N-(Iodopropenyl)-octahydrobenzo[f]- and -[g]quinolines: synthesis and adrenergic and dopaminergic activity studies

Streamlined Stereoselective Entry to (-)-Quinagolide and to 3-Substituted Octahydrobenzo[g]-Quinolines

A very short stereoselective synthesis of enantiomerically pure (3S, 4aS, 10aR)-quinagolide has been developed. The key steps involved are a copper-catalyzed regioselective arylation of (S)-epichlorohydrin with 1,6-dimethoxynaphthalene and a diastereoselective trans-reduction of a cyclic enamine intermediate. The possibility to use both enantiomers of epichlorohydrin and the diastereodivergency found in the reduction process paves the way for a general preparation also in the nonracemic form of chiral trans-fused 3-substituted octahydrobenzo[g]quinolines that are privileged structures in medicinal chemistry.

Development of an asymmetric formal synthesis of (-)-quinagolide via enzymatic resolution and stereoselective iminium ion reduction

The stereoselective reduction of a diastereoisomeric mixture of benzo[g]octahydroquinolinium ion was examined in detail. A diastereoselective borohydride reduction in combination with an efficient deacylative enzymatic resolution of its β-aminoester precursor are the key steps for a stereoselective installation of the three chiral centres present in the (3S,4aS,10aR)-eutomer of the medicinal drug quinagolide. The obtained data paves the way for an easy and practical attainment of chiral 3-substituted octahydrobenzo[g]quinolines that are privileged structures in medicinal chemistry.

Research progress in pharmacological activities and structure-activity relationships of tetralone scaffolds as pharmacophore and fluorescent skeleton

The tetralone and tetralone derivatives, as crucial structural scaffolds of potential novel drugs targeted at multiple biological end-points, are normally found in several natural compounds and also, it can be used as parental scaffold and/or intermediate for the synthesis of a series of pharmacologically active compounds with a broad-spectrum of bioactivities including antibacterial, antitumor, CNS effect and so on. Meanwhile, SAR information of its analogues has drawn attentions among medicinal chemists, which could contribute to the further research related to tetralone derivatives aimed at multiple targets. This review encompasses pharmacological activities, SAR analysis and docking study of tetralone and its derivatives, expecting to provide a general retrospect and prospect on tetralone derivatives.

Cis- and trans-N-benzyl-octahydrobenzo[g]quinolines. Adrenergic and dopaminergic activity studies

In vitro assays on a series of cis- and trans-octahydrobenzo[g]quinolines indicated an unusual trend of affinities at the dopaminergic receptors and alpha adrenoceptors. The trans N-benzyl analogues exhibited affinity at the alpha2 as well as the D1-like receptors whereas their N-unsubstituted congeners showed a distinct preference for the alpha2 adrenoceptor. Enhanced activity for the alpha2 receptors was also exhibited by the cis N-benzylated isomers. These observations are interpreted by theoretical calculations.

A rapid computational method for lead evolution: description and application to alpha(1)-adrenergic antagonists

The high failure rate of drugs in the development phase requires a strategy to reduce risks by generating lead candidates from different chemical classes. We describe a new three-dimensional computational approach for lead evolution, based on multiple pharmacophore hypotheses. Using full conformational models for both active and inactive compounds, a large number of pharmacophore hypotheses are analyzed to select the set or "ensemble" of hypotheses that, when combined, is most able to discriminate between active and inactive molecules. The ensemble hypothesis is then used to search virtual chemical libraries to identify compounds for synthesis. This method is very rapid, allowing very large virtual libraries on the order of a million compounds to be filtered efficiently. In applying this method to alpha(1)-adrenergic receptor ligands, we have demonstrated lead evolution from heterocyclic alpha(1)-adrenergic receptor ligands to highly dissimilar active N-substituted glycine compounds. Our results also show that the active N-substituted glycines are part of our smaller filtered library and thus could have been identified by synthesizing only a portion of the N-substituted glycine library.