- Evaluating thiourea/urea catalyst for enantioselective 6π-photocyclization of acrylanilides
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6π-Photocyclization of acrylanilide with thiourea and urea based organocatalysts were evaluated to develop H-bonding activated photochemical reactions. These photochemical reactions resulted in a 3,4-dihydroquinolin-2-one photoproduct with low enantioselectivity. Photophysical studies revealed catalyst-substrate interactions in the excited state. The low chiral induction is likely due to a combination of low stereodifferentiation with respect to the mode of cyclization of the substrate by the catalyst, formation of an enol intermediate that destroys the chirality and the relative reactivity of the zwitterionic intermediate that competes with enol formation and direct hydrogen atom migration.
- Raghunathan, Ramya,Jockusch, Steffen,Sibi, Mukund P.,Sivaguru
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Read Online
- Photocatalyzed Triplet Sensitization of Oximes Using Visible Light Provides a Route to Nonclassical Beckmann Rearrangement Products
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Oximes are valuable synthetic intermediates for the preparation of a variety of functional groups. To date, the stereoselective synthesis of oximes remains a major challenge, as most current synthetic methods either provide mixtures of E and Z isomers or furnish the thermodynamically preferred E isomer. Herein we report a mild and general method to achieve Z isomers of aryl oximes by photoisomerization of oximes via visible-light-mediated energy transfer (EnT) catalysis. Facile access to (Z)-oximes provides opportunities to achieve regio- and chemoselectivity complementary to those of widely used transformations employing oxime starting materials. We show an enhanced one-pot protocol for photocatalyzed oxime isomerization and subsequent Beckmann rearrangement that enables novel reactivity with alkyl groups migrating preferentially over aryl groups, reversing the regioselectivity of the traditional Beckmann reaction. Chemodivergent N- or O- cyclizations of alkenyl oximes are also demonstrated, leading to nitrones or cyclic oxime ethers, respectively.
- Zhang, Xiao,Rovis, Tomislav
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supporting information
p. 21211 - 21217
(2021/12/27)
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- HETEROCYCLIC COMPOUNDS AND USES THEREOF
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Provided herein are novel heterocyclic compounds, for example, compounds having Formula I, I-P, II, lI-P, or III. Also provided herein are pharmaceutical compositions comprising the compounds and methods of using the same, for example, in inhibiting aldehyde dehydrogenases and/or for treating various cancers, cancer metastasis, type 2 diabetes, pulmonary arterial hypertension (PAH) or neointimal hyperplasia (NIH).
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Paragraph 0298
(2021/07/31)
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- FUSED IMIDAZOLE AND PYRAZOLE DERIVATIVES AS MODULATORS OF TNF ACTIVITY
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A series of substituted benzimidazole, imidazo[1,2-a]pyridine and pyrazolo[1,5-a]pyridine derivatives, and analogues thereof, being potent modulators of human TNFα activity, are accordingly of benefit in the treatment and/or prevention of various human ailments, including autoimmune and inflammatory disorders; neurological and neurodegenerative disorders; pain and nociceptive disorders; cardiovascular disorders; metabolic disorders; ocular disorders; and oncological disorders.
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Page/Page column 179; 180
(2015/06/25)
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- Regiodivergent access to five- and six-membered benzo-fused lactams: Ru-catalyzed olefin hydrocarbamoylation
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We report herein a new strategy of the Ru-catalyzed intramolecular olefin hydrocarbamoylation for the regiodivergent synthesis of five- and six-membered benzo-fused lactams starting from N-(2-alkenylphenyl)formamides. Using a combined catalyst of Ru3
- Li, Bin,Park, Yoonsu,Chang, Sukbok
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p. 1125 - 1131
(2014/02/14)
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- Palladium-catalyzed β-arylation of silyl ketene acetals and application to the synthesis of benzo-fused δ-lactones
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Silyl ketene acetals are shown to be competent nucleophiles in Pd-catalyzed migrative C(sp3)-H arylations. Compared to the parent ester lithium enolates, they possess decreased reactivity but enhanced chemoselectivity. This behavior was exploited through the synthesis of valuable benzo-fused δ-lactones such as 1-isochromanones and dihydrocoumarins.
- Aspin, Sam,Lopez-Suarez, Laura,Larini, Paolo,Goutierre, Anne-Sophie,Jazzar, Rodolphe,Baudoin, Olivier
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supporting information
p. 5056 - 5059
(2013/10/22)
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- Multicomponent multicatalyst reactions (MC)2R: One-pot synthesis of 3,4-dihydroquinolinones
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A Rh/Pd/Cu catalyst system led to an efficient synthesis of dihydroquinolinones in one-pot, two operations. The reaction features the first triple metal-catalyzed transformations in one reaction vessel, without any intermediate workup. The conjugate-addition/amidation/amidation reaction sequence is highly modular, divergent, and practical.
- Zhang, Lei,Sonaglia, Lorenzo,Stacey, Jason,Lautens, Mark
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supporting information
p. 2128 - 2131
(2013/06/05)
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- Ionic diamine rhodium complex catalyzed hydroaminomethylation of 2-allylanilines
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Ionic diamine rhodium complexes catalyze the hydroaminomethylation of 2-allylanilines. The reaction involves initial hydroformylation followed by reductive amination, which provides direct access to 1,2,3,4- tetrahydroquinolines and 2,3,4,5-1H-1-benzazepi
- Okuro, Kazumi,Alper, Howard
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scheme or table
p. 4959 - 4961
(2011/01/12)
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- Convergent synthesis of dihydroquinolones from o-aminoarylboronates
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An efficient and convergent one-step synthesis of substituted dihydroquinolin-2-ones from α,β-unsaturated esters and aminoaryl pinacolboronates under rhodium catalysis is reported. The reaction is easily applicable in parallel synthesis format and provide
- Horn, Joachim,Li, Ho Yin,Marsden, Stephen P.,Nelson, Adam,Shearer, Rachel J.,Campbell, Amanda J.,House, David,Weingarten, Gordon G.
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experimental part
p. 9002 - 9007
(2009/12/22)
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- Preparation of 2-Quinolones by sequential heck reduction-cyclization (HRC) reactions by using a multitask palladium catalyst
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One-pot sequential Heck reduction-cyclization (HRC) reactions leading to the synthesis of substituted 2-quinolones have been developed by using a heterogeneous or mixed homogeneous/heterogeneous multitask palladium catalyst with charcoal as a support. The whole sequence occurs under very mild conditions without the need for additives (ligand or base) by taking advantage of the high reactivity of aryldiazonium salts as "super electrophiles". Recycling experiments showed that the reused heterogeneous Pd°/C catalyst was not able to promote another HRC sequence but was, however, still highly active for hydrogenation, hydrodehalogenation, as well as hydrogenolysis reactions.
- Felpin, Francois-Xavier,Coste, Jerome,Zakri, Cecile,Fouquet, Eric
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experimental part
p. 7238 - 7245
(2010/03/25)
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- The tandem reaction combining radical and ionic processes: an efficient approach to substituted 3,4-dihydroquinolin-2-ones
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3,4-Dihydroquinolin-2-ones are of great importance in the areas of pharmaceuticals. However, the direct intramolecular radical cyclizations of the corresponding amide compounds favor 5-exo products 2. Reports on the radical cyclization reactions producing
- Zhou, Wang,Zhang, Liangren,Jiao, Ning
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experimental part
p. 1982 - 1987
(2009/08/07)
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- The Baylis-Hillman approach to quinoline derivatives
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Baylis-Hillman reactions of 2-nitrobenzaldehydes with various activated alkenes afford adducts that undergo reductive cyclisation to quinoline derivatives. The chemo- and regioselectivity of cyclisation appears to be influenced by the choice of both the substrate and the reagent system, and competing reactions have been observed. The Royal Society of Chemistry 2006.
- Familoni, Oluwole B.,Klaas, Phindile J.,Lobb, Kevin A.,Pakade, Vusumzi E.,Kaye, Perry T.
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p. 3960 - 3965
(2008/09/18)
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- Recyclable selective palladium-catalyzed synthesis of five-, six- or seven-membered ring lactones and lactams by cyclocarbonylation in ionic liquids
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The ionic liquids, BMIM PF6 or BMIM NTf2, are used successfully for the palladium-catalyzed cyclocarbonylation of 2-allylphenols and anilines, 2-vinylphenols, and 2-aminostyrenes. The reaction proceeds cleanly and efficiently to afford high yields of lactones or lactams with good or excellent selectivity for one isomer. The ionic liquid containing the palladium catalyst, and ligand, is recyclable in all cases.
- Ye, Fangguo,Alper, Howard
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p. 1855 - 1861
(2007/10/03)
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- Syntheses and binding affinities of 6-nitroquipazine analogues for serotonin transporter: Part 3. A potential 5-HT transporter imaging agent, 3-(3-[18F]Fluoropropyl)-6-nitroquipazine
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3-(3-[18F]Fluoropropyl)-6-nitroquipazine ([18F]FPNQ) as a 5-HT transporter imaging agents was designed, synthesized, and evaluated. FPNQ was selected due to its potent in vitro biological activity (K i=0.32 nM) in rat brain cortical membranes. The 18F- labeled FPNQ was prepared by reaction of the propyl mesylate as a precursor with tetra-n-butylammonium [18F]fluoride generated under NCA conditions. The precursor mesylate was synthesized from commercially available hydrocarbostyril in nine steps in 21% overall yield. The specific activity of the [18F]FPNQ determined by radioreceptor assay was 27.0 GBq/μmol. Tissue distribution studies in mice showed the highest uptake in the frontal cortex (5.79%ID/g) at 60 min post-injection.
- Lee, Byoung Se,Chu, Soyoung,Lee, Kyo Chul,Lee, Bon-Su,Chi, Dae Yoon,Choe, Yearn Seong,Kim, Sang Eun,Song, Yun Seon,Jin, Changbae
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p. 4949 - 4958
(2007/10/03)
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- Application of Baylis-Hillman methodology in a novel synthesis of quinoline derivatives
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Reaction of 2-nitrobenzaldehyde with vinyl carbonyl compounds in the presence of 1,4-diazabicyclo[2.2.2]octane affords Baylis-Hillman products, catalytic reduction of which results in direct cyclisation to quinoline derivatives.
- Familoni, Oluwole B.,Kaye, Perry T.,Klaas, Phindile J.
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p. 2563 - 2564
(2007/10/03)
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- Regioselective palladium(II)-catalyzed synthesis of five- or seven-membered ring lactones and five-, six- or seven-membered ring lactams by cyclocarbonylation methodology
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2-Allylphenols react with carbon monoxide and hydrogen in the presence of catalytic quantities of a cationic palladium(II) complex [(PCy3)2Pd(H)(H2O)]+BF4- or palladium acetate and 1,4-bis(diphenylpho
- El Ali, Bassam,Okuro, Kazumi,Vasapollo, Giuseppe,Alper, Howard
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p. 4264 - 4270
(2007/10/03)
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- Preparation electrochimique de derives de la quinoleine. II. Electroreduction d'o-nitrobenzylidenes substitues
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Quinoline N-oxydes and N-hydroxyquinolones have been prepared by controlled potential electrolysis of o-nitrobenzylidenes: o-NO2-C6H4-CH=CX2, o-NO2-C6H4-CH=CRX, o-NO2-C6H4-CH=CXY (X and Y being electron withdrawing groups: CO2Et, CN, CONH2, COPh).As a gen
- Chibani, A.,Hazard, R.,Jubault, M.,Tallec, A.
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p. 795 - 802
(2007/10/02)
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- INTRAMOLECULAR AMIDATION OF ARYLALKYLHYDROXAMIC ACIDS
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It is shown that mixtures of two isomeric benzolactams, viz., compounds of the benzamide and anilide type, are formed in the intramolecular amidation of arylalkylhydroxamic acids under the influence of polyphosphoric acid (PPA).A general reaction scheme that includes three pathways, viz., direct amidation, Losen rearrangement of the hydroxamic acids with subsequent cyclization of the isocyanates, and Beckmann rearrangement of the oximes of the cyclic ketones formed in the thermal cleavage of the starting hydroxamic acids in PPA, is proposed on the basis of a study of racemic and optically active arylalkylhydroxamic acids.
- Potapov, V.M.,Dem'yanovich, V. M.,Vendrova, O. E.,Khlebnikov, V. A.
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p. 528 - 533
(2007/10/02)
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