novel polymer-supported thioesters were prepared and found to be effective catalysts for the enantioselective addition of diethylzinc to benzaldehyde. These catalysts gave 1-phenylpropanol in up to 86% ee. The catalysts were fully recyclable and could be used in subsequent additions with retention of the enantioselectivity and efficiency levels.
制备了一系列新型聚合物负载的硫酯,发现它们是二乙基锌与苯甲醛对映选择性加成的有效催化剂。这些催化剂产生高达 86% ee 的 1-苯基丙醇。催化剂是完全可回收的,可用于后续添加,同时保持对映选择性和效率水平。
Penem derivatives and antimicrobial agent containing the same
申请人:Ishiguro Masaji
公开号:US20050004092A1
公开(公告)日:2005-01-06
A penem derivative represented by the following formula (I):
wherein R
1
represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted alkenylthio group, a substituted or unsubstituted aralkylthio group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted heterocyclic thio group, a substituted or unsubstituted acylthio group, a mercapto group or a hydrogen atom, and R
2
represents a hydrogen atom or a carboxyl-protecting group; or a pharmacologically acceptable salt thereof.
The compound (I) exhibits strong antibacterial activities, and especially, shows strong activities against MRSA. It is therefore useful not only as a general antibacterial agent but also as an antibacterial agent for MRSA against which no general antibacterial agents are recognized to be-effective.