D-Fructose derived b-amino alcohols 2 and 3 were used as organocatalysts for direct asymmetric aldol reaction of various aromatic aldehydes with three kinds of cyclic ketones in the presence of different additives as a co-catalyst. The results showed that the combinations of b-amino alcohol 2 and pnitrophenol built up a novel catalytic system. Loading of 20 mol% 2 and 15 mol% p-nitrophenol gave excellent yields (up to 98% with respect to aldehyde) of aldol reaction products with good enantioselectivity (up to 87% ee). Accordingly, a mechanism for the reaction was proposed by 1 H NMR spectrum in this paper. Furthermore, the catalysts can be reused and have the significant catalyst recovery (77-84%).
A novel ''turn-on'' fluorescent sensor based on glucose and rhodamine B for detection of mercury ions was designed and synthesized. The fluorescent sensor showed an extreme specificity for mercury ions than for other metal ions in aqueous solution. On adding mercury ions to the solution of glucose-based rhodamine B sensor, the absorption and fluorescence signals enhanced remarkably at 567 and 587 nm, respectively. Titration of sensor with mercury ions showed 1:1 stoichiometric reaction. The cyclic voltammetric measurement of an increasing amount of mercury ions in the solution of glucose-based rhodamine B sensor commendably showed the change in the fluorescence characteristics. Furthermore, the successful detection of trace amount of mercury ions in water indicated that glucose-based rhodamine B sensor can be used for the detection of the limited mercury ions in drinking water.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.