Catalyst-Free Synthesis of Alkylpolyglycosides Induced by High-Frequency Ultrasound

Like Visiting an Old Friend: Fischer Glycosylation in the Twenty-First Century: Modern Methods and Techniques

Fischer glycosylation is typically the chemical reaction of a monosaccharide and an alcohol in presence of an acidic catalyst to afford glycosides in pyranosidic and furanosidic forms. This reaction is still applied today for the synthesis of specialized glycosides, and optimization and modification of the method have continued since its discovery by Emil Fischer in the 1890s. This review presents advancements in Fischer glycosylation described in literature of the past 15 years and its implementation in modern chemical methods.

Hydrogen from Water is more than a Fuel: Hydrogenations and Hydrodeoxygenations for a Biobased Economy

Worldwide a hydrogen-based economy is on the political agenda. Its centre forms molecular hydrogen (H₂ ) that should serve mainly as energy carrier and fuel. However, currently and foreseeable in the future H₂ is playing its main role as reactant in the chemical industry. Electrolytic generation and storage of H₂ gas is energy demanding and may hardly become economically at the large scale. We argue that in the overall transition towards an economy that is based on biomolecules and CO₂ as carbon feedstock electrochemical hydrogenations and hydrodeoxygenations in aqueous solutions need to be moved in the centre. Departing from the well-known fact that electrochemistry allows creating reactive hydrogen species from water, i. e. hydrogen in statu nascendi (H^. ), at ambient temperature and pressure we illustrate the existing diversity of reactions based thereon. We focus on examples of model compounds from thermal biomass pretreatment and products from real thermal biomass pretreatment (bio-oil). Consequently, we advocate that electrochemical hydrogenations and hydrodeoxygenations have to be further explored and interweaved into existing process lines.

Sonochemical fabrication of inorganic nanoparticles for applications in catalysis

Catalysis covers almost all the chemical reactions or processes aiming for many applications. Sonochemistry has emerged in designing and developing the synthesis of nano-structured materials, and the latest progress mainly focuses on the synthetic strategies, product properties as well as catalytic applications. This current review simply presents the sonochemical effects under ultrasound irradiation, roughly describes the ultrasound-synthesized inorganic nano-materials, and highlights the sonochemistry applications in the inorganics-based catalysis processes including reduction, oxidation, degradation, polymerization, etc. Or all in all, the review hopes to provide an integrated understanding of sonochemistry, emphasize the great significance of ultrasound-assisted synthesis in structured materials as a unique strategy, and broaden the updated applications of ultrasound irradiation in the catalysis fields.

A Highly Effective Route to Si-O-Si Moieties through O-Silylation of Silanols and Polyhedral Oligomeric Silsesquioxane Silanols with Disilazanes

A simple and highly practical catalyst-free O-silylation of silanols with commercially available disilazanes has been developed under mild conditions. In the case of polyhedral oligomeric silsesquioxane (POSS) silanols and some other silanols, it was necessary to use catalytic amounts of inexpensive Bi(OTf)₃ as additional catalyst. This efficient chlorine-free protocol involves the synthesis of a wide range of important organosilicon derivatives such as unsymmetrical disiloxanes and functionalized silsesquioxanes.