CO2 and Organic Carbonates for the Sustainable Valorization of Renewable Compounds

Abstract

The present chapter collects and describes representative examples from the current literature on the use of CO2 and Organic Carbonates for the Sustainable Valorization of Renewable Compounds. For the reader's convenience, after an introductory section aimed at highlighting both the potential and challenges associated with the chemical upgrading of renewable compounds, topics are organized in three parts surveying the following subjects: (i) catalytic and photocatalytic routes for both the reduction of CO2 and use of CO2 for the carboxylation of C(sp3)–H bonds and bio-based epoxides, and the methylation of amines; (ii) model strategies for carboxylation and alkylation reactions mediated by non-toxic dialkyl carbonates for the valorization of bio-based platform chemicals including glycerol, succinate, and dimethyl-2,5-furandicarboxylate, and renewable lactones, as well as natural polysaccharides (cellulose, starch, and chitin) and lignin; (iii) the sustainable synthesis of bio-polycarbonates and bio-polyurethanes via sequential transesterification/polycondensation reactions with dialkyl carbonates and cycloadditions of CO2 into renewable epoxides.

Sustainable valorisation of renewables through dialkyl carbonates and isopropenyl esters

“…Particularly, some of our contributions in 2018-2019 surveyed the role of carbon dioxide (CO 2 ) and one of its most interesting commercial derivatives, dimethyl carbonate (DMC), in the chemical upgrading of bio-based compounds and polymers through a variety of reactions including catalytic, photocatalytic and thermal transformations of insertion, CH-bond activation, methylation, methoxycarbonylation (transcarbonation and carbamation), and polymerization. [10][11][12] This lively sector is constantly fuelled by new findings describing benefits and innovations not only in terms of efficiency and safety, but more generally, of process intensification, low-to-zero waste/emissions and carbon footprint minimisation. The lack of toxicity and the versatile reactivity of DMC make it an ideal green reagent to convey both CO 2 and/or methyl function in chemical processes.…”

One-Pot Tandem Catalytic Epoxidation—CO2 Insertion of Monounsaturated Methyl Oleate to the Corresponding Cyclic Organic Carbonate

“…Ever-increasing attention has been focused in recent decades on the synthesis of cyclic organic carbonates (COCs) from carbon dioxide. Although recent studies suggest that only less than 1% of CO 2 generated from anthropogenic emissions can be effectively recycled into chemicals [1,2] and that other trapping strategies are needed to reduce excess CO 2 , nonetheless the preparation of COCs via the catalytic activation of CO 2 remains one of the most efficient strategies in green organic synthesis for its exploitation as a C1 building block and for its fixation into stable organic products and/or polymers [3]. This is even truer when renewable bio-based feedstocks such as glycerol, carbohydrates, terpenes and vegetable oils (VOs) are used [4].…”