Bimetallic scorpionate-based helical organoaluminum complexes for efficient carbon dioxide fixation into a variety of cyclic carbonates. Issue 10 (29th April 2020)

• Record Type: Journal Article
• Authors: Navarro, Marta; Sánchez-Barba, Luis F.; Garcés, Andrés; Fernández-Baeza, Juan; Fernández, Israel; Lara-Sánchez, Agustín; Rodríguez, Ana M.
• Is Part Of: Catalysis science & technology. Volume 10:Issue 10(2020)
• Page Start: 3265
• Page End: 3278
• Publication Date: 2020-04-29
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/d0cy00593b
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : The binuclear aluminum complexes [AlR2 (κ 2 - NN ′;κ 2 - NN ′)AlR2 ] with TBAB/PPNCl behave as excellent systems for cyclic carbonate formation from CO2 with challenging epoxides. Abstract : A new family of bimetallic helical aluminum complexes can be obtained via warming up the preliminary dinuclear adduct complexes, or alternatively, by direct heating of the protioligands with 2 equiv. of AlR3 . X-ray diffraction analysis corroborated both the high coordination versatility in the ligands and the existence of helical chirality in the complexes. DFT calculations confirmed the preferential arrangement of the ancillary scorpionates in the bimetallic complexes and rationalized the proposed reaction mechanism. Bimetallic complexes were investigated as catalysts in combination with halides for the cycloaddition reaction of CO2 with a wide range of epoxides for cyclic carbonate formation. These studies led to the development of a sustainable, inexpensive, efficient and selective bicomponent system with a very broad substrate scope, including internal and challenging bio-based trisubstituted terpene derived substrates, reaching high conversions for trans -limonene oxide under mild conditions (79% conv., 70 °C, 10 bar CO2, 1 mol%, 66 h).