Ru-Catalyzed Asymmetric Hydrogenation of 3-Oxoglutaric Acid Derivatives via Solvent-Assisted Pinpoint Recognition of Carbonyls in Close Chemical Propinquity
摘要:
Upon comparison of hydrogenation rates of various beta-ketocarboxylic acid derivatives, beta-ketoamides were found to be hydrogenated slightly faster than beta-ketoesters in EtOH in the presence of [RuCl(benzene)(S)-SunPhos]Cl at 70 degrees C with 20 bar of hydrogen. In THF these differences were so sharpened that beta-ketoamides were hydrogenated even faster than In EtOH while the esters were extremely slow. Based on these findings, a series of 3-oxoglutaric acid derived with ester and amide moieties on the two ends were hydrogenated to 3-hydroxyl products with high enantioselectivities.
Methods and intermediates for the preparation of oligomers containing diastereomerically enriched phosphorothioate linkages are disclosed.
本发明揭示了制备含有对映异构富集的磷酸硫酯键寡聚物的方法和中间体。
Method for preparing optically active beta-butyrolactones
申请人:Watanabe Shinya
公开号:US20060046286A1
公开(公告)日:2006-03-02
The present invention is to provide a method for preparing easily and efficiently β-butyrolactones and/or optically active 3-hydroxycarboxylic acid derivatives in high optical purity by use of an easily available hydrolase, which are useful as intermediates for pharmaceuticals, agrochemicals and the like. More particularly, the present invention relates to a method for preparing β-butyrolactones and/or optically active 3-hydroxycarboxylic acid derivatives with an optical purity of substantially 100% ee, comprising reacting a β-butyrolactone which is a mixture of optical isomers, with a nucleophilic agent in the presence of a hydrolase, provided that a lipase derived from porcine pancreas is excluded.