The review discusses the use of carbon dioxide (CO₂) as a renewable one-carbon (C1) building block in organic synthesis. CO₂ is a waste product from fossil fuel combustion, biological processes, and industrial activities. Recent advances in organometallic chemistry and catalysis have enabled the efficient transformation of CO₂ into useful chemicals under mild conditions. This approach could contribute to a more sustainable use of resources. CO₂ is the most stable form of oxidized carbon and is thermodynamically stable and kinetically inert, making it challenging to activate. However, its abundance, availability, nontoxicity, and recyclability make it a valuable C1 building block. The review highlights various catalytic strategies for CO₂ valorization, including the catalytic production of cyclic carbonates and polycarbonates from epoxides, the reductive formylation and methylation of amines, and the oxidative cyclometallation of CO₂ with unsaturated hydrocarbons. Key catalytic systems include metalloporphyrins, salen complexes, and metal-free catalysts. The review also discusses the use of CO₂ in the synthesis of polycarbonates, the reductive methylation of amines, and the carboxylation of organoboron reagents, terminal alkynes, and aromatic compounds. Additionally, the review covers the photocatalytic reduction of CO₂ to CO, which is a promising approach for generating CO from CO₂ under visible light. The review emphasizes the importance of developing efficient and sustainable methods for CO₂ valorization, including the use of less reactive substrates, milder reaction conditions, and improved selectivity. The development of new catalysts and reaction conditions is crucial for the industrial application of CO₂ in organic synthesis. Overall, the review highlights the potential of CO₂ as a sustainable and renewable resource in chemical synthesis.The review discusses the use of carbon dioxide (CO₂) as a renewable one-carbon (C1) building block in organic synthesis. CO₂ is a waste product from fossil fuel combustion, biological processes, and industrial activities. Recent advances in organometallic chemistry and catalysis have enabled the efficient transformation of CO₂ into useful chemicals under mild conditions. This approach could contribute to a more sustainable use of resources. CO₂ is the most stable form of oxidized carbon and is thermodynamically stable and kinetically inert, making it challenging to activate. However, its abundance, availability, nontoxicity, and recyclability make it a valuable C1 building block. The review highlights various catalytic strategies for CO₂ valorization, including the catalytic production of cyclic carbonates and polycarbonates from epoxides, the reductive formylation and methylation of amines, and the oxidative cyclometallation of CO₂ with unsaturated hydrocarbons. Key catalytic systems include metalloporphyrins, salen complexes, and metal-free catalysts. The review also discusses the use of CO₂ in the synthesis of polycarbonates, the reductive methylation of amines, and the carboxylation of organoboron reagents, terminal alkynes, and aromatic compounds. Additionally, the review covers the photocatalytic reduction of CO₂ to CO, which is a promising approach for generating CO from CO₂ under visible light. The review emphasizes the importance of developing efficient and sustainable methods for CO₂ valorization, including the use of less reactive substrates, milder reaction conditions, and improved selectivity. The development of new catalysts and reaction conditions is crucial for the industrial application of CO₂ in organic synthesis. Overall, the review highlights the potential of CO₂ as a sustainable and renewable resource in chemical synthesis.