The secretion from the hippopotamus’ skin changes its color from colorless to red, and then brown by polymerization of its pigments. The responsible pigments for the coloring reaction were isolated and denoted as hipposudoric acid (the red pigment) and norhipposudoric acid (the orange pigment). The syntheses of these pigments and the related derivatives were performed, and the latter were of us...

The synthesis of polyimides (PIs) containing polydimethylsiloxane (PDMS) with controlled chain length and the formation higher-order structures were studied. Polycondensation was carried out using diphenyl-3,3',4,4'-tetracarboxylic dianhydride (BPDA) diamine oligomers having amino groups on both ends PDMS. obtained poly(amic acid) (PAA) PI showed good solubility in several common polar solvents...

A triple cascade was developed using a simple copper catalyst to trans-selectively access bicyclic isoxazolidines in a one-pot synthesis. This strategy features the in situ generation of nitrones and subsequent trapping by [3 + 2] cycloaddition. In this method, copper serves three catalytic functions: as a Lewis acid for the ene reaction, as an organometallic for aerobic oxidation, and as a Lew...

Solution phase titrations are made easy by multi-nuclear FlowNMR spectroscopy with automated, continuous titre addition to give accurate insights into Brønsted acid/base, hydrogen bonding, Lewis acid/base and metal/ligand binding equilibria under native conditions.

Reactions carried out both in protic and aprotic water-miscible solvents can be affected by the presence of water. We have recently discovered that luminescence intensity a methanolic solution Tb(III) containing salicylic acid Tb�SA is highly sensitive to water content. The water-induced quenching was utilized for accurate measurement content methanol, ethanol, acetonitrile, tetrahydrofuran 0...

An efficient synthesis of a valuable intermediate of coenzyme Q(10) by microwave-assisted Lewis acidic ionic liquid (IL)-catalyzed Friedel-Crafts alkylation is reported. The acidity of six [Etpy]BF(4)-based ionic liquids was characterized by means of the FT-IR technique using acetonitrile as a molecular probe. The catalytic activities of these ionic liquids were correlated with their Lewis acid...

N-methylol compounds, such as dimethyloldihydroxyethyleneurea (DMDHEU), are the most commonly used durable press finishing agents for cotton fabrics. Polyfunctional carboxylic acids are becoming important as non-formaldehyde replacements for these N-methylol reactants. The use of both chemistries has been shown to cause an irreversible reduction in the physical properties of finished fabric, be...

One possible way to take advantage of such abilities may be to apply a ‘combined acids system’ [2] to the catalyst design. The concept of combined acids, which can be classified into Brønsted acid-assisted Lewis acid (BLA), Lewis acid-assisted Lewis acid (LLA), Lewis acid-assisted Brønsted acid (LBA), and Brønsted acid-assisted Brønsted acid (BBA), can be a particularly useful tool for the desi...

Cationic zirconocene or hafnocene complexes serve as a novel class of Lewis acid with unique reactivities, which are to be exploited in organic synthesis. Four categories of reactivities are discussed, that is, (A) C-F bond activation/cleavage, (B) Coordinative activation of ether linkages, (C) Carbonyl activation, and (D) C-0 bond cleavage via zirconocene alkoxide. Introduction Lewis acid-prom...