Exploring the distribution and fate of bisphenol A in an aquatic microcosm combined with a multimedia model.

Bisphenol A (BPA), a well-known endocrine-disrupting chemical, has garnered significant attention in environmental science and policy. BPA can enter the aquatic environment through different routes, posing potential risks even at a low concentration. In this study, a four-compartment system [water, sediment, biota (zebrafish), and submerged aquatic vegetation (Vallisneria natans)] of a point source continuous discharge microcosm was established to investigate the distribution and fate of BPA in an aquatic microcosm.

Review and test on rare earths recovery from polishing powder waste.

Rare earth polishing powder has gained widespread usage in the surface polishing of high-precision materials, exhibiting an annual growth rate exceeding 10 %. However, a significant portion of this powder is discarded due to impurities and the need for particle size refinement. The waste generated from polishing powder contains 10.

Dynamic kinetic resolution of azlactones catalyzed by chiral Brønsted acids.

Chiral Brønsted acids have been shown for the first time to catalyze the dynamic kinetic resolution of azlactones. 3,3'-Bis-(9-anthryl)-BINOL phosphoric acid 3c is particularly effective in the case of 4-aryl-substituted substrates, producing 85-92% ee's.

Benzotetramisole-catalyzed dynamic kinetic resolution of azlactones.

Enantioselective acyl transfer catalyst benzotetramisole (BTM) has been found to promote dynamic kinetic resolution of azlactones providing di(1-naphthyl)methyl esters of alpha-amino acids with up to 96% ee.

Selective oxidation of polyfunctional 2-amino-1,3-propanediol derivatives.

Oxidation of polyfunctional threo-(1S,2S)-2-amino-1,3-propanediol derivatives with a 717 anion-exchange resin-supported bromine has been investigated. The result showed that oxidized products were in close relationship with the substituents at nitrogen in the starting materials. Its primary and secondary amine derivatives were oxidized in the presence of Na(2)HPO(4) to give essentially a substituted chiral oxazoline or C(3)-O acylated product in high yield, while oxidation of its N,N-dimethyl derivative mainly gave a chiral N-methyl oxidation-formylation product.