Intramolecular 1,3‐Dipolar Cycloaddition‐Mediated Stereoselective Synthesis of Disubstituted Cyclopentane: A Simple Model for the Cyclopentane Ring System of Polycyclic Oroidine Alkaloids

We present a diastereoselective synthesis of disubstituted cyclopentane 8 having a nitrogen‐containing quaternary carbon center, which is found in axinellamine A ( 5 ) and related compounds. During this work, we found that the 1,3‐dipolar cycloaddition product 24 immediately underwent intramolecular redox reaction at the newly formed morpholin‐2‐one moiety, thus affording disubstituted cyclopentane containing a tertiary amine ( 9 ) stereoselectively in good yield. The amine 9 was successfully converted into guanidine 31 , which corresponds to 8 , through iminium cation–enamine isomerization.     

Transportation of a microdroplet on an oriented liquid crystal surface

Wetting phenomena play important roles in several technological applications and in many physical and biological thin‐film phenomena, such as wetting, adhesion and friction. One of key issues of these studies is to control the surface energy (or wettability) dynamically for liquid transportation. We have developed a liquid crystal (LC) surface for use as a transport substrate since we expected that the surface energy of an LC surface can be controlled rapidly using an electric field. The rapid control of the polarisability (or wettability) of a liquid crystalline surface by an electric field has been demonstrated, together with the transportation of a liquid microdroplet.     

Synthesis of N-labeled 4-oxo-2,2,6,6-tetraethylpiperidine nitroxide for EPR brain imaging

A scalable synthetic route for ¹⁵N-labeled 4-oxo-2,2,6,6-tetraethylpiperidine nitroxide (¹⁵N-TEEPONE) is described. This ¹⁵N-labeled nitroxide is suitable for electron paramagnetic resonance imaging of brain, and its higher sensitivity compared with that of its ¹⁴N-counterpart is an important advantage of the labeled derivative.     

Synthesis of chlorophyll-a derivatives possessing (un)substituted 13-exo-methylene moiety and their optical properties

Chlorophyll-a derivatives possessing an un/mono/disubstituted methylene moiety at the 13¹-position were prepared by (un)substituted methylation of the 13-carbonyl group and successive dehydration. Substitution of the 13¹-oxo to the methylene group slightly blue-shifted electronic absorption and emission bands in a solution and decreased chemical stability to give an oxidation product cleaved at the E-ring. Further mono/disubstitution at the methylene terminal increased wavelengths of absorption and emission maxima as well as oxidative tolerance.     

Preparation of Molecule‐Responsive Microsized Hydrogels via Photopolymerization for Smart Microchannel Microvalves

Microdevices designed for practical environmental pollution monitoring need to detect specific pollutants such as dioxins. Bisphenol A (BPA) has been widely used as a monomer for the synthesis of polycarbonate and epoxy resins. However, the recent discovery of its high potential ability to disrupt human endocrine systems has made the development of smart systems and microdevices for its detection and removal necessary. Molecule‐responsive microsized hydrogels with β‐cycrodextrin (β‐CD) as ligands are prepared by photopolymerization using a fluorescence microscope. The molecule‐responsive micro‐hydrogels show ultra‐quick shrinkage in response to target BPA. Furthermore, the flow rate of a microchannel is autonomously regulated by the molecule‐responsive shrinking of their hydrogels as smart microvalves.

     

Photo-Induced Dihydroxylation of Alkenes with Diacetyl,Oxygen, and Water

Herein reported is a photo-induced production of vicinal diols from alkenes under mild reaction conditions. The present dihydroxylation method using diacetyl (= butane-2,3-dione), oxygen, and water dispenses with toxic reagents and intractable waste generation.     

Channelled Porous TiO2 Synthesized with a Water‐in‐Oil Microemulsion

Porous titanium dioxide synthesized with a bicontinuous surfactant template is a promising method that leads to a high active surface area electrode. The template used is based on a water/isooctane/dioctyl sodium sulfosuccinate salt together with lecithin. Several parameters were varied during the synthesis to understand and optimize channel formation mechanisms. The material is patterned in stacked conical channels, widening towards the centre of the grains. The active surface area increased by 116 % when the concentration of alkoxide precursors was decreased and increased by 241 % when the template formation temperature was decreased to 10 °C. Increasing the oil phase viscosity tends to widen the pore aperture, thus decreasing the overall active surface area. Changing the phase proportions alters the microemulsion integrity and disrupts channel formation.