7501-57-7Relevant academic research and scientific papers
α-Chlorobenzylation of Nitroarenes via Vicarious Nucleophilic Substitution with Benzylidene Dichloride: Umpolung of the Friedel-Crafts Reaction
Brze?kiewicz, Jakub,Loska, Rafa?,Makosza, Mieczys?aw
, p. 8499 - 8508 (2018/06/25)
Readily available α,α-dichlorotoluenes enter a vicarious nucleophilic substitution (VNS) reaction with electron-deficient arenes to give α-chlorobenzylated nitrobenzenes, as well as six- and five-membered heterocycles. Oxidation of the initially formed α-chlorobenzylic carbanions instead of protonation results in formation of diaryl ketones, providing a means for overall nucleophilic C-H benzoylation of electron-deficient aromatic rings. Alternatively, benzoylated nitroarenes can be obtained via the reaction of isolated α-chlorodiarylmethanes with sodium azide.
Highly diastereoselective arylation of (S)-mandelic acid enolate: Enantioselective synthesis of substituted (R)-3-hydroxy-3-phenyloxindoles and (R)-benzylic acids and synthesis of nitrobenzophenones
Barroso, Santiago,Blay, Gonzalo,Cardona, Luz,Fernandez, Isabel,Garcia, Begona,Pedro, Jose R.
, p. 6821 - 6829 (2007/10/03)
An easy access to substituted (R)-3-hydroxy-3-phenyloxindoles, (R)-benzylic acids, and benzophenones is described. The reaction of the lithium enolate of the (2S,5S)-cis-1,3-dioxolan-4-one derived from optically active (S)-mandelic acid and pivalaldehyde with several o- and p-halonitrobenzenes proceeds readily to give the corresponding arylation products in good yields and diastereoselectivities. The reduction of the nitro group with Zn/HCl/EtOH in the o-nitro arylation products with concomitant intramolecular aminolysis of the dioxolanone moiety leads directly to enantiomerically pure (R)-3-hydroxy-3- phenyloxindoles. On the other hand the basic hydrolysis of the dioxolanone moiety in all the arylation products (ortho and para) leads to enantiomerically pure substituted (R)-benzylic acids. The oxidative decarboxylation of these latter with oxygen as terminal oxidant in the presence of pivalaldehyde and the Co(III)-Me2opba complex as catalyst gives substituted nitrobenzophenones.
Mandelic Acid as Synthetic Equivalent of Benzoyl Carbanion. Synthesis of Nitrobenzophenones
Blay, Gonzalo,Cardona, Luz,Fernández, Isabel,Michelena, Raquel,Pedro, José R.,Ramírez, Teresa,Ruiz-García, Rafael
, p. 2325 - 2328 (2007/10/03)
Nitrobenzophenones are prepared from a mandelic acid dioxolanone. The sequence starts with the aromatic nucleophilic substitution of the enolate of the dioxolanone onto p-fluoronitrobenzenes, followed by hydrolysis of the acetal moiety and oxidative decarboxylation of the resulting α-hydroxyacids. The whole sequence involves the use of mandelic acid as synthetic equivalent of the benzoyl carbanion.
Reactions of 1-(benzotriazol-1-yl)-1-phenoxyalkane and (benzotriazol-1- yl)ethoxyphenylmethane anions with nitroarenes: A new approach to alkyl and aryl p-nitroaryl ketones
Katritzky, Alan R.,Chassaing, Christophe,Toader, Dorin,Gill, Katherine
, p. 504 - 505 (2007/10/03)
p-Nitroaryl alkyl ketones and p-nitroaryl aryl ketones are prepared regioselectively by reactions of non-functionalized nitroarenes and benzotriazole stabilized carbanions.
