The enantioselective Henry reaction is a very important and useful carbon–carbon bond forming reaction. The execution of this reaction requires the use of efficient chiral catalysts. In this work, in situ formed complexes of N‐substituted dihydroxypyrrolidines, chiral ligands derived from L‐tartaric acid and amines, were evaluated as catalysts in the enantioselective Henry reaction. The results showed that the nature of the N‐substituent on the ligand significantly influences the outcome of the reaction. Best results were obtained using a Cu (II) complex of (3S,4S)‐N‐benzyl‐3,4‐dihydroxypyrrolidine, in the presence of DIPEA, for the reaction of aromatic aldehydes with nitromethane, at room temperature, originating products with er up to 92:8 (R:S) and conversions up to 96%. The interaction between the pyrrolidine ligand and the copper ion, in isopropanol, was followed by UV‐vis spectrophotometry, showing a 1:1 stoichiometry and a binding constant of 4.4. The results obtained will contribute to the design and development of more efficient chiral catalysts for this type of reaction.
Cleaning products have a global market of around $33 billion in 2020 and play an essential role in daily life, providing consumers with important public health benefits. Surfactants are the main ingredients of cleaning products and they can effectively remove dirt, germs, and other contaminants from surfaces. Understanding the role of each surfactant class in a detergent formulation and their interaction with NaCl is of utmost importance for formulating efficient and sustainable cleaning products. This paper describes the study of ternary surfactant systems consisting of surfactants (sodium lauryl ether sulfate, alkyl polyglycoside, or betaine, three of the most commonly used surfactants in detergent formulations), water, and NaCl. The effects of concentration on critical micelle concentration, aggregate size, and rheological behavior were evaluated by dynamic light scattering and rheology techniques.
Several novel chiral organocatalysts derived from thiazolidines containing amide and thioureia
functionalities were synthesized in good yields. These organocatalysts were tested in the asymmetric
aldol reaction of acetone with p-nitrobenzaldehyde. Reaction parameters such as reaction time, catalyst
loading and solvent were optimized. Products with conversions up to 84% and enantiomeric ratios
(er) up to 84.5:15.5 (R:S) were obtained. The effect of several chiral and non-chiral additives on the
reactivity and selectivity of the reaction was also evaluated. The reaction was extended to other aromatic
aldehydes with the best organocatalyst and when p-bromobenzaldehyde was used, an er of
94.5:5.5 (R:S) was obtained.
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.