Siavoush
, (2021/01/25)
Objective: A new family of 3′-(Mono, di or tri-substituted phenyl)-4′-(4-(methylsulfonyl) phenyl) spiroisoxazoline derivatives containing indanone spirobridge was designed, synthesized, and evaluated for their selective COX-2 inhibitory potency and cytotoxicity on different cell lines. Methods: A synthetic reaction based on 1,3-dipolar cycloaddition mechanism was applied for the regiospecific formation of various spiroisoxazolines. The activity of the newly synthesized compounds was determined using in vitro cyclooxygenase inhibition assay. The toxicity of the compounds was evaluated by MTT assay. In addition, induction of apoptosis, and expression levels of Bax, Bcl-2 and caspase-3 mRNA in MCF-7 cells were evaluated following exposure to compound 9f. The docking calculations and molecular dynamics simulation were performed to study the most probable modes of interactions of compound 9f upon binding to COX-2 enzyme. Results: The docking results showed that the synthesized compounds were able to form hydrogen bonds with COX-2 involving methyl sulfonyl, spiroisoxazoline, meta-methoxy and fluoro functional groups. Spiroisoxazoline derivatives containing methoxy group at the C-3′ phenyl ring meta position (9f and 9g) showed superior selectivity with higher potency of inhibiting COX-2 enzyme. Furthermore, compound 9f, which possesses 3,4-dimethoxyphenyl on C-3′ carbon atom of isoxazoline ring, exhibited the highest COX-2 inhibitory activity, and also displayed the most potent cytotoxicity on MCF-7 cells with an IC50 value of 0.03 ± 0.01 μM, comparable with that of doxorubicin (IC50 of 0.062 ± 0.012 μM). The results indicated that compound 9f could promote apoptosis. Also, compared to the control group, the mRNA expression of Bax and caspase-3 significantly increased, while that of Bcl-2 significantly decreased upon exposure to compound 9f which may propose the activation of mitochondrial-associated pathway as the mechanism of observed apoptosis. Conclusion: In vitro biological evaluations accompanied with in silico studies revealed that indanone tricyclic spiroisoxazoline derivatives are good candidates for the development of new anti-inflammatory and anticancer (colorectal and breast) agents.
Identification of morpholine based hydroxylamine analogues: Selective inhibitors of MARK4/Par-1d causing cancer cell death through apoptosis
Avecilla, Fernando,Azam, Amir,Gaur, Aysha,Hassan, Md. Imtaiyaz,Khan, Nashrah Sharif,Khan, Parvez,Peerzada, Mudasir Nabi
supporting information, p. 16626 - 16637 (2020/10/14)
Microtubule affinity-regulating kinase 4 (MARK4) is a serine/threonine kinase involved in the phosphorylation of MAP proteins that regulates microtubule dynamics and abets tumor progression by participating in oncogenic signaling pathways. It is overexpressed in multiple human malignancies and no drug is available for this potential therapeutic target at present. Therefore, using the structure based drug design strategy, a library of hydroxylamine derivatives of morpholine were designed and synthesized as small molecule inhibitors of MARK4. Compound 32 having the CF3 group at the ortho position of the phenyl ring tethered with the >CNOH core and the hinge binder morpholine component was found to be a potent and selective inhibitor of MARK4 over thirty other serine-threonine kinases. Study of cell viability and compound induced morphological changes in MCF-7 cancer cells discovered that molecule 32 caused death of cancerous cells through the mechanism of apoptosis. Compound 32 may be transported and delivered to the target site through the blood stream, and has promising antioxidant potential. Such bio-active molecules could serve as optimized lead candidates in drug discovery for cancer treatment through MARK4 inhibition.
Annulation of Oxime-Ether Tethered Donor–Acceptor Cyclopropanes
Irwin, Lauren C.,Allen, Meredith A.,Vriesen, Matthew R.,Kerr, Michael A.
supporting information, p. 171 - 175 (2019/12/24)
Novel oxime-ether tethered cyclopropanes, when exposed to Yb(OTf)3 and heat, annulate to generate hydropyrrolo-oxazines products that can be taken to their respective pyrrolidines via hydrogenative N?O bond cleavage. The hydropyrrolo-oxazines are generated in a diastereoselective manner isolating the cis or trans product based on the temperature of the reaction. 20 examples of selective cis and trans hydropyrrolo-oxazines were generated in high yields by temperature control.
