Magnesium nitrate as a matrix modifier in the stabilized temperature platform furnace

Chiral N‐Acylhydrazones: Versatile Imino Acceptors for Asymmetric Amine Synthesis

A catalytic system consisting of sodium tungstate and methyltrioctylammonium hydrogensulfate effects oxidation of simple secondary alcohols to ketones using 3—30% H2O2 without any organic solvents. The oxidation can be conducted under entirely halide-free, mildly acidic conditions. A combination of tungstic acid and an appropriate quaternary ammonium salt also effects the alcohol dehydrogenation. The organic/aqueous biphasic reaction allows easy product/catalyst separation. The turnover number, defined as mols of product per mol of catalyst, approaches 77700 (2-octanol) or 179000 (1-phenylethanol), two orders of magnitude higher than any previously reported. Ester, alkyl and t-butyldimethylsilyl ether, epoxy, carbonyl, N-alkyl carboxamide, and nitrile groups are tolerated under the reaction conditions. Secondary alcohols are preferentially oxidized over terminal olefins. Primary alkanols are oxidized directly to carboxylic acids in a moderate to high yield. Benzylic alcohols are selectively oxidized to be...

A Practical Method for Alcohol Oxidation with Aqueous Hydrogen Peroxide under Organic Solvent- and Halide-Free Conditions.

In a search toward new and efficient antidepressants, 1-aryl-3-(4-arylpiperazin-1-yl)propane derivatives were designed, synthesized, and evaluated for 5-HT reuptake inhibition and 5-HT1A receptor antagonism. This dual pharmacological profile should lead, in principle, to a rapid and pronounced enhancement in serotoninergic neurotransmission and consequently to a more efficacious treatment of depression. The design was based on coupling structural moieties related to inhibition of serotonin reuptake, such as gamma-phenoxypropylamines, to arylpiperazines, typical 5-HT1A ligands. In binding studies, several compounds showed affinity at the 5-HT transporter and 5-HT1A receptors. Antidepressant-like activity was initially assayed in the forced swimming test with those compounds with Ki < 200 nM in both binding studies. Functional characterization was performed by measuring the intrinsic effect on rectal temperature in mice and also the antagonism to 8-OH-DPAT-induced hypothermia. The most efficacious compounds (12f, 23gE, 28a, and 28b) were further explored for their ability to antagonize 8-OH-DPAT-induced inhibition of forskolin-stimulated cAMP formation in a cell line expressing the 5-HT1A receptor. Furthermore, the antidepressant-like properties of 12f, 28a, and 28b, which exhibited 5-HT1A receptor antagonistic property in the latter study, were also evaluated in the learned helplessness test in rats. Among these three compounds, 28b (1-benzo[b]thiophene-3-yl)-3-[4-(2-methoxyphenyl)-1-ylpropan-1-ol) showed the higher affinity at both the 5-HT transporter and 5-HT1A receptors (Ki = 20 nM in both cases) and was also active in the other pharmacological tests. Such a pharmacological profile could lead to a new class of antidepressants with a dual mechanism of action and a faster onset of action.

New 1-aryl-3-(4-arylpiperazin-1-yl)propane derivatives, with dual action at 5-HT1A serotonin receptors and serotonin transporter, as a new class of antidepressants.

The palladium assisted transfer reduction of. alpha. ,. beta. -unsaturated nitroalkenes to oximes using ammonium formate

The use of ^(13)C nmr (cmr) spectra for the determination of configurations of oximes is described. The problems
of quantitative analysis of syn-anti mixtures of oximes by cmr, because of differential T_1 and Overhauser
effects, are considered. Chemical shifts for the cmr resonances of a number of aldehydes and ketones are reported.

Klaus Herwig

Papers

Nuclear magnetic resonance spectroscopy. Use of carbon-13 spectra to establish configurations of oximes