881538-10-9Relevant articles and documents
Modular approach for the development of supported, monofunctionalized, salen catalysts
Holbach, Michael,Weck, Marcus
, p. 1825 - 1836 (2006)
We report a modular approach toward polymer-supported, metalated, salen catalysts. This strategy is based on the synthesis of monofunctionalized Mn- and Co-salen complexes attached to a norbornene monomer via a stable phenylene-acetylene linker. The resulting functionalized monomers can be polymerized in a controlled fashion using ring-opening metathesis polymerization. This polymerization method allows for the synthesis of copolymers, resulting in an unprecedented control over the catalyst density and catalytic-site isolation. The obtained polymeric manganese and cobalt complexes were successfully used as supported catalysts for the asymmetric epoxidation of olefins and the hydrolytic kinetic resolution of epoxides. All polymeric catalysts showed outstanding catalytic activities and selectivities comparable to the original catalysts reported by Jacobsen. Moreover, the copolymer-supported catalysts are more active and selective than their homopolymer analogues, providing further proof that catalyst density and site isolation are key toward highly active and selective supported salen catalysts.
Chiral linear polymers bonded alternatively with salen and 1,4-dialkoxy-2,6-diethynylbenzene: synthesis and application to diethylzinc addition to aldehydes
Jammi, Suribabu,Rout, Laxmidhar,Punniyamurthy, Tharmalingam
, p. 2016 - 2020 (2008/02/11)
The synthesis of chiral polymers 1 bonded alternatively with salen and 1,4-dialkoxy-2,6-diethynylbenzene was accomplished. These polymers are recyclable and catalyze the Et2Zn addition to aldehydes with good enantioselectivity.