Recent advances in the incorporation of CO for C-H and C-C bond functionalization

Carbon dioxide (CO 2 ) has emerged as an exciting, cost-effective, abundant, and ready-to-use C1 source in synthetic organic chemistry. However, the thermodynamic stability and kinetic inertness of CO 2 limit its direct fixation, which can only occur in the presence of air-sensitive organometallic reagents, creating a hurdle for its practical utilization in synthetic chemistry. In the past decade, numerous research groups have explored the successful possibility of incorporating CO 2 into organic motifs by directly targeting C(sp 2 )-H, C(sp 3 )-H, and unsaturated C-C bonds. Furthermore, diverse methods utilizing metal-based redox catalysis, organic and metal-photo-redox catalysis, and metal-free carboxylation methodologies have been developed to achieve CO 2 -fixation on a wide variety of unsaturated, saturated, and aromatic motifs. This tutorial review aims to aid readers navigate through the development of CO 2 functionalization in this particular research area. Additionally, this review also provides an outline for approaching the synthetic challenges, addressing the potential pitfalls, and recognizing the future directions for CO 2 utilization. This tutorial review depicts the important aspects of these developments to help readers navigate the vast pool of tactics involving CO 2 -fixation, leading to valuable moieties that are widely employed in synthetic, pharmaceutical, material, and bio industries. Functionalization with CO 2 : This tutorial review is focused on various approaches developed so far for functionalization of unsaturated C-C & C-H bonds using CO 2 to achieve carboxylation, lactonization & lactamization by metal and metal free methods.