Details

Autor(en) / Beteiligte

• Sinha, Indranil
• Lee, Yuseop
• Bae, Choongman
• Tussupbayev, Samat
• Lee, Yujin
• Seo, Min-Seob
• Kim, Jin
• Baik, Mu-Hyun
• Lee, Yunho
• Kim, Hyunwoo

Titel

Computer-aided rational design of Fe(iii)-catalysts for the selective formation of cyclic carbonates from CO2 and internal epoxidesElectronic supplementary information (ESI) available: Experimental procedure and characterization of compounds (1H and 13C-NMR spectra), Cartesian coordinates of DFT-optimized structures and computed energy component. CCDC 1518349-1518352. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7cy01435j

Erscheinungsjahr

2017-10

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The catalytic mechanism of the cyclic carbonate formation reaction between CO 2 and internal epoxides promoted by Fe-salen and the Kleij catalyst was examined in detail to better understand how the catalytic efficiency can be increased. Specifically, we aimed to make the catalyst more chemoselective towards forming cyclic carbonates and preventing the competing side reaction leading to polycarbonates via ring-opening polymerization. A few rational design principles were derived and first tested using computer models based on density functional theory. The most promising candidate that was identified in the computer model was then prepared and found to display significantly enhanced reactivity towards forming the cyclic carbonates, supporting the validity of the mechanistic insights deduced from the computer simulations. We propose that a cyclic carbonate is formed most efficiently via an inner-sphere mechanism where both the CO 2 and epoxide substrates utilize the metal center for the key bond forming events. In contrast, the ring-opening polymerization uses an outer-sphere mechanism, where a carbonate attacks and ring-opens the epoxide bound to the metal without engaging the metal directly. These mechanistic differences are exploited to implement a chemoselective catalyst by enhancing the rate of the cyclic carbonate formation reaction while leaving the polymerization pathway largely unaffected. The mechanism of Fe-catalyzed cyclic carbonate formation of CO 2 and internal epoxides was studied to identify design strategies for more efficient catalysts.