52939-94-3Relevant academic research and scientific papers
Copper-Catalyzed Carbonyl Group Controlled Coupling of Isatin Oximes with Arylboronic Acids To Prepare N-Aryloxindole Nitrones
Mo, Xue-Ling,Chen, Chun-Hua,Liang, Cui,Mo, Dong-Liang
, p. 150 - 159 (2017/11/28)
A variety of (E)-N-aryloxindole nitrones were prepared in good to excellent yields by using a copper-catalyzed coupling reaction of isatin oximes and arylboronic acids under mild conditions. Various arylboronic acids that contain sensitive functional groups were tolerated in the transformation, and detailed studies show that the carbonyl group of the isatin oximes serves as a ligand to control the formation of the (E)-oxindole nitrones. This method to prepare (E)-N-aryloxindole nitrones was easily performed on a gram scale and efficiently used to synthesize estrone-derived oxindole nitrone in high yield.
DDQ-promoted direct transformation of benzyl hydrocarbons to amides via tandem reaction of the CDC reaction and Beckmann rearrangement
Qiu, Jun,Zhang, Ronghua
supporting information, p. 6008 - 6012 (2013/09/12)
An atom-efficient and transition metal-free approach to amides from the corresponding benzyl hydrocarbons through C-H and C-C bond cleavage has been developed. Mechanistic studies have shown that a DDQ-promoted cross-dehydrogenative coupling (CDC) reaction with subsequent oxidation and rearrangement are involved in this transformation. The Royal Society of Chemistry.
Pyridine synthesis from oximes and alkynes via rhodium(iii) catalysis: Cp* and Cpt provide complementary selectivity
Hyster, Todd K.,Rovis, Tomislav
supporting information; experimental part, p. 11846 - 11848 (2011/12/02)
The synthesis of pyridines from readily available α,β- unsaturated oximes and alkynes under mild conditions and low temperatures using Rh(iii) catalysis has been developed. It was found that the use of sterically different ligands allows for complementary selectivities to be achieved.
Rhodium(III)-catalyzed synthesis of isoquinolines from aryl ketone o -acyloxime derivatives and internal alkynes
Too, Pei Chui,Wang, Yi-Feng,Chiba, Shunsuke
supporting information; experimental part, p. 5688 - 5691 (2011/03/23)
A synthetic method of isoquinolines from aryl ketone O-acyloxime derivatives and internal alkynes has been developed using [Cp*RhCl 2]2 - NaOAc as the potential catalyst system. The present transformation is carried out by a redox-neutral sequence of C - H vinylation via ortho-rhodation and C - N bond formation of the putative vinyl rhodium intermediate on the oxime nitrogen, where the N - O bond of oxime derivatives could work as an internal oxidant to maintain the catalytic cycle.
Friedel-Crafts-type reactions involving di- and tricationic species. Onium-allyl dications and O,O-diprotonated aci-nitro species bearing a protonated carbonyl group
Ohwada, Tomohiko,Yamagata, Naoko,Shudo, Koichi
, p. 1364 - 1373 (2007/10/02)
Stable carbocations do not react with nonactivated benzenes. For example, acetophenone does not react with benzene in the presence of trifluoromethanesulfonic acid (TFSA), while trifluoroacetophenone does do so under acidic conditions owing to activation of the electrophilicity of the hydroxycarbenium cation by the trifluoromethyl group. This and other studies suggest that an electron-withdrawing substituent on the cationic center increases the reactivity toward benzenes. In this paper, involvement of multiply positively charged (dicationic and tricationic) species, which have sufficient electrophilicity toward benzene, is demonstrated in the acid-catalyzed reactions of cinnamaldehyde and its derivatives and also in the acid-catalyzed reactions of nitromethanes. The species formed from cinnamaldehyde, cinnamaldimine, cinnamaldoxime, and their derivatives in TFSA or TFSA-SbF5 have an adequate reactivity toward benzene. O-Protonated cinnamaldehyde and its derivatives, N-protonated cinnamaldimine, and N,N-dimethylcinnamaldiminium salt do not react with benzene. Since a strong acid catalyst is required for the reactions, participation of doubly protonated species, onium-allyl dications, is proposed. Ab initio calculations of (1) the donor-acceptor interaction energies of a neutral donor (such as water and ammonia) and a doubly charged allyl dication and (2) proton affinities demonstrated that the ammonium-allyl dication is more stable than the oxonium-allyl dication, in accordance with the experimental observation. Nitronic acids also react with benzene at the ipso position with respect to the nitro group to give the phenylated oximes in the presence of TFSA. The reaction with benzene is not catalyzed by trifluoroacetic acid, which is sufficiently acidic to monoprotonate a nitronic acid to the protonated aci-nitro form. The reaction requires a stronger acid, trifluoromethanesulfonic acid, suggesting intervention of the dication formed by O,O-diprotonation of acinitroalkanes rather than the monoprotonated aci-nitroalkane. As a result of further study on the phenylation reactions, we found a facile phenylation reaction of nitromethanes substituted with an electron-withdrawing group, catalyzed by TFSA, to give phenylated α-carbonyloximes in high yields. A triply positively charged cation, an O,O-diprotonated aci-nitro species bearing a protonated ethoxycarbonyl group, which can react with nonactivated benzene, is proposed to be an intermediate in this reaction.
Ba(OH)2 AS THE CATALYST IN ORGANIC REACTIONS-PART X-REACTION OF CHALCONE WITH HYDROXYLAMINE
Sinisterra, J. V.,Marinas, J. M.
, p. 293 - 302 (2007/10/02)
The reaction of several chalcones with hydroxylamine has been studied.A systematic catalytic study of the synthetic process has been accomplished.The different experimental conditions have been studied.The process catalyzed in the homogeneous phase gives
Benzenesulfonylcarbonitrile Oxide. 4. Substitution Reactions of 3-(Phenylsulfonyl)isoxazolines
Wade, P. A.,Yen, H.-K.,Hardinger, S. A.,Pillay, M. K.,Amin, N. V.,et al.
, p. 1796 - 1800 (2007/10/02)
3-(Phenylsulfonyl)isoxazolines, readily obtained from alkenes by cycloaddition with benzenesulfonylcarbonitrile oxide, undergo a variety of substitution reactions.Alkyl, aryl, and acetylenic lithium reagents, cyanide, lithium or sodium alkoxides, and sodi
Methylthiomethyl Nitrones from the E- and Z-Oximes of E-Chalcone and Phenyl Vinyl Ketone: -Dipolar Cyclisations
Ooi, Ngan Sim,Wilson, David A.
, p. 4726 - 4736 (2007/10/02)
The E-oximes of E-chalcone (1,3-diphenylpropenone; benzalacetophenone) and phenyl vinyl ketone (1-phenylpropenone) were isomerised by alkali in dimethyl sulphoxide to equilibrium mixtures of E- and Z-isomers, from which the pure Z-isomers have been obtain
