10031-86-4Relevant articles and documents
Shell Cross-Linked Micelles as Nanoreactors for Enantioselective Three-Step Tandem Catalysis
Kuepfert, Michael,Cohen, Aaron E.,Cullen, Olivia,Weck, Marcus
, p. 18648 - 18652 (2018)
Functionalized amphiphilic poly(2-oxazoline)-based triblock copolymers that assemble into shell cross-linked micelles (SCMs) are described. These micelles permit the site isolation of three incompatible catalysts through compartmentalization, thereby enabling three-step non-orthogonal tandem processes in one pot. In particular, the acid-catalyzed ketal hydrolysis to prochiral ketones proceeded in the hydrophilic corona, followed by the Rh-catalyzed asymmetric transfer hydrogenation to enantio-enriched alcohols in the cross-linked shell, and nucleophilic base-catalyzed acylation in the hydrophobic core. The catalysts are positioned in close proximity on a single micelle support to take advantage of the intramicellar substrate diffusion, yet they are sufficiently spaced apart from each other in physically distinct microenvironments. These compartmentalized micelles are substrate selective and, on a basic level, mimic compartmentalized catalytic architectures found in nature.
Improved Enantioselectivity of Subtilisin Carlsberg towards Secondary Alcohols by Protein Engineering
Dorau, Robin,G?rbe, Tamás,Svedendahl Humble, Maria
, p. 338 - 346 (2017/12/26)
Generally, the catalytic activity of subtilisin Carlsberg (SC) for transacylation reactions with secondary alcohols in organic solvent is low. Enzyme immobilization and protein engineering was performed to improve the enantioselectivity of SC towards secondary alcohols. Possible amino-acid residues for mutagenesis were found by combining available literature data with molecular modeling. SC variants were created by site-directed mutagenesis and were evaluated for a model transacylation reaction containing 1-phenylethanol in THF. Variants showing high E values (>100) were found. However, the conversions were still low. A second mutation was made, and both the E values and conversions were increased. Relative to that shown by the wild type, the most successful variant, G165L/M221F, showed increased conversion (up to 36 %), enantioselectivity (E values up to 400), substrate scope, and stability in THF.
Molecular recognition driven catalysis using polymeric nanoreactors
Cotanda, Pepa,O'Reilly, Rachel K.
supporting information, p. 10280 - 10282,3 (2020/09/09)
The concept of using polymeric micelles to catalyze organic reactions in water is presented and compared to surfactant based micelles in the context of molecular recognition. We report for the first time enzyme-like specific catalysis by tethering the catalyst in the well-defined hydrophobic core of a polymeric micelle.
