- Unusual course of the p-nitrophenyl phosphate esters cleavage by 3-hydroxyiminoalkylpyridinium salts in micellar solutions
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Two types of amphiphilic quaternary 3-pyridinium ketoximes with different position of the hydrophobic alkyl chain were synthesized and tested as hydrolytic micellar catalysts. A considerable positive deviation from the expected first-order curve was observed in the absorbance vs time plot when p-nitrophenyl diphenyl phosphate and p-nitrophenyl diethyl phosphate were hydrolyzed in micellar solutions of the prepared ketoximes under pseudo-first-order reaction conditions.
- Kotoucova, Hana,Mazac, Jiri,Cibulka, Radek,Hampl, Frantisek,Liska, Frantisek
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Read Online
- Stereospecific synthesis of 1,5-disubstituted tetrazoles from ketoximes via a Beckmann rearrangement facilitated by diphenyl phosphorazidate
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A novel method for the stereospecific synthesis of 1,5-disubstituted tetrazoles from ketoximes via the Beckmann rearrangement was developed using diphenyl phosphorazidate (DPPA) as both the oxime activator and azide source. Various ketoximes were transformed into the corresponding 1,5-disubstituted tetrazoles with exclusive trans-group migration and no E-Z isomerization of the ketoxime. This method enables the preparation of 1,5-disubstituted tetrazoles without using toxic or explosive azidation reagents.
- Ishihara, Kotaro,Shioiri, Takayuki,Matsugi, Masato
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supporting information
p. 1295 - 1298
(2019/04/13)
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- An efficient catalytic method for the Beckmann rearrangement of ketoximes to amides and aldoximes to nitriles mediated by propylphosphonic anhydride (T3P)
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An efficient method for the Beckmann rearrangement of ketoximes to amides mediated by a catalytic amount (15 mol %) of propylphosphonic anhydride (T3P) is described. Aldoximes underwent second order Beckmann rearrangement to provide the corresponding nitriles in excellent yields on reacting with T3P (15 mol %) at room temperature. The main advantages of this environmentally friendly protocol include procedural simplicity, and particularly ease of isolation of the products.
- Augustine, John Kallikat,Kumar, Rajesha,Bombrun, Agnes,Mandal, Ashis Baran
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experimental part
p. 1074 - 1077
(2011/03/22)
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- Modulation of PPAR subtype selectivity. Part 2: Transforming PPARα/γ dual agonist into α selective PPAR agonist through bioisosteric modification
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A novel series of oxime containing benzyl-1,3-dioxane-r-2-carboxylic acid derivatives (6a-k) were designed as selective PPARα agonists, through bioisosteric modification in the lipophilic tail region of PPARα/γ dual agonist. Some of the test compounds (6a
- Zaware, Pandurang,Shah, Shailesh R.,Pingali, Harikishore,Makadia, Pankaj,Thube, Baban,Pola, Suresh,Patel, Darshit,Priyadarshini, Priyanka,Suthar, Dinesh,Shah, Maanan,Jamili, Jeevankumar,Sairam, Kalapatapu V.V.M.,Giri, Suresh,Patel, Lala,Patel, Harilal,Sudani, Hareshkumar,Patel, Hiren,Jain, Mukul,Patel, Pankaj,Bahekar, Rajesh
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scheme or table
p. 628 - 632
(2011/03/18)
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- Synthesis of highly substituted pyrroles via nucleophilic catalysis
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Figure presented. A nucleophilic catalysis method providing a concise synthesis of di-, tri-, and tetrasubstituted pyrroles is described. This regioselective one-pot method relies on nucleophilic catalysis of the intermolecular addition of oximes to activ
- Ngwerume, Simbarashe,Camp, Jason E.
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supporting information; experimental part
p. 6271 - 6274
(2010/11/19)
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- Highly enantioselective borane reduction of heteroaryl and heterocyclic ketoxime ethers catalyzed by novel spiroborate ester derived from diphenylvalinol: Application to the synthesis of nicotine analogues
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(Chemical Equation Presented) An asymmetric synthesis for the preparation of nonracemic amines bearing heterocyclic and heteroaromatic rings is described. A variety of important enantiopure thionyl and arylalkyl primary amines were afforded by the borane-mediated enantioselective reduction of O-benzyl ketoximes using 10% of catalyst 10 derived from (S)-diphenylvalinol and ethylene glycol with excellent enantioselectivity, in up to 99% ee. The optimal condition for the first asymmetric reduction of 3- and 4-pyridyl-derived O-benzyl ketoxime ethers was achieved using 30% of catalytic loading in dioxane at 10°C. (S)-N-ethylnornicotine (3) was also successfully synthesized from the TIPS-protected (S)-2-amino-2-pyridylethanol in 97% ee.
- Huang, Kun,Merced, Francisco G.,Ortiz-Marciales, Margarita,Melendez, Hector J.,Correa, Wildeliz,De Jesus, Melvin
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p. 4017 - 4026
(2008/09/21)
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- Enantioselective Strecker-type reaction of phosphinoyl ketimines catalyzed by a chiral Zr-bipyridyldiol catalyst
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An enantioselective Strecker reaction of N-diphenylphosphinoyl ketimines with TMSCN employing a chiral zirconium complex formed from chiral bipyridyl diol 1 as catalyst is described. The catalytic efficiency of chiral ligand 1 with other Lewis acids was also explored. Higher yields (50-85%) with moderate to good enantioselectivities (30-80%) were achieved for a variety of N-diphenylphosphinoyl ketimines.
- Chen, Yi-Jing,Chen, Chinpiao
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experimental part
p. 2201 - 2209
(2009/04/05)
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- Practical chemoenzymatic synthesis of a 3-pyridylethanolamino β3 adrenergic receptor agonist
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A chemoenzymatic synthesis of β3 agonist 1 suitable for large scale preparation is described. The key chiral 3-pyridylethanolamine intermediate (R)-7 was prepared via an improved Neber rearrangement and a yeast-mediated asymmetric reduction. The tetrazolone fragment of the molecule was constructed via a dipolar cycloaddition between 1-(cyclopentyl)-3-propylazide and p-chlorosulfonyl phenylisocyanate. Sulfonamide coupling of these two intermediates under Shotten-Baumann conditions, followed by a borane reduction of the amide afforded 1 in 20-32% overall yield from 3-acetylpyridine.
- Chung, John Y. L.,Ho, Guo-Jie,Chartrain, Michel,Roberge, Chris,Zhao, Dalian,Leazer, John,Farr, Roger,Robbins, Micheal,Emerson, Kateeta,Mathre, David J.,McNamara, James M.,Hughes, David L.,Grabowski, Edward J. J.,Reider, Paul J.
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p. 6739 - 6743
(2007/10/03)
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- Tetrahydropyridine oxime compounds
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Certain N-substituted 1-(1,2,3,6-tetrahydro-3-pyridinyl)oximes and N-substituted 1-(1,2,3,6-tetrahydro-4-pyridinyl)oximes are useful as sigma binding agents for the treatment of depression, psychoses and/or inflammatory diseases.
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- Oxidative Cleavage of Ketoximes with Iodosobenzene Diacetate
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Hypervalent iodine oxidation of ketoximes (1) using iodosobenzene diacetate leads to cleavage of 1 with the formation of corresponding ketones (2) under neutral conditions in good yields.The scope and limitations of the reaction are discussed as well as the mechanism.
- Moriarty, Robert M.,Prakash, Om,Vavilikolanu, Pushra R.
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p. 1247 - 1254
(2007/10/02)
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