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Atmospheric-Pressure Conversion of CO(2) to Cyclic Carbonates over Constrained Dinuclear Iron Catalysts

[Image: see text] The conversion of CO(2) and epoxides to cyclic carbonates over a silica-supported di-iron(III) complex having a reduced Robson macrocycle ligand system is shown to proceed at 1 atm and 80 °C, exclusively producing the cis-cyclohexene carbonate from cyclohexene oxide. We examine the...

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Detalles Bibliográficos
Autores principales: Pappuru, Sreenath, Shpasser, Dina, Carmieli, Raanan, Shekhter, Pini, Jentoft, Friederike C., Gazit, Oz M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2022
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9301958/
https://www.ncbi.nlm.nih.gov/pubmed/35874206
http://dx.doi.org/10.1021/acsomega.2c02488
Descripción
Sumario:[Image: see text] The conversion of CO(2) and epoxides to cyclic carbonates over a silica-supported di-iron(III) complex having a reduced Robson macrocycle ligand system is shown to proceed at 1 atm and 80 °C, exclusively producing the cis-cyclohexene carbonate from cyclohexene oxide. We examine the effect of immobilization configuration to show that the complex grafted in a semirigid configuration catalytically outperforms the rigid, flexible configurations and even the homogeneous counterparts. Using the semirigid catalyst, we are able to obtain a TON of up to 800 and a TOF of up to 37 h(–1) under 1 atm CO(2). The catalyst is shown to be recyclable with only minor leaching and no change to product selectivity. We further examine a range of epoxides with varying electron-withdrawing/donating properties. This work highlights the benefit arising from the constraining effect of a solid surface, akin to the role of hydrogen bonds in enzyme catalysts, and the importance of correctly balancing it.