Mono- and Dinuclear Asymmetric Aluminum Guanidinates for the Catalytic CO<sub>2</sub> Fixation into Cyclic Carbonates

Rios Yepes, Yersica; Mesias-Salazar, Angela; BECERRA-AGUDELO, ALEXANDRA; Daniliuc, Constantin-Gabriel; Ramos, Alberto; Fernandez-Galan, Rafael; Rodriguez Dieguez, Antonio; Antinolo, Antonio; Carrillo-Hermosilla, Fernando; ROJAS-GUERRERO, RENE SEGUNDO


A set of trisubstituted guanidine ligands L1H2-L4H2 with general formula (PrHN)(2)CNR (R = Ph (L1H2), R = 2,4,6-Me3C6H2(L2H2), R = p-BrC6H4(L3H2), R = (C5H4)Fe(C5H5), Fc (L4H2)) was employed to synthesize a family of mono- and dinuclear asymmetric methyl aluminum guanidinato compounds ((L2H)AlMe2 (1), (L4H)AlMe2 (2), (L-1)Al2Me4 (3), (L-2)Al2Me4 (4), (L-3)Al2Me4 (5), (L-4)Al2Me4 (6), (L1H)(2)AlMe (7), (L2H)(2)AlMe (8), and (L4H)(2)AlMe (9)) that were characterized by NMR spectroscopy (1-9) and single-crystal X-ray diffraction (4 and 8). These compounds were tested as catalysts for the fixation of carbon dioxide with epoxides to give cyclic carbonates, using tetrabutylammonium iodide (TBAI) as cocatalyst. The reactions were performed under solvent-free conditions at 70 degrees C and 1 bar CO2 pressure. Complexes 1-9 were more active than their respective free guanidines under the same experimental conditions for the synthesis of styrene carbonate (11a). The dinuclear complex 6 was the most efficient and active catalyst for the synthesis of several monosubstituted carbonates (11a-1) with excellent conversions and selectivities. Furthermore, the formation of some disubstituted cyclic carbonates (13a-c) using this dinuclear aluminum catalyst was also studied.

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Título según WOS: Mono- And Dinuclear Asymmetric Aluminum Guanidinates for the Catalytic CO2Fixation into Cyclic Carbonates
Título según SCOPUS: ID SCOPUS_ID:85113612722 Not found in local SCOPUS DB
Título de la Revista: ORGANOMETALLICS
Volumen: 40
Fecha de publicación: 2021
Página de inicio: 2859
Página final: 2869