Chiral and stable isotope analysis of synthetic cathinones

In the past decade synthetic cathinones have appeared in drug markets worldwide. Chiral analysis can provide information on relative enantiomeric abundances of synthetic cathinones in their drug products, potentially giving a signature of these products and hence linking the products or excluding them from possible sources. Additionally, due to natural variations of relative stable isotopic abundances of elements, stable isotope analysis of synthetic cathinone drug products provides the stable isotopic signature of the products and hence also has potential to provide additional information for the purpose of drug intelligence. Therefore, both molecular (chirality) and physicochemical (relative stable isotopic abundances) properties are important for forensic chemists to investigate. Chiral and isotope ratio mass spectrometric analysis are becoming increasingly important to forensic chemists and therefore this review will focus on an overview of these techniques applied to the synthetic cathinones

Asymmetric Hydrogenation in Water by a Rhodium Complex of Sulfonated 2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl (binap)

The synthesis of sulfonated 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (binap) is reported; a rhodium complex of this ligand is the first to perform asymmetric hydrogenation in neat water with optical yields as high as those obtained in nonaqueous solvent

Organocatalytic synthesis of axially chiral atropisomers

This review summarises the recent progress made in the organocatalytic synthesis of atropisomeric compounds. Methodologies based on dynamic kinetic resolution and direct access to BINOL-like biaryls are described. A particular emphasis is given to reaction mechanisms and to the development of strategies to obtain stable products by increasing the barrier to atropisomer interconversion during the reaction

Strategies towards chiral molecular conductors

Introduction of chirality into conducting systems is a topic of much current interest as it allows the preparation of multifunctional materials in which the chirality may modulate the structural disorder or expresses its influence through the electrical magneto-chiral anisotropy effect. The access to various chiral electroactive precursors for molecular conductors is therefore of paramount importance. Different families of chiral tetrathiafulvalene (TTF) derivatives are reviewed together with the corresponding synthetic strategies. Systems based on stereogenic carbon or sulfur atoms, axial and supramolecular chirality have been developed. In other systems the use of achiral TTFs with chiral anions have provided molecular conductors, although in most of them to date the anion is present in racemic form. Starting from some of these precursors several chiral conductors have been prepared and in two cases, involving either chiral TTF-oxazolines salts or BEDT-TTF salts with metal-oxalate anions and chiral solvent molecules, differences between the conductivity of the racemic and enantiopure forms have been found, as a consequence of the structural disorder in the solid state. Further developments in this field are expected to be directed especially towards helical architectures, possibly based on supramolecular chirality, and systems combining conductivity, magnetism and chirality in both organic and inorganic lattices

Influence of Phosphoramidites in Copper-Catalyzed Conjugate Borylation Reaction

Copper(I) has become the preferred metal to catalyze the β-boration of α,β-unsaturated carbonyl compounds, and now we demonstrate that easily accessible monodentate chiral ligands, such as phosphoramidites and phosphites, can be convenient alternative ligands to induce asymmetry in the enantioselective version of this reaction, particularly in the β-boration of α,β-unsaturated imines.

Synthesis of 1,1\u27-binaphthyl derivatives via benzannulated enyne-allenes

The generation of benzannulated enyne-allenes in situ via a prototropic isomerization promotes a cascade radical cyclization to the formation of 1,1 \u27-binaphthyl derivatives. The simplicity of the synthetic method and the mildness of the reaction conditions make this cascade cyclization process an intriguing alternative route to the generation of 1,1\u27 -binaphthyl derivatives. The transformation from a precursor benzannulated enyne-allene to a novel binaphthyl system proceeds through a C2-C 6 cyclization reaction followed by a radical-radical coupling reaction and tautomerization to provide the formal Diels-Alder adduct

A Chiral, Dendralenic C–H Acid

We report the synthesis of a chiral dendralenic C–H acid, which contains three unsubstituted binaphthyl moieties. This motif and an achiral variant can be made from their corresponding bis(sulfone) precursors in one step. Despite the presence of the enantiopure binaphthyl backbone, the newly designed chiral C–H acid showed only poor enantioselectivity in a Mukaiyama aldol reaction. First attempts toward the synthesis of 3,3′-hexasubstituted binaphthyl-based dendralenic acids are also reported