Cooperative Asymmetric Catalysis with Dendrimeric [Co(salen)] Complexes

Abstract

Dendrimeric catalysts can present catalytic units in close proximity, thereby inducing useful cooperative effects (see picture). Commercial dendrimers were derivatized with chiral [Co(salen)] complexes and found to display enhanced reactivity relative to monomeric or even dimeric analogues in the hydrolytic kinetic resolution of epoxides.

Biocatalysis as an alternative for the production of chiral epoxides: A comparative review

“…A broad spectrum of racemic terminal epoxides bearing a wide range of functional groups can afford the corresponding chiral epoxides with >99% ee through this process [139]. The application of oligomeric Co(salen) catalyst system can further increase the reactivity to up to 50-fold per Co(salen) unit basis [140][141][142][143][144]. It is worth noting that both enantiomers of the catalyst 9 can be obtained from commercial sources or easily synthesized from (salen)Co(II), which enhances the advantage of this approach.…”

Synthesis of Optically Active Monoesters via Kinetic Resolution by Chiral Co (Salen) Complex Immobilized on Mesoporous BEA

“…Various strategies have been explored to increase the catalytic efficiency of heterogenized salen catalysts. Some approaches were demonstrated successfully to date in the asymmetric catalysis by adopting the methodologies of adsorption, covalent bonding, as well as ship-in-bottle for immobilization of salen complexes [11][12][13][14][15][16][17][18][19].…”

Non-Covalent Immobilization of Chiral (Salen) Complexes on HF-treated Mesoporous MFI-type Zeolite for Asymmetric Catalysis

“…5,6 Various strategies have been explored and developed to enhance the catalytic efficiency of heterogenized salen complexes. Some approaches were demonstrated successfully to date in the asymmetric catalysis by using dimeric, 5 dendrimeric, 6 polymeric 7,8 and supported-type catalysts. 9,10 Over the last two decades, salen complexes have been successfully synthesized inside the supercages of X, Y, EMT zeolites.…”