Synthesis of optically active 2-hydroxy monoesters via-kinetic resolution and asymmetric cyclization catalyzed by heterometallic chiral (salen) Co complex
作者:Wenji Li、Santosh Singh Thakur、Shu-Wei Chen、Chang-Kyo Shin、Rahul B. Kawthekar、Geon-Joong Kim
DOI:10.1016/j.tetlet.2006.03.042
日期:2006.5
The binuclear chiral (salen) Co complexes bearing Lewis acids of Al and Ga catalyze regio- and enantioselective ring opening of terminal epoxides with carboxylic acids. The ring opened product of epichlorohydrin with carboxylic acids followed by cyclization step in the presence of catalyst and base represent straightforward, efficient methods for the synthesis of enatiomerically enriched (>99% ee)
A new dinuclear chiral salen complexes for asymmetric ring opening and closing reactions: Synthesis of valuable chiral intermediates
作者:Santosh Singh Thakur、Shu-Wei Chen、Wenji Li、Chang-Kyo Shin、Seong-Jin Kim、Yoon-Mo Koo、Geon-Joong Kim
DOI:10.1016/j.jorganchem.2005.12.044
日期:2006.4
A new dinuclear chiral Co(salen) complexes bearing group 13 metals have been synthesized and characterized. The easily prepared complexes exhibited very high catalytic reactivity and enantioselectivity for the asymmetric ring opening of epoxides with H2O, chloride ions and carboxylic acids and consequently provide enantiomerically enriched terminalepoxides (>99% ee). It also catalyzes the asymmetric