86195-49-5Relevant academic research and scientific papers
Synthesis of optically pure terminal epoxide and 1,2-diol via hydrolytic kinetic resolution catalyzed by new heterometallic salen complexes
Thakur, Santosh Singh,Chen, Shu-Wei,Li, Wenji,Shin, Chang-Kyo,Koo, Yoon-Mo,Kim, Geon-Joong
, p. 2371 - 2383 (2006)
The inactive chiral (salen)Co complex is easily activated by InCl 3 and TlCl3 Lewis acids by forming heterometallic salen complexes. These complexes show very high catalytic activity for the synthesis of enantiomerically enriched terminal epoxides (>99% ee) and 1,2-diols simultaneously via hydrolytic kinetic resolution. Strong synergistic effects of different Lewis acids, Co-In and Co-Tl, were exhibited in the catalytic process. The system described is very simple and efficient. Copyright Taylor & Francis Group, LLC.
Dinuclear salen cobalt complex incorporating Y(OTf)3: enhanced enantioselectivity in the hydrolytic kinetic resolution of epoxides
Patel, Deepak,Kurrey, Ganesh Ram,Shinde, Sandip S.,Kumar, Pradeep,Kim, Geon-Joong,Thakur, Santosh Singh
, p. 82699 - 82703 (2015/10/19)
The activation of inactive Jacobsen's chiral salen Co(ii) (salen = N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine) compound is attained by dinuclear chiral salen Co(iii)-OTf complex formation with yttrium triflate. The yttrium metal not only displays a promoting effect on electron transfer, but also assists in forming two stereocentres of a Lewis acid complex with Co(iii)-OTf. We found that the binuclear Co-complex significantly enhanced reactivity and enantioselectivity in the hydrolytic kinetic resolution of terminal epoxides compared to its analogous monomer and kinetic data are also consistent with these results.
Hydrolytic kinetic resolution of terminal epoxides catalyzed by novel bimetallic chiral Co (salen) complexes
Kawthekar, Rahul B.,Kim, Geon-Joong
, p. 1236 - 1248 (2008/09/18)
Novel bimetallic chiral Co (salen) complexes bearing transition-metal salts have been synthesized. The easily prepared complexes exhibited very high catalytic reactivity and enantioselectivity in hydrolytic kinetic resolution (HKR) of racemic terminal epoxides and consequently provided enantiomerically enriched epoxides (up to 99% ee). Copyright Taylor & Francis Group, LLC.
A new dinuclear chiral salen complexes for asymmetric ring opening and closing reactions: Synthesis of valuable chiral intermediates
Thakur, Santosh Singh,Chen, Shu-Wei,Li, Wenji,Shin, Chang-Kyo,Kim, Seong-Jin,Koo, Yoon-Mo,Kim, Geon-Joong
, p. 1862 - 1872 (2007/10/03)
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 terminal epoxides (>99% ee). It also catalyzes the asymmetric cyclization of ring opened product, to prepare optically pure terminal epoxides in one step. The homogeneous dinuclear chiral Co(salen) have been covalently immobilized on MCM-41. The potential benefits of heterogenization include facilitation of catalyst separation and recyclability requiring very simple techniques. The system described is very efficient.
