Highly Enantioselective Catalytic Vinylogous Propargylation of Coumarins Yields a Class of Autophagy Inhibitors

A highly enantioselective copper-catalyzed vinylogous propargylic substitution has been developed. Aromatic and aliphatic propargylic esters react smoothly with substituted coumarins under mild reaction conditions to give the desired products with excellent yields and enantioselectivities. Subsequent single-step transformations enable the synthesis of a wide range of multifunctional and diverse compounds, and allow the efficient combination of different natural product fragments. Investigation of the obtained compound collection in cell-based assays monitoring changes in phenotype led to the discovery of a novel class of autophagy inhibitors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Highly Enantioselective Catalytic Vinylogous Propargylation of Coumarins Yields a Class of Autophagy Inhibitors

A highly enantioselective copper-catalyzed vinylogous propargylic substitution has been developed. Aromatic and aliphatic propargylic esters react smoothly with substituted coumarins under mild reaction conditions to give the desired products with excellent yields and enantioselectivities. Subsequent single-step transformations enable the synthesis of a wide range of multifunctional and diverse compounds, and allow the efficient combination of different natural product fragments. Investigation of the obtained compound collection in cell-based assays monitoring changes in phenotype led to the discovery of a novel class of autophagy inhibitors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Solid state 13C NMR spectroscopy provides direct evidence for reaction between ethinyl estradiol and a silicone elastomer vaginal ring drug delivery system

Steroid molecules have a long history of incorporation into silicone elastomer materials for controlled release drug delivery applications. Previously, based on in vitro release testing and drug content analysis, we demonstrated indirectly that the contraceptive progestin levonorgestrel (LNG) chemically and irreversibly binds to addition cure silicone elastomers, presumably via a hydrosilylation reaction between the levonorgestrel ethynyl group and the hydrosilane groups in the poly(dimethylsiloxane-co-methylhydrosiloxane) crosslinker of the silicone elastomer. Here, for the first time, we report that solid state ^13C nuclear magnetic resonance (NMR) spectroscopy provides direct evidence for the irreversible binding of ethinyl estradiol (EE) – an estrogenic steroid molecule also containing an ethynyl functional group – to an addition cure silicone elastomer. By preparing silicone elastomer samples containing ^13C-labelled EE, signals in the NMR spectra could readily be assigned to both the free and bound EE. Additional depolymerisation studies, performed on an addition cure silicone elastomer system from which the unbound EE fraction was completely extracted, further confirmed the presence of bound EE through the formation of coloured reaction mixtures resulting from the reaction of bound EE and trifluoroacetic acid (TFA). These methods will be particularly useful in the ongoing development of new steroid-releasing silicone drug delivery devices, including various vaginal ring devices for contraception, HIV prevention and multipurpose prevention technology applications

Correlating the Synthesis, Structure, and Catalytic Performance of Pt–Re/TiO 2 for the Aqueous-Phase Hydrogenation of Carboxylic Acid Derivatives

Pt–Re bimetallic catalysts have many applications, ranging from catalytic reforming to the reduction of carboxylic acid derivatives. However, the exact role of Re in these systems has remained a matter of discussion, partly due to the plethora of suggested synthesis protocols and analysis conditions. This study presents an extensive comparison of such literature protocols and the resulting materials. In detail, characterization by N2 physisorption, X-ray diffraction, temperature-programmed reduction, CO pulse chemisorption, Fourier-transform infrared spectroscopy of adsorbed CO, scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy, and in situ X-ray photoelectron spectroscopy is combined with catalytic testing to yield synthesis–structure–activity correlations. Accordingly, the investigated catalysts share common features, such as Pt0 nanoparticles (1–4 nm) decorated with partially reduced Re species (ReOx-y). The remaining rhenium oxide is spread over the TiO2 support and enhances Pt dispersion in sequential impregnation protocols. While differences in the number of active sites (Pt0/ReOx–y) mostly explain catalytic results, small variations in the extent of Re reduction and site composition cause additional modulations. The optimal bimetallic catalyst outperforms Ru/C (previous benchmark) in the reduction of N-(2-hydroxyethyl)succinimide, an important step in the production of a bio-based polyvinylpyrrolidone polymer

Conceptual design of an amphibious e-tricycle

The lack of sustainable public transport, heavy traffic, and floods are some of the major problems that the Philippines are experiencing throughout the years. Fossil fuel is a limited source of energy and it contributes to the destruction of the ecosystem, which is why more sustainable alternatives are needed. In addition, heavy traffic makes it difficult for people to travel around the metro that eventually affects productivity, efficiency and causes unnecessary stress and sickness. Flooding has also claimed the lives of many people; some have died because they have drowned or because of the strong current of the flood, while some died due to slow response of rescuers because of extremely inaccessible paths. The research revolves around conceptualizing a three-wheeled electric vehicle with amphibious characteristics (waterproof electric motor, sealed body) to tackle the problems discussed earlier. A vehicle that will not be heavy on the budget which will make it accessible to most people; the problem with most amphibious or electric vehicles that exists today is that the features or specifications, or simply the build, is extremely high-tech and thus expensive and scarce. It will serve as a multipurpose vehicle for public utility/transportation, recreation, and or for emergency and rescue operations. The group believes that electricity is a better alternative than fossil fuels n consideration to climate change mitigation and adaptation. In addition, focusing on public transport that will carry multiple passengers would hopefully reduce current traffic and emissions