Highly Active Oligomeric (salen)Co Catalysts for Asymmetric Epoxide Ring-Opening Reactions
作者:Joseph M. Ready、Eric N. Jacobsen
DOI:10.1021/ja005867b
日期:2001.3.1
nucleophile. In this mechanistic context, complexes that contain multiple metal centers in appropriate relative proximity and orientation can provide improved reactivity relative to monometallic catalysts. For example, chiral metal salencomplexes such as 1 are effective catalysts for asymmetric epoxide ringopening reactions, and operate by a second-order mechanism.2 Linking these catalysts as dimers3 or to
Highly active oligomeric Co(salen) catalysts for the asymmetric synthesis of α-aryloxy or α-alkoxy alcohols via kinetic resolution of terminal epoxides
作者:Xunjin Zhu、Krishnan Venkatasubbaiah、Marcus Weck、Christopher W. Jones
DOI:10.1016/j.molcata.2010.06.015
日期:2010.8.17
alcohols. The catalyst is compared to other dimeric, oligomeric and monomeric Co(salen) complexes including a pimelate-linked macrocyclic Co(salen) catalyst and a dimeric Co(salen) catalyst referred to as a bisalen. The catalysts that contain multiple Co(salen) units within a single molecular framework allow for substantial decreases in catalyst loading compared with the monomeric catalyst. The cyclooctene-based