Potassium permanganate/ carboxylic acid/ organic solvent: a powerful reagent for c-c bond formation, aryl coupling reactions and enone oxidation ipso-nitration of arylboronic acids with silver nitrite/ tmscl

Fındık, Hamide
The first part of the thesis presents the KMnO4/ carboxylic acid/ organic solvent which is a powerful reagent for C-C bond formation, aryl coupling reactions and enone oxidation. The a¢-acetoxylation of enones and the a-acetoxylation of aromatic ketones were carried out with potassium permanganate and acetic acid, in which acetoxylation products were obtained in 74-96% yields. The same reaction was carried out with carboxylic acids other than acetic acid, which furnished corresponding acyloxy ketones with the same regioselectivity. For the first time, formyloxylation products were synthesized in a 61-85% yield by using formic acid. The potassium permanganate and acetic acid method was also used for aryl coupling reactions. The reaction of arylboronic acids and aryl hydrazines in benzene with potassium permanganate and acetic acid in turn furnished biaryls in a 85-96% yield. We showed that potassium permanganate/carboxylic acid/organic solvent behaves as manganese(III) acetate. In the second part of the thesis, ipso-nitration of arylboronic acids with AgNO2/ TMSCl was performed. Nitration of aromatic compounds is one of the most extensively studied reactions, and nitroaryl moieties play key roles in the physical and chemical properties of many target molecules in organic synthesis. For electrophilic nitration of aromatic compounds, a wide variety of reagents are available to date. Most of them are very strong nitrating agents and often lead to further nitration and mixture of isomers. Since most nitrating agents are oxidants, oxidation of other functional groups can also occur, giving a mixture of products. Thus, a search for milder and selective nitrating agents is a good research goal. In this work, we aimed to apply AgNO2/ TMSCl system to ipso nitration of arylboronic acids.


Benzaldehyde Lyase-Catalyzed Direct Amidation of Aldehydes with Nitroso Compounds
Ayhan, Peruze; Demir, Ayhan Sıtkı (Wiley, 2011-03-07)
Benzaldehyde lyase from the Pseudomonas fluorescens catalyzes the reaction of aromatic aldehydes with nitroso compounds and furnishes N-arylhydroxamic acids in high yields. Aromatic aldehydes and benzoins are converted into enamine-carbanion-like intermediates prior to their reaction with nitroso compounds. The kinetic resolution of rac-2-hydroxy-1,2-diphenylethanones furnished (S)-benzoins and arylhydroxamic acids with high enantioselectivities and conversions.
DEMIR, AS; Tanyeli, Cihangir; URKMEZKARAASLAN, R; SAYRAC, T (Informa UK Limited, 1991-01-01)
Short simple synthesis of alkenoic acid esters and their intramolecular cyclization products, 2H-Pyran-2-ones from enolates of carbonyl compounds and enaminoesters are described.
A facile synthesis of various butenolides
Tanyeli, Cihangir (Informa UK Limited, 2000-01-01)
The synthesis of alpha'-acyloxy-alpha,beta-unsaturated cyclic ketones from the corresponding alpha,beta-unsaturated cyclic ketones by using manganese (III) acetate in combination with 2-chloropropionic acid followed by subsequent Arbuzov and intramolecular Horner-Emmons cyclization reactions provided a convenient synthetic pathway to various butenolides 4a-d.
Synthesis of various camphor-based chiral pyridine derivatives
Işık, Murat; Tanyeli, Cihangir; Department of Chemistry (2005)
Chiral aromatic nitrogen heterocycles are finding many applications in asymmetric organic synthesis, particularly as ligands in the preparation of chiral metal complexes. Since camphor-based chiral auxiliaries are known to be especially effective, a number of pyridines fused to the camphor skeleton have been reported. It is well known that nicotinic acid and its derivatives exhibiting qualitatively the biological activity of nicotinamide, which acts as an electron acceptor in many biological redox reactions...
Metal triflates-catalyzed conjugate addition of homochiral Pyrroles to alpha,beta-unsaturated esters
Unaleroglu, C; Temelli, B; Demir, Ayhan Sıtkı (Georg Thieme Verlag KG, 2004-10-18)
The Friedel-Crafts reaction of homochiral pyrrole derivatives with alpha,beta-unsaturated esters catalyzed by metal triflates furnished conjugate addition products. The best yields were obtained by using yttrium triflate and methyl 4-phenyl-2-oxobut-3-enoate (2a). The addition worked regioselectively at C-5 of pyrrole. The diastereoisomers were separated by column chromatography.
Citation Formats
H. Fındık, “Potassium permanganate/ carboxylic acid/ organic solvent: a powerful reagent for c-c bond formation, aryl coupling reactions and enone oxidation ipso-nitration of arylboronic acids with silver nitrite/ tmscl,” Ph.D. - Doctoral Program, Middle East Technical University, 2009.