this paper is a density functional theory (dft) calculation of intramolecular proton transfer (ipt) in 6-hydroxypicolinic acid (6hpa, 6-hydroxypyridine-2-carboxylic acid) tautomeric forms. the transition state for the enol-to-keto transition is reported in the gas phase and in four different solvents. the planar and non-planar dimer forms of 6hpa keto and enol, respectively, were also studied i...

A regio- and stereoselective intramolecular direct aldol reaction of 2,7-diketones derived from carbohydrates has been developed to construct cycloalkanones , which were dehydrated to obtain heavily oxygenated cycloalkenones .

A regioselective approach for the synthesis of pyrrolopyridinones and pyrroloazepinones is reported employing an Ugi reaction followed by a gold(I) or platinum(II) catalyzed intramolecular hydroarylation.

A facile ligand-free palladium-catalyzed intramolecular Heck reaction of β-hydrogen-containing secondary benzylic bromides was developed, which affords pyrroline derivatives with good regioselectivities.

stable crystalline phosphorus ylides are obtained in excellent yields from the 1:1:1 addition reactionbetween hydantoins or thiohydantoins and dialkyl acetylenedicarboxylates in the presence oftriphenylphosphine. these phosphoranes undergo smooth intramolecular wittig reaction followedby an electrocyclic ring opening to produce dialkyl (e)-2-(2,5-dihydro-5,5-diaryl-2-thioxo-1h-imidazol-4-yl)fum...

The copper-catalyzed ketenimine formation reaction of 1-(o-acetamidophenyl)propargyl alcohols with various sulfonyl azides is found to undergo a concomitant intramolecular nucleophile attack to generate 1,2-dihydro-2-iminoquinolines after aromatization (via elimination of acetyl and hydroxy groups) and tautomerization. The reaction produces 4-substituted and 3,4-unsubstituted title compounds in...

A highly active heterogeneous Pd-nanoparticle catalyst for the intramolecular addition of phenols to alkynes was developed and employed in a continuous flow reaction system. Running the reaction in flow mode revealed reaction kinetics, such as the activation energy and catalyst deactivation, and provides many potential practical advantages.

This paper is a density functional theory (DFT) calculation of intramolecular proton transfer (IPT) in 6-hydroxypicolinic acid (6HPA, 6-hydroxypyridine-2-carboxylic acid) tautomeric forms. The transition state for the enol-to-keto transition is reported in the gas phase and in four different solvents. The planar and non-planar dimer forms of 6HPA keto and enol, respectively, were also studied i...

the imine intermediate generated by the addition of primary amine to the cinnamaldehyde is trapped by the n-isocyaniminotriphenylphosphorane (ph3pnnc) and a carboxylic acid, and leads to the formation of the corresponding iminophosphorane intermediate. the 1,3,4-oxadiazole derivatives are formed via intramolecular aza-wittig reaction of the iminophosphorane intermediate. the reactions were comp...

Starting from conveniently designed dienynes complexed to cobalt, a tandem RCM-intramolecular Pauson-Khand reaction yields tricyclic compounds. The methodology allows the synthesis of 6,5,5 and 7,5,5 systems.