Ambient formaldehyde measurements made at a remote marine boundary layer site during the NAMBLEX campaign – a comparison of data from chromatographic and modified Hantzsch techniques T. J. Still, S. Al-Haider, P. W. Seakins, R. Sommariva, J. C. Stanton, G. Mills, and S. A. Penkett School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK School of Environmental Sciences, University of East A...

The use of domino and multicomponent reactions in asymmetric synthesis is constantly increasing nowadays. This allows for the synthesis of complex molecules in a single synthetic sequence, usually with high atom economy. Herein, we report three examples of new asymmetric tandem reactions recently developed in our laboratories, giving rise to new families of enantiomerically enriched fluorinated...

The first enantioselective organocatalytic hydride reduction has been accomplished. The use of iminium catalysis has provided a new organocatalytic strategy for the enantioselective reduction of beta,beta-substituted alpha,beta-unsaturated aldehydes to generate beta-stereogenic aldehydes. The use of imidazolidinone 2 as the asymmetric catalyst has been found to mediate the transfer of hydrogen ...

The title mol-ecule, C(17)H(19)NO(5), was prepared by a Hantzsch dihydro-pyridine synthesis from 4-hy-droxy-benzaldehyde, methyl acetoacetate and NH(4)HCO(3). In the mol-ecular structure of the title compound, the dihydro-pyridine ring adopts a flattened boat conformation and the plane of the base of the boat forms a dihedral angle of 80.8 (2)° with the aromatic six-membered ring. The packing i...

The synthesis of a novel dihydropyridine derivatives bearing dimedone as an excellent precursor has been achieved by applying three component Hantzsch condensation. The newly synthesized compounds were characterized by IR, NMR, Mass spectra and also by C, H, N analyses. All synthesized compounds undergo docking studies and biological screening for antimicrobial activity against Gram-positive ba...

A protocol for the synthesis of 1,4-dihydropyridines (Hantzsch type-products) was developed by means of a three-component condensation of an aldehyde, a β-dicarbonyl compound, ammonium acetate and nano Al2O3/KF as catalyst. This reaction was carried out under different conditions including i) solvent-free ii) and reflux in different solvents. In all conditions, the desired products were obtaine...

The classical Hantzsch reaction is one of the simplest and most economical methods for the synthesis of biologically important and pharmacologically useful 1,4-dihydropyridine derivatives. Bismuth nitrate pentahydrate under microwave irradiation is proven to act as a very efficient catalyst for a one-pot, three-component synthesis of 1,4-dihydropyridines in excellent yields from diverse amines/...

Cholesterol is measured by mixing 5 mul of sample with 350 mul of a reagent consisting of phenol, 4-aminoantipyrine, and the enzymes cholesterol oxidase, cholesterol esterase, and peroxidase. After 12 min, the resulting quinoneimine is measured at 520 nm. Readings and cholesterol concentrations are linearly related up to 4.0 g/liter. Lipemic sera and samples containing uric acid (up to 200 mg/l...