A successful enone version of an intramolecular aza-[3 + 3] annulation reaction is described here. Use of piperidinium trifluoroacetate salt as the catalyst and toluene as the solvent appears to be critical for a successful annulation. We also demonstrated for the first time that microwave irradiation can accelerate aza-[3 + 3] annulation reactions. An attempt to expand the scope of the enone a...

An efficient copper-mediated three-component reaction of 2,3-allenoates or 2-alkynoates, amines, and nitriles affording fully substituted pyrazoles with a very nice diversity has been developed. A tandem conjugate addition, 1,2-addition, and N-N bond formation mechanism has been proposed for this diverse synthesis of pyrazoles based on mechanistic studies.

This review describes our recent efforts in the development of acid-base organocatalysts, (S)-3-(N-isopropyl-N-3-pyridinylaminomethyl) BINOL (6a) and (S)-3-[2-(diphenylphosphino)phenyl] BINOL (13a), with dual activation mechanism for the aza-Morita-Baylis-Hillman (aza-MBH) reaction. In these catalysts, chiral Brønsted acid units are connected with a Lewis base unit via a spacer. The acid-base m...

A transition-metal-free and base-promoted one-pot reaction of ynones with 2-aminobenzonitriles is described. The was initiated through sequential aza-Michael addition/intramolecular annulation to afford various multisubstituted 4-aminoquinolines 4-amino-1,8-naphthyridines in good excellent yields. Operational simplicity, high atom-economy broad substrate scope makes this protocol more attractiv...

This thesis describes the development of peptidic catalysts for stereoselective conjugate addition reactions of aldehydes and ketones to maleimides. In addition, mechanistic aspects of this conjugate addition were investigated and structural aspects of peptidic catalysts of the general H-DPro-Pro-type were studied. From a collection of tripeptides, H-DPro-Pro-Asn-NH2 was found to catalyze the c...

Electrochemical synthesis, structure elucidation and antibacterial evaluation of 9a-aza-9a-chloro-9ahomoerythromycin A were carried out. It was found that the anodic oxidation of 9a-aza-9a-homoerythromycin A via electrogenerated reactive chlorine species leads to the chlorination of lactam nitrogen in high yield provided the pH of the reaction mixture is maintained above 3. NOESY spectra reveal...

The combination of small-molecule catalysis and enzyme represents an underexploited area research with huge potential in asymmetric synthetic chemistry due to both compatibility reaction conditions complementary reactivity. Herein, we describe the telescopic synthesis chiral nitro alcohols starting from commercially available benzaldehyde derivatives through one-pot three-step chemoenzymatic ca...

Background: DNA molecule of the eukaryotic cells is found in the form of a nucleoprotein complex named chromatin. Two epigenetic modifications are critical for transcriptional control of genes, including acetylation and DNA methylation. Hypermethylation of tumor suppressor genes is catalyzed by various DNA methyltransferase enzymes (DNMTs), including DNMT1, DNMT2, and DNMT3. The most well chara...

The title compound, C(25)H(24)N(2)O(3) was prepared by the reaction of (Z)-2-(1H-indol-3-ylmethyl-ene)-1-aza-bicyclo-[2.2.2]octan-3-one with methyl p-(bromo-meth-yl)benzoate, under phase-transfer catalytic (PTC) conditions using triethyl-benzyl-ammonium chloride and 50% w/v aqueous NaOH solution in dichloro-methane. The crystal structure indicates the presence of a double bond with Z geometry c...