2014-61-1Relevant academic research and scientific papers
Complex, degradable polyester materials via ketoxime ether-based functionalization: Amphiphilic, multifunctional graft copolymers and their resulting solution-state aggregates
Iha, Rhiannon K.,Van Horn, Brooke A.,Wooley, Karen L.
, p. 3553 - 3563 (2010)
Degradable, amphiphilic graft copolymers of poly(ε-caprolactone)- grarf-poly(ethylene oxide), PCL-g-PEO, were synthesized via a grafting onto strategy taking advantage of the ketones presented along the backbone of the statistical copolymer poly(ε-caprolactone)-co-(2-oxepane-1, 5-dione), (PCLco-OPD). Through the formation of stable ketoxime ether linkages, 3 kDa PEO grafts and p-methoxybenzyl side chains were incorporated onto the polyester backbone with a high degree of fidelity and efficiency, as verified by NMR spectroscopies and GPC analysis (90% grafting efficiency in some cases). The resulting block graft copolymers displayed significant thermal differences, specifically a depression in the observed melting transition temperature, T m, in comparison with the parent PCL and PEO polymers. These amphophilic block graft copolymers undergo self-assembly in aqueous solution with the P(CL-coOPD-co-(OPD-g-PEO)) polymer forming spherical micelles and a P(CL-co-OPD-co-(OPD-g-PEO)-co-(OPD-g-pMeOBn)) forming cylindrical or rod-like micelles, as observed by transmission electron microscopy and atomic force microscopy.
Synthesis, Crystal Structure, Herbicidal Activity, and SAR Study of Novel N-(Arylmethoxy)-2-chloronicotinamides Derived from Nicotinic Acid
Yu, Chen-Sheng,Wang, Qiao,Bajsa-Hirschel, Joanna,Cantrell, Charles L.,Duke, Stephen O.,Liu, Xing-Hai
, p. 6423 - 6430 (2021/06/28)
Nicotinic acid, also known as niacin, is a natural product, which is widely found in plants and animals. To discover novel natural-product-based herbicides, a series of N-(arylmethoxy)-2-chloronicotinamides were designed and synthesized. Some of the new N-(arylmethoxy)-2-chloronicotinamides exhibited excellent herbicidal activity against Agrostis stolonifera (bentgrass) at 100 μM. Compound 5f (2-chloro-N-((3,4-dichlorobenzyl)oxy)nicotinamide) possessed excellent herbicidal activity against Lemna paucicostata (duckweed), with an IC50 value of 7.8 μM, whereas the commercial herbicides clomazone and propanil had values of 125 and 2 μM, respectively. The structure-activity relationships reported in this paper could be used for the development of new herbicides against monocotyledonous weeds.
N-(benzyloxy)-2-chloronicotinamide compound as well as preparation method and application thereof
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Paragraph 0016; 0035-0036, (2021/06/23)
The invention belongs to the technical field of chemical synthesis and medicine application, and particularly relates to preparation and application of an N-(benzyloxy)-2-chloronicotinamide compound. The preparation method comprises the following steps: reacting phthalic anhydride with hydroxylamine, then reacting with triethylamine for acidification to prepare N-hydroxyphthalimide, then carrying out substitution and hydrazinolysis, and finally reacting with dichloronicotinoyl chloride to prepare the N-(benzyloxy)-2-chloronicotinamide compound. The preparation method disclosed by the invention is simple and convenient to operate, the structure of the obtained product is confirmed by a nuclear magnetic hydrogen spectrum, herbicidal activity tests are carried out on the obtained 15 target products, and results show that all target compounds have an obvious inhibition effect on the seeds of the Agrostis matsumurae under the concentration of 1mM, and the inhibition effect reaches 100%; and along with the decrease of the concentration, even if the concentration reaches 100 [mu] M, the target compound can still show good herbicidal activity.
Palladium-catalyzed regio- And stereoselective access to allyl ureas/carbamates: Facile synthesis of imidazolidinones and oxazepinones
Banerjee, Prabal,Saha, Debarshi,Taily, Irshad Maajid
supporting information, p. 6564 - 6570 (2020/11/10)
Typically, transition metal catalysis enforces the stereodefined outcome of a reaction. Here we disclose the palladium-catalyzed regio- and stereoselective access to allylic ureas/carbamates and their further exploitation to diverse cyclic structures under operationally simple reaction conditions. This protocol features palladium-catalyzed decarboxylative amidation of highly modular VECs with good to excellent yield, minimal waste production, wide substrate scope, and low catalyst loading. In follow-up chemistry, we demonstrated the debenzylation of vinylic imidazolidinones to N-hydroxycyclic ureas and regioselective derivatization towards the facile synthesis of halohydrins and oxiranes under mild reaction conditions in good to excellent yields. This journal is
Regio-Divergent C—H Alkynylation with Janus Directing Strategy via Ir(III) Catalysis
Li, Xianwei,Liang, Guangxin,Shi, Zhang-Jie
supporting information, p. 929 - 934 (2020/06/02)
Directing strategy has been extensively exploited to maintain activity and selectivity for the rapid access to functionalized molecules and pharmaceutical targets. However, ‘one-to-one’ activation model was usually achieved through traditional directing strategy. Herein, we achieved ‘one-to-two’ activation model by slight modification of simple and practical ketoxime and amide functionality. With judicious choice of directing groups, Csp3—H and Csp2—H bond alkynylation reaction, and more significantly, dehydrogenative Csp3—H alkynylation, were realized, enabling the regio-divergent late-stage modifications of pharmaceuticals.
SUBSTITUTED 1-HYDROXY-PYRIDIN-2(1H)-ONES, AND METHODS OF MAKING AND USING SAME
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Paragraph 0225-0226, (2019/06/17)
The present invention includes novel substituted 1-hydroxy-pyridin-2(1H)-ones, which can be used to treat or prevent hepatitis B virus (HBV) infections in a patient. In certain embodiments, the compounds and compositions of the invention inhibit HBV RNAse H activity.
Catalytic asymmetric aza-Michael addition of fumaric monoacids with multifunctional thiourea/boronic acids
Michigami, Kenichi,Murakami, Hiroki,Nakamura, Takeru,Hayama, Noboru,Takemoto, Yoshiji
supporting information, p. 2331 - 2335 (2019/03/06)
The first chemical enantioselective synthesis of N-hydroxyaspartic acid derivatives using chiral multifunctional thiourea/boronic acid organocatalysts was developed. A series of fumaric monoacids underwent an intermolecular asymmetric aza-Michael addition of O-alkyl hydroxylamines in excellent regioselectivity. The addition of another carboxylic acid raised the enantiomeric enrichment up to 97% ee. O-Deprotection of the aza-Michael adduct provided an aspartate-derived hydroxylamine fragment applicable for KAHA (α-keto acid-hydroxylamine) ligation.
Design, synthesis and structure-activity relationship evaluation of novel LpxC inhibitors as Gram-negative antibacterial agents
Ding, Shi,Dai, Rui-Yang,Wang, Wen-Ke,Cao, Qiao,Lan, Le-Fu,Zhou, Xian-Li,Yang, Yu-She
supporting information, p. 94 - 102 (2017/12/15)
LpxC inhibitors are new-type antibacterial agents developed in the last twenty years, mainly against Gram-negative bacteria infections. To develop novel LpxC inhibitors with good antibacterial activities and biological metabolism, we summarized the basic skeleton of reported LpxC inhibitors, designed and synthesized several series of compounds and tested their antibacterial activities against Escherichial coli and Pseudomonas aeruginosa in vitro. Structure-activity relationships have been discussed in this article. The metabolism stability of YDL-2, YDL-5, YDL-8, YDL-14, YDL-20–YDL-23 have been evaluated in liver microsomes, which indicated that the 2-amino isopropyl group may be a preferred structure than the 2-hydroxy ethyl group in the design of LpxC inhibitors.
O-benzyl-N-(9-acridinyl)hydroxylamines
Johnson, Alyssa L.,Duncan, Nathan,Mosher, Michael D.
, p. 139 - 148 (2018/06/27)
A series of O-benzyl-N-(9-acridinyl)hydroxylamines was prepared, isolated, and evaluated for biological activity using both thermal denaturation and MTT assays. Changes in the thermal denaturation temperature of genomic calf-thymus DNA ranged from +6.6 °C to +20.2 °C. MTT assays on SNB-19 glioblastoma cells provided biological activity that ranged from 17.4 μM to 33.2 μM. Both evaluation methods of biological activity indicate that substitution of the benzyl group by either electron-withdrawing or electron-donating groups provides a measureable benefit in these assays. The two assays agreed on the magnitude of the interaction for each substitution pattern.
Visible-Light-Mediated Iminyl Radical Generation from Benzyl Oxime Ether: Synthesis of Pyrroline via Hydroimination Cyclization
Usami, Kaoru,Yamaguchi, Eiji,Tada, Norihiro,Itoh, Akichika
supporting information, p. 5714 - 5717 (2018/09/21)
The treatment of an O-(4-methoxybenzyl) oxime ether bearing an olefin substituent and 1-chloroanthraquinone (1-Cl-AQN) catalyst in 2-butanone under visible-light irradiation affords pyrroline via an iminyl radical intramolecular hydroimination. Mechanistic studies indicate that iminyl radical generation mainly proceeds by hydrogen abstraction of the photocatalyst from the benzyl position of the oxime. Moreover, the hydrogen atom was identified in circulation from the benzylic position of the substrates between AQN and 2-butanone to quench the carbon radical without requiring any additional reagents.
