Photosensitive Polyarylates Based on Reaction Development Patterning

Films of a commercially available polyarylate (U polymer®) containing a photosensitive agent were prepared by means of spin‐coating onto copper foil, which showed positive‐tone behavior after UV irradiation and development with an ethanolamine/N‐methylpyrrolidone/H₂O mixture. Scanning electron microscope photographs of the images exhibited fine patterns (≈10 μm line/space resolution) with 9–14 μm film thickness. The pattern‐forming mechanism is based on the reaction development patterning (RDP) process, where the main pattern‐forming reaction occurs during development.     

Asymmetric Polymer Synthesis by Repetitive Sakurai–Hosomi Allylation Reaction of Compounds Possessing Both Formyl and Allylsilane Functions

Trialkylallylsilanes generally react with aldehydes in the presence of a Lewis acid to the corresponding homoallylic alcohols. Chiral Lewis acids promote the same reaction to yield the enantiomerically‐enriched homoallylalcohols. We have prepared four compounds ( 7 – 10 ) that possess both formyl and allylsilane functions. Lewis acids initiated self‐polyaddition reactions of these compounds by means of repetitive allylation. The use of chiral Lewis acids resulted in the formation of optically active polymers that possess exo‐methylene and secondary OH functions in their main chain. The optical purity of these chiral polymers was estimated based on the results of model asymmetric reactions between benzaldehyde and β‐substituted allylsilanes and by controlled degradation.     

Ordered structures of poly(1H,1H,2H,2H-perfluorodecyl α-substituted acrylate)S

Ordered structures of poly(1H,1H,2H,2H-perfluorodecyl α-fluoroacrylate) (P17FF), poly(α-chloroacrylate) (P17FC), poly(methacrylate) (P17FM) and poly(acrylate) (P17FA) were investigated by X-ray diffraction, DSC and polarizing microscopic observations. At room temperature, both P17FF and P17FC prefer the layered structure of single-layer packing of the fluoroalkyl side chains, while P17FM contains both single-layer and double-layer packing, and P17FA forms double-layer packing. As temperature increases, particularly in P17FF and P17FC, there was observed a structural rearrangement of the single-layer packing to double-layer one accompanied by melting of the side chain crystallites, which may come from an intermolecular interaction between the main chains caused by polar effect of the α-substituents.     

A Simple and Effective Way to Integrate Nile Blue Covalently onto Functionalized SWCNTs Modified GC Electrodes for Sensitive and Selective Electroanalysis of NADH

A simple and new way to assemble Nile blue (NB) covalently onto the surface of functionalized single‐walled carbon nanotubes (f‐SWCNTs) modified glassy carbon (GC) electrode (NB/f‐SWCNTs/GC electrode) was described. The NB/f‐SWCNTs/GC electrode catalyzes effectively the oxidation of NADH with a remarkably decreased overpotential (ca. 700 mV) compared with that at the bare GC. The reaction was found to obey a so‐called Michaelis–Menten kinetics and the related kinetic parameters were determined. This modified electrode possesses promising characteristics as NADH sensor; a wide linear dynamic range of 0.2 to 200 µM, low detection limit of 0.18 µM, fast response time (1–2 s), high sensitivity (24 µA cm⁻² mM⁻¹), anti‐interference ability and anti‐fouling.     

Temperature effect on the recovery of SO2-Poisoned GC/Nano-Pt electrode towards oxygen reduction

The SO₂ poisoning of Pt nanoparticle (n-Pt) modified glassy carbon (GC/n-Pt) electrode and the recovery of its activity for the oxygen reduction reaction (ORR) were studied using cyclic voltammetry at ambient (25 °C) and elevated (70 °C) temperatures. Recovery of the GC/n-Pt electrode by cycling the potential within the ORR range (1.0 to 0.2 V (standard hydrogen electrode)) in 0.1 M H₂SO₄ was not effective at 25 °C, but at 70 °C the onset potential of the ORR was almost the same as that at the fresh GC/n-Pt electrode. For the two different temperatures used here, the recovery on cycling the potential between 0.4 and 1.7 V was efficient. However, the number of cycles and the amount of charge required for the recovery at 70 °C were the smallest, which is of great interest for the proton exchange membrane fuel cell performance. The recovery using such a wide potential range at 70 °C resulted in an enhancement of the electrocatalytic activity of the GC/n-Pt electrode over a non-poisoned (bare) GC/n-Pt electrode.     

The Pharmacological Potential of Adenosine A2A Receptor Antagonists for Treating Parkinson’s Disease

The adenosine A_2A receptor subtype is recognized as a non-dopaminergic pharmacological target for the treatment of neurodegenerative disorders, notably Parkinson’s disease (PD). The selective A_2A receptor antagonist istradefylline is approved in the US and Japan as an adjunctive treatment to levodopa/decarboxylase inhibitors in adults with PD experiencing OFF episodes or a wearing-off phenomenon; however, the full potential of this drug class remains to be explored. In this article, we review the pharmacology of adenosine A_2A receptor antagonists from the perspective of the treatment of both motor and non-motor symptoms of PD and their potential for disease modification.     

Synthesis of Novel Polymers with a Chiral 1,2-Diamine Moiety by Polycondensation and their Application to Catalyst for Asymmetric Hydrogenation of Aromatic Ketones

Summary: Novel polymers with chiral 1,2-diamine moiety were successfully synthesized by polycondensation of N-Boc protected enantiopure 1,2-diamine bearing two phenol groups ( S , S )-4 , bisphenol derivatives, and dibromides, followed by deprotection of N-Boc moiety. Hydrogenation of acetophenone was performed with use of polymeric catalyst system prepared from the polymer-supported chiral 1,2-diamine and RuCl₂/(S)-BINAP. The reaction proceeded smoothly even in 2-propanol to give 1-phenylethanol in quantitative yield with high level of enantioselectivity. Furthermore, various other aromatic ketones could be asymmetrically hydrogenated by the polymeric catalyst system.