50314-86-8Relevant academic research and scientific papers
Photocatalyzed Triplet Sensitization of Oximes Using Visible Light Provides a Route to Nonclassical Beckmann Rearrangement Products
Zhang, Xiao,Rovis, Tomislav
, p. 21211 - 21217 (2021/12/27)
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.
Stereospecific synthesis of 1,5-disubstituted tetrazoles from ketoximes via a Beckmann rearrangement facilitated by diphenyl phosphorazidate
Ishihara, Kotaro,Shioiri, Takayuki,Matsugi, Masato
supporting information, p. 1295 - 1298 (2019/04/13)
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.
Synthesis and Beckmann rearrangement of novel (Z)-2-organylselanyl ketoximes: promising agents against grapevine anthracnose infection
Waskow, Bianca,Mano, Renata A.,Giacomini, Rafaela X.,Oliveira, Daniela H.,Schumacher, Ricardo F.,Wilhelm, Ethel A.,Luchese, Cristiane,Savegnago, Lucielli,Jacob, Raquel G.
, p. 5575 - 5580 (2016/11/25)
We present here the synthesis of novel (Z)-2-organylselanyl ketoximes by nucleophilic substitution reaction of E/Z mixtures of 2-bromo ketoximes with nucleophilic species of selenium, which were generated in situ by simple cleavage of diorganyl diselenides with NaBH4using ethanol/THF as solvent. The new 2-organylselanyl ketoximes were synthesized in moderate to good yields and with selectivity for the (Z)-configuration. The synthesized (Z)-2-arylselanylacetophenone oximes were submitted to the Beckmann rearrangement, furnishing the corresponding N-aryl-2-(selanyl)acetamides. (Z)-1-Phenyl-2-(phenylselanyl) ketoxime has antifungal activity against Sphaceloma ampelinum and a good level of antioxidant activity in vitro in DPPH, ABTS, FRAP and lipid peroxidation assays.
Asymmetric synthesis of nonracemic primary amines via spiroborate-catalyzed reduction of pure (E)- and (Z)-O-benzyloximes: Applications toward the synthesis of calcimimetic agents
Ou, Wenhua,Espinosa, Sandraliz,Meléndez, Héctor J.,Farré, Silvia M.,Alvarez, Jaime L.,Torres, Valerie,Martínez, Ileanne,Santiago, Kiara M.,Ortiz-Marciales, Margarita
, p. 5314 - 5327 (2013/07/25)
Highly enantiopure (1-aryl)- and (1-naphthyl)-1-ethylamines were synthesized by the borane-mediated reduction of single-isomeric (E)- and (Z)-O-benzyloxime ethers using the stable spiroborate ester derived from (S)-diphenyl valinol and ethylene glycol as the chiral catalyst. Primary (R)-arylethylamines were prepared by the reduction of pure (Z)-ethanone oxime ethers in up to 99% ee using 15% of catalyst. Two convenient and facile approaches to the synthesis of new and known calcimimetic analogues employing enantiopure (1-naphthalen-1-yl)ethylamine as chiral precursor are described.
Synthesis of oximes with NH2OH.HCl/DOWEX(R)50WX4 system
Setamdideh, Davood,Khezri, Behrooz,Esmaeilzadeh, Seyran
, p. 1119 - 1124 (2012/10/30)
The oximation of a variety of carbonyl compounds was efficiently carried out with DOWEX(R)50WX4/NH2OH·HCl system. The reactions were performed in ethanol to give Z-aldoximation isomers of aldehydes and E-oximaton of acetophenone derivatives in a perfect selectively. The oximation of compounds with two carbonyl groups was carried out selectively on one carbonyl moiety. Also, the oximation of aldehydes over ketones has been accomplished successfully by this system.
Intermolecular cope-type hydroamination of alkenes and alkynes
Beauchemin, Andre M.,Moran, Joseph,Lebrun, Marie-Eve,Seguin, Catherine,Dimitrijevic, Elena,Zhang, Lili,Gorelsky, Serge I.
, p. 1410 - 1413 (2008/12/23)
(Chemical Equation Presented) Keep it simple! Intermolecular hydroamination can be achieved simply upon heating alkynes and alkenes with aqueous hydroxylamine. Alkynes react to afford oximes in good to excellent yields, and the formation of Markovnikov products is favored. A mechanism involving Cope-type hydroamination followed by bimolecular proton transfer is suggested and supported by DFT studies.
(E)-Phenyl- and -heteroaryl-substituted O-benzoyl-(or acyl)oximes as lipoprotein-associated phospholipase A2 inhibitors
Jeong, Tae-Sook,Kim, Mi Jeong,Yu, Hana,Kim, Kyung Soon,Choi, Joong-Kwon,Kim, Sung-Soo,Lee, Woo Song
, p. 1525 - 1527 (2007/10/03)
A series of (E)-phenyl- and -heteroaryl-substituted O-benzoyl- (or acyl)oximes 3a-n were synthesized for evaluating their human lipoprotein-associated phospholiphase A2 (Lp-PLA2) inhibitory activities. The less lipophilic derivatives 3a-c showed the most potent in vitro inhibitory activity on human Lp-PLA2.
Selective synthesis of E and Z isomers of oximes
Sharghi,Sarvari
, p. 99 - 101 (2007/10/03)
The highly stereoselective conversion of aldehydes and ketones to their corresponding oximes with hydroxylamin hydrochloride are catalyzed by CuSO4 and K2CO3. This method occurs under mild reaction conditions with high yields.
Ketoxime carbonates and process for the synthesis of ketoxime carbonates generally
-
, (2008/06/13)
This invention relates to novel ketoxime carbonates and a process for the synthesis of ketoxime carbonates generally. Ketoxime carbonates are useful in a variety of applications. They may be used for example as pesticides, pharmaceuticals, weed control ag
Direct carbohydroximoylation of aromatics with primary nitroalkanes in triflic acid (TFSA)
Coustard, Jean-Marie,Jacquesy, Jean-Claude,Violeau, Bruno
, p. 8085 - 8086 (2007/10/02)
Primary nitroalkanes react with aromatics in triflic acid to yield arylated oximes at 70-80°C.
