Copper-Photocatalyzed Borylation of Organic Halides under Batch and Continuous-Flow Conditions

The copper-photocatalyzed borylation of aryl, heteroaryl, vinyl and alkyl halides (I and Br) was reported. The reaction proceeded using a new heteroleptic Cu complex under irradiation with blue LEDs, giving the corresponding boronic-acid esters in good to excellent yields. The reaction was extended to continuous-flow conditions to allow an easy scale-up. The mechanism of the reaction was studied and a mechanism based on a reductive quenching (Cu^I/Cu^I*/Cu⁰) was suggested.     

Formulation of Cannabidiol in Colloidal Lipid Carriers

In this study, the general processability of cannabidiol (CBD) in colloidal lipid carriers was investigated. Due to its many pharmacological effects, the pharmaceutical use of this poorly water-soluble drug is currently under intensive research and colloidal lipid emulsions are a well-established formulation option for such lipophilic substances. To obtain a better understanding of the formulability of CBD in lipid emulsions, different aspects of CBD loading and its interaction with the emulsion droplets were investigated. Very high drug loads (>40% related to lipid content) could be achieved in emulsions of medium chain triglycerides, rapeseed oil, soybean oil and trimyristin. The maximum CBD load depended on the type of lipid matrix. CBD loading increased the particle size and the density of the lipid matrix. The loading capacity of a trimyristin emulsion for CBD was superior to that of a suspension of solid lipid nanoparticles based on trimyristin (69% vs. 30% related to the lipid matrix). In addition to its localization within the lipid core of the emulsion droplets, cannabidiol was associated with the droplet interface to a remarkable extent. According to a stress test, CBD destabilized the emulsions, with phospholipid-stabilized emulsions being more stable than poloxamer-stabilized ones. Furthermore, it was possible to produce emulsions with pure CBD as the dispersed phase, since CBD demonstrated such a pronounced supercooling tendency that it did not recrystallize, even if cooled to −60 °C.     

CATALYSE INTRAMOLECULAIRE DE L'AMINOLYSE DES HETEROCYCLES PHOSPHORES DERIVES DES α AMINOAMIDES. II: ETUDE DE LA CYCLISATION DES PHOSPHORDIAMIDES INCORPORANT UN RESIDU DE β AMINOACIDE,REACTIVITE VIS A VIS DE NUCLEOPHILES DES HETEROCYCLES FORMES

Abstract

Derivatives of β aminoacids in form of esters 1 or nitrile 4 (table I) undergo in an alcohol-ate/alcohol medium a rearrangement (Fig. 2), with formation of a β peptide link, resulting in the formation of esters 6 (table II). According to the experimental conditions the six membered ring heterocycles 5 are detected or isolated. They are also synthetized by cyclisation of acids 2 or hydrazide 3 (Fig. 5). While phosphorus easily reacts with alcohols and water, leading respectively to esters 6 and acids 9 (Fig. 7), it remains unaffected by amines. These results are discussed in term of mechanisms of the phosphorylation. The applications for β peptide synthesis and the participation of the p amide group in phosphorylation are limited.     

CdS and Cd carboxylate nanoclusters dispersed in polymer matrix produced by a freeze drying method

Cadmium sulfide (CdS) nanoclusters were prepared by a freeze drying method from two types of cadmium carboxylates. One was cadmium methacrylates that were part of poly(methyl methacrylate) (PMMA) ionomer. The other was cadmium acetates that were dispersed in PMMA. X-ray diffraction was mainly used to study the formation and the size of nanoclusters. The size of CdS made from the ionomer was 0.9 nm, whereas that from the composite of cadmium acetate and PMMA was 2 nm. This was consistent with the size difference of the precursors of CdS: i.e., Cd carboxylate nanoclusters (ionic aggregates) were smaller in the ionomer than in the PMMA mixture, because ionic groups in the ionomer were constrained due to their connectivity to backbone chains and thus forming smaller ionic aggregates. Once stabilized, however, CdS nanocluster sizes were unchanged despite thermal treatments at up to 220 °C for 24 h for both systems. Structural transformations from a freeze dried cadmium carboxylate powder, to a CdS-containing powder, and to a heat-treated CdS-containing sample are speculated for both types of systems.     

A Convenient Synthesis of (S)-(+)-2-(2-Methoxyphenyl) Propanoic Acid

a short, convenient and large scale synthesis of (S)-(+)-2-(2-methoxyphenyl) propanoic acid, involving a resolution of the corresponding racemic acid with quinine, is reported.     

Liquid crystal polysiloxane networks as materials for molecular imprinting technology: memory of the mesomorphic organization

A novel approach to the synthesis of molecularly imprinted polymers via non-covalent linkages has been studied. It relies on the use of thermotropic side group liquid crystal polymer networks. The polysiloxane networks obtained after extraction of the template preserved the mesomorphic organization set up in the presence of the guest molecule. A first batch rebinding analysis was performed: this study revealed that the imprinted polymer has a much greater affinity for the template molecule than has the non-imprinted polymer, and a significant selectivity.     

High Speed Video Camera and Electrical Signal Analyses of Arcs Behavior in a 3-Phase AC Arc Plasma Torch

A 3-phase AC plasma torch has been developed and aims at overcoming some limits of the classical DC torches in terms of efficiency, cost and reliability. However, the arc behavior in 3-phase plasma torch remains poorly explored. This paper is dedicated to the high speed video camera at 100,000 frames per second and electrical signal analyses of arcs behavior in a 3-phase AC arc plasma torch. First, a reference case at 150 A, in nitrogen as working gas, has been deeply analyzed. Afterwards, a parametric study based on current and inter-electrode gap has been carried out. Results show that only one arc can exist at a given time and arcs rotate by switching from a pair of electrodes to another one, following the maximal electrical gap potential. However, a particular “abnormal” arc behavior was sometimes observed. Indeed, the arc motion within the inter-electrode gap increases the heat exchange and stabilizes the 3-phase discharge whereas the system is unbalanced when the arc is in the periphery. The analysis highlights that the arc motion is strongly influenced by the electrode jet velocity and repulsive Lorentz forces. The parametric study shows that the current increases both jet velocity and arc discharge stability. Elsewhere, the increase of the inter-electrode gap can also stabilizes the electrical 3-phase arc discharge. Furthermore, the correlation between arc motion and current waveform is highlighted. This work is likely to open the way toward a better understanding of 3-phase discharges in the perspective of their further optimization.