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Updated: Jul 6, 2026

Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture
Published on: May 13, 2018
Kinetic resolution displaying zeroth order dependence on substrate consumption: copper-catalyzed asymmetric
Makoto Tokunaga1, Junya Kiyosu, Yasushi Obora
1Catalysis Research Center and Division of Chemistry, Graduate School of Science, Hokkaido University, SORST and CREST, Japan Science and Technology Agency (JST), Sapporo. tokunaga@cat.hokudai.ac.jp
Abstract:
Kinetic resolution of 4-alkyl-2-aryl-5-oxo-4,5-dihydrooxazole-4-carboxylic acid esters (azlactones 1) were achieved by copper-DTBM-SEGPHOS catalyzed alcoholysis reaction with good selectivity (12 examples). Variation of ee of unreacted substrates 1 and products 2 with conversion was found to follow the theoretical line of zeroth-order kinetic resolution, for which the selectivity profiles and graphical analysis were presented for the first time. The efficiency of resolution in zeroth-order reaction is higher than first-order reaction. For example, the reaction with 1a afforded (S)-1a (99% ee) and (R)-2a (74% ee) at 57% conversion, where the k(rel) values were calculated to be 6.7 as zeroth-order kinetic resolution and 37 as first-order kinetic resolution.
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