3680-28-2Relevant academic research and scientific papers
Selective formation of γ-lactams via C-H amidation enabled by tailored iridium catalysts
Hong, Seung Youn,Park, Yoonsu,Hwang, Yeongyu,Kim, Yeong Bum,Baik, Mu-Hyun,Chang, Sukbok
, p. 1016 - 1021 (2018/03/09)
Intramolecular insertion of met al nitrenes into carbon-hydrogen bonds to form γ-lactam rings has traditionally been hindered by competing isocyanate formation. We report the application of theory and mechanism studies to optimize a class of pentamethylcyclopentadienyl iridium(III) catalysts for suppression of this competing pathway. Modulation of the stereoelectronic properties of the auxiliary bidentate ligands to be more electron-donating was suggested by density functional theory calculations to lower the C-H insertion barrier favoring the desired reaction. These catalysts transform a wide range of 1,4,2-dioxazol-5-ones, carbonylnitrene precursors easily accessible from carboxylic acids, into the corresponding γ-lactams via sp3 and sp2 C-H amidation with exceptional selectivity. The power of this method was further demonstrated by the successful late-stage functionalization of amino acid derivatives and other bioactive molecules.
A safe and selective method for reduction of 2-nitrophenylacetic acid systems to N-aryl hydroxamic acids using continuous flow hydrogenation
Ichire, Ogar,Jans, Petra,Parfenov, Galina,Dounay, Amy B.
, p. 582 - 585 (2017/01/16)
The cyclic hydroxamic acid functional group is critical to the biological activity of numerous natural products and drug candidates. Efficient, reliable, and green synthetic methods to produce cyclic hydroxamic acids are needed. Herein, flow hydrogenation has been explored as a novel approach toward achieving the selective partial reduction of 2-nitrophenylacetic acid to 1-hydroxyindolin-2-one. The bidentate ligand, 1,10-phenanthroline, has been identified as a unique inhibitor for modulating product selectivity in this Pt/C-catalyzed process. Under the newly optimized reaction conditions, the targeted hydroxamic acid is produced with high selectivity (49:1) over the lactam by-product. The scope of the reaction is demonstrated for a variety of 2-nitrophenylacetic acid derivatives.
A Benzisoelenazolone modified pyrrole methyl ester substituted indole ketone compound and use thereof
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Paragraph 0117-0118; 0214-0217, (2016/10/08)
The invention discloses a benzisoselenazolone-modified pyrrolyl formate-substituted indolone compound and a use thereof. The invention depends on and claims the priority of a Chinese patent application 201110105248.0 submitted on April 26, 2011. Through reference, all contents of the Chinese patent application 201110105248.0 are incorporated into the invention. The benzisoselenazolone-modified pyrrolyl formate-substituted indolone compound is shown in the general formula I. The 2-indolone compound provided by the invention has excellent antitumor activity and can be widely used for preparation of antitumor drugs.
Palladium-Catalyzed C-H Activation and Cyclization of Anilides with 2-Iodoacetates and 2-Iodobenzoates: An Efficient Method toward Oxindoles and Phenanthridones
Gandeepan, Parthasarathy,Rajamalli, Pachaiyappan,Cheng, Chien-Hong
, p. 1872 - 1879 (2016/06/15)
A concise approach to the synthesis of oxindoles and phenanthridones from anilides is described. In the presence of catalytic amount of Pd(OAc)2, 2-iodoacetates and 2-iodobenzoates can be used to functionalize ortho C-H bond of anilides, which subsequently undergo intramolecular cyclization to give the products. A possible reaction mechanism that involves a PdII/PdIV catalytic cycle is proposed with the support of detailed mechanistic studies.
CGRP ANTAGONISTS
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Page/Page column 96, (2011/04/18)
The present invention relates to new CGRP-antagonists of general formula I wherein U, V, X, Y, R1, R2 and R3 are defined as stated hereinafter, the tautomers, the isomers, the diastereomers, the enantiomers, the hydrates, the mixtures thereof and the salts thereof and the hydrates of the salts, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases, pharmaceutical compositions containing these compounds, their use and processes for preparing them.
Electrophilic Aromatic Substitution with N-Methoxy-N-acylnitrenium Ions Generated from N-Chloro-N-methoxyamides: Syntheses of Nitrogen Heterocyclic Compounds Bearing a N-Methoxyamide Group
Kawase, Masami,Kitamura, Takahiro,Kikugawa, Yasuo
, p. 3394 - 3403 (2007/10/02)
N-Methoxy-N-acylnitrenium ions (II), generated by treatment of N-chloro-N-methoxyamides with silver carbonate in trifluoroacetic acid, react with arenes to give N-aryl-N-methoxyamides in good yields.In the case of the intramolecular cyclization of N-chloro-N-methoxy-2-phenylacetamides, the mode of cyclization is highly dependent on the nature of ortho or para substituent groups.Nitrenium ions II can primarily attack three positions (C-1, C-2, and C-6) of a phenyl ring.Normally II attack C-6.On the other hand, when the ortho position was occupied with a substituent group, II attacked both C-2 and C-6, in the former case followed by a 1,2-substituent migration, which was proved by a deuterium labeling experiment.Especially, when a methoxy group is substituted on ortho or para position, II attack C-1 due to the effect of the electron-releasing methoxy group to give spiro dienone compounds 39.A general discussion of the utility and mechanistic details of these reactions is presented.
Synthesis of oxindoles from anilines and β-thio carboxylic esters or amides
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, (2008/06/13)
Preparing oxindoles and intermediates therefor by reacting an N-haloaniline with β-thio esters or β-thio amides to form an azasulfonium halide, reacting the azasulfonium halide with a base to form an ortho-[thio-ether (hydrocarbonoxycarbonyl) alkyl]aniline, or a [thio-ether (aminocarbonyl) alkyl]aniline, reacting the orthosubstituted aniline with an acid to form a 3-thio-ether-2-oxindole, and then reducing the 3-thio-ether-2-oxindole with Raney Nickel to form the 2-oxindole.
