Discovery of the First Potent, Selective 5-Hydroxytryptamine1D Receptor Antagonist

Amino acid chirons: a tool for asymmetric synthesis of heterocycles

As a result of their easy availability in enantiomerically enriched form and their possession of synthetically transformable diverse functional groups, amino acids have been extensively used by synthetic organic and medicinal chemists as a chiral pool for access to heterocycles (monocycles, bicycles or polycycles, either bridged or fused). This review describes the syntheses of diverse asymmetric heterocycles with various membered rings (n = 3-9) followed by benzo or heteroannulated ones, for the period from 1996 to Dec. 2013. It details solution phase synthetic methodologies in which the naturally occurring α-amino acid is incorporated, totally or partially, into the final product.

SnAP reagents for the synthesis of piperazines and morpholines

Substituted piperazines and morpholines are valuable structural motifs in biologically active compounds, but are not easily prepared by contemporary cross-coupling approaches. In this report, we introduce SnAP reagents for the transformation of aldehydes into N-unprotected piperazines and morpholines. This approach offers simple, mild conditions compatible with aromatic, heteroaromatic, aliphatic, and glyoxylic aldehydes and provides mono- and disubstituted N-heterocycles in a single step.

The Concise Guide to PHARMACOLOGY 2013/14: G protein-coupled receptors

The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. The full contents can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.12444/full. G protein-coupled receptors are one of the seven major pharmacological targets into which the Guide is divided, with the others being G protein-coupled receptors, ligand-gated ion channels, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors and Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and the Guide to Receptors and Channels, providing a permanent, citable, point-in-time record that will survive database updates.

Regioselective ring-opening of amino acid-derived chiral aziridines: an easy access to cis-2,5-disubstituted chiral piperazines

An efficient four-step synthetic strategy for cis-2,5-disubstituted chiral piperazines derived from amino-acid-based aziridines is described. The key steps in this strategy are the highly regioselective boron trifluoride diethyl etherate (BF(3)·OEt(2))-mediated ring-opening of less-reactive N-Ts chiral aziridines by α-amino acid methyl ester hydrochloride followed by Mitsunobu cyclization. This protocol has been used in an attempt to construct the piperazine core framework of natural product (+)-piperazinomycin.

4-Methyl-3-nitrobenzaldehyde

In the crystal structure of the title compound, C₈H₇NO₃, mol­ecules are linked through weak inter­molecular C—H⋯O hydrogen bonding.

Selectively N-protected enantiopure 2,5-disubstituted piperazines: avoiding the pitfalls in solid-phase Fukuyama-Mitsunobu cyclizations

An efficient solid-phase route to ring-substituted piperazines from O-linked resin-bound (S)-aziridine-2-methanol is described. Regioselective microwave-assisted aminolysis followed by intramolecular Fukuyama-Mitsunobu cyclization constitute the key features of the protocol. Simple piperazines and diazepanes were readily obtained without preceding N-protection of the acyclic intermediate, whereas attempts to extend this protocol to chiral 2,5-disubstituted piperazines failed. Modifications encompassing N-carbamoylation prior to ring-closure were therefore investigated. However, standard carbamoylating agents, for example, Fmoc-Cl and Alloc-Cl tended to give bis-protected by-products. Thus, novel microwave-assisted solid-phase N-protection procedures were developed for efficient introduction of Fmoc, Boc and Alloc groups. The subsequent cyclization proceeded in moderate to excellent yields depending on the bulk of the side chain and type of N-protecting group. This protocol readily provided novel cis- and trans-2,5-disubstituted piperazines displaying a variety of N-protecting group patterns after further on-resin manipulations. Also, unexpected by-products obtained during these optimization studies were identified and characterized. This includes nosylated ureas arising from an alternative cyclization pathway. Finally, post-cleavage oxidation gave access to the Fmoc/Boc-protected alpha-amino acid as well as the corresponding aldehyde. The chiral piperazines described in this work will enable construction of combinatorial libraries with a higher chemical diversity compared to those containing simple N,N'-difunctionalized piperazines, often present in drug-like compounds.

Discovery of potent, orally bioavailable, selective 5-HT1A/B/D receptor antagonists

5-HT1 receptor antagonists have been discovered with good selectivity over the 5-HT transporter. This is the first report of highly potent, selective ligands for the 5-HT1A/B/D receptors with low intrinsic activity, which represent a useful set of molecules for further understanding the roles of the 5-HT1 receptor subtypes and providing new approaches for the treatment of depression.

Studies on a series of potent, orally bioavailable, 5-HT1 receptor ligands

A series of 5-(piperidinylethyloxy)quinoline 5-HT(1) receptor ligands have been studied by elaboration of the series of dual 5-HT(1)-SSRIs reported previously. These new compounds display a different pharmacological profile with potent affinity across the 5-HT(1A), 5-HT(1B) and 5-HT(1D) receptors and selectivity against the serotonin transporter. Furthermore, they have improved pharmacokinetic profiles and CNS penetration.