Chemical CO2 fixation using a green biocatalytic system based on Ugi conjugated cobalt phthalocyanine on cellulose

Abstract

Polysaccharides, especially cellulose, have received great interest from chemists for catalyst construction due to their economic and biodegradability advantages. In this work, cellulose was employed as a green support for the preparation of a heterogeneous biocatalytic system through a sustainable metallophthalocyanine conjugation. To end this, cellulose was first oxidized using periodate and then the resulting aldehyde functionalized cellulose (OCell) took part in the Ugi four-component reaction (Ugi-4CR) of tetra-amino cobalt phthalocyanine (Co-PcTA), cyclohexyl isocyanide and p-toluic acid. The ability of the prepared material as a heterogeneous biocatalyst was studied in the synthesis of cyclic carbonates through CO₂ fixation in water as a green solvent. The results showed that cyclic carbonates were obtained with high efficiency in the shortest time. Other important advantages of the present biocatalyst include its non-hazardous nature, ease of operation, high CO₂ absorption capacity, good reusability, renewable and sustainable catalytic conversions, and no cobalt leaching in the reaction medium.