“…Activation of CO 2 can be accomplished through reduction routes ( Francke et al, 2018 ; Melchionna et al, 2021 ) in which desirable products are carbon monoxide, formic acid, methanol, methane, or > C2 species ( Albero et al, 2020 ). Alternatively, carbon dioxide can be exploited in cyclic carbonates or heterocycle formation ( North et al, 2010 ; Fiorani et al, 2015 ; Yu and He, 2015 ; Guo et al, 2021 ; Vieira et al, 2018 , 2019 ; Faria et al, 2021 ) or as a single-carbon-atom building block for its fixation into organic compounds ( Liu et al, 2015 ; Cao et al, 2018 ; Cherubini-Celli et al, 2018 ; Tlili and Lakhdar, 2020 ; Zhang et al, 2020 ; Sahoo et al, 2021 ; Yuan et al, 2021 ; He et al, 2020 ) upon creation of new C-C or C-heteroatom bonds. Mechanistically, these processes can be accomplished through 1) the reduction of carbon dioxide to its radical anion, followed by its reaction with the organic scaffold (in dimethylformamide, E 0 (CO 2 /CO 2 •– ) = −2.21 V vs. saturated calomel electrode, SCE, corresponding to −1.97 V vs. standard hydrogen electrode) ( Lamy et al, 1977 ; Otero et al, 2006 ; Berto et al, 2015 ) or 2) upon the formation of reduced intermediates of the organic substrate accomplished through chemical, electrochemical, or photochemical routes and their subsequent reactivity with CO 2 ( Yuan et al, 2021 ).…”