Copper phthalocyanine-conjugated pectin via the Ugi four-component reaction: An efficient catalyst for CO₂ fixation

Due to the cost-effectivity and biodegradability advantages of pectin, this type of polysaccharide attracted the attention of many researchers for catalyst construction. Accordingly, pectin was used as a green support in this study to construct an efficient heterogeneous catalytic system based on the conjugation of metal phthalocyanines. To end this, pectin was first oxidized with periodate oxidant agent to effectively immobilize a tetra-amino copper phthalocyanine (Cu-PcTA) through a green, simple, and an efficient one-pot Ugi four-component reaction (Ugi-4CR). Then, the catalytic activity of the copper phthalocyanine-conjugated pectin was investigated in the CO₂ fixation reaction to cyclic carbonates. Optimum catalytic conditions were as follows: 30 mg of prepared catalyst, 3 bar CO₂ pressure, 90 °C, 2 h, and TBAB as a co-catalyst. Pectin can successfully improve the catalytical properties of the Cu-PcTA over the CO₂ fixation reaction.