Carbon dioxide (CO ₂), as a one-carbon synthon, has many advantages such as abundant, non-toxic, clean and so on. So the reactions using CO ₂ as a one-carbon synthon have been widely concerned in organic chemistry. Transition-metal- catalyzed reaction of unsaturated hydrocarbons with CO ₂ to produce carboxylic acid is one of the most commonly-used method to convert CO ₂, and organometallic reagents can be added to the reaction as reducing agent. This kind of reaction can be realized by the strategy of tandem reaction. In the reaction, the unsaturated hydrocarbons react with transition-metal catalysts and organometallic reagents to generate new organometallic reagents in situ first, and then complete carboxylation with CO ₂. Common organometallic reagents such as organozinc reagents, Grignard reagents, and organoaluminum reagents can all achieve this kind of carboxylation reaction. In this review, reactions are divided according to the type of unsaturated hydrocarbons, and each type can also be divided into hydrocarboxylation and carbocarboxylation. This review would introduce reaction according to this classification.

Hydrosilylation of carbon dioxide (CO₂) is one of the most significant sustainable approaches for utilizing CO₂ as a C1 feedstock. This approach enables the conversion of CO₂ to value-added chemicals at various oxidation levels, such as formate, formaldehyde, methanol, or methane. Additionally, the formylation and/or alkylation of the N—H bonds of amines can also be achieved in certain catalytic systems with CO₂ and hydrosilanes. Currently, remarkable progress has been made in the field of CO₂ hydrosilylation. This focused review mainly describes advances in the design and catalytic performance of leading catalytic systems reported in the past three years, including noble transition metal catalysis, nonprecious transition metal catalysis, rare-earth metal catalysis, main-group metal catalysis, and metal-free catalysis. Moreover, current bottlenecks and perspectives of this field are also discussed.

Porous organic polymers (POPs) are a new class of porous materials that connect organic structural units by covalent bonds, having the features of various synthetic methods, adjustable pore properties, stable pore structures, low relative density and large specific surface areas. POPs have been applied in fields of gas adsorptions, separations and storage, optoelectronic devices, sensing and heterogeneous catalysis, showing the important application value. Carbon capture, utilization and storage (CCUS) technology is the unique way to significantly reduce carbon dioxide (CO₂) emissions from fossil fuels, and catalytic conversion of CO₂ into valuable fuels or industrial value-added products is an effective and potential strategy to solve the utilization of renewable energy and realize the development of green chemistry. In this review, the synthesis and properties of covalent-organic frameworks (COFs), covalent triazine frameworks (CTFs), hypercrosslinked polymers (HCPs), conjugated microporous polymers (CMPs) and polymer of intrinsic microporosity (PIMs) and their progress of chemical fixation of CO₂ in recent years, is reviewed, and the application prospects of POPs in CO₂ catalysis are prospected.

Reducing carbon dioxide emission and converting carbon dioxide from the air have always been a hot topic for researchers. Carbon dioxide is an ideal raw material for synthesizing organic compounds because of its good physical properties such as non-toxicity, abundance and easy availability. In recent years, hydrosilylation reaction has become an effective method to convert carbon dioxide into formate, formaldehyde, methanol, methane and other valuable chemical products under moderate conditions, which greatly promotes the conversion and utilization of carbon dioxide. The research progress on the design, synthesis and catalytic performance of catalytic systems used to catalyze the hydrosilylation for reduction of carbon dioxide is summarized and discussed. The reaction mechanism of hydrosilylation reduction of carbon dioxide is discussed, and the advantages and disadvantages of various catalyst systems are also analyzed. At last, the future research directions in this field are prospected.

Carbamate compounds exhibit a broad applicable scope in medicine, pesticide, resin modification, fabric finishing and organic synthesis. A methodology using ZnO/ionic liquids as the catalyst for the three-component coupling reactions of carbon dioxide (CO₂), secondary amines and propargylic alcohols to produce various β-oxopropylcarbamates was developed. This catalytic system exhibited robust recyclability and broad substrate scope. Moreover, it showed considerable catalytic activity under atmospheric CO₂, indicating its potential in carbon capture and utilization processes.

Carbon dioxide is a readily available, low-cost, abundant, non-toxic C1 source, which can potentially serve as an ideal building block in synthetic chemistry. Recently, much progress, expecially multi-component reactions (MCRs) has been achieved in construction of carbonyl-containing heterocycles through annulation by using carbon dioxide as carbonyl/carboxyl source. Herein, the advances on the annulation reaction of atmospheric CO₂ with N-, and O-nucleophiles for the constructioin of various carbonyl-containing heterocycles, including benzoxazin, cyclic carbamates, lactams, oxazolidine-2,4-diones are reviewed. In addition, the carboxylation of C-nucleophiles with CO₂ toward carboxylic acids is also summarized.

Industrial processes of fixing carbon dioxide (CO₂) lag far behind the carbon emission generated by human activity. Since CO₂ is an abundant, non-toxic, and cost-effective one carbon source, it is highly desirable to develop methodologies on converting CO₂ into valuable products for sustainable purpose. Based on the mechanistic insight of CO₂ activation by transition-metal catalyst and organocatalyst, a variety of efficient asymmetric CO₂ chemical fixation processes have been developed in recent years. This review discusses the advances of enantioselective synthesis of small molecules by asymmetric catalytic reactions with CO₂. The interaction between catalyst, CO₂ and substrate has been elaborated aiming to inspire the design of new catalytic systems for asymmetric CO₂ transformation.

Climate change and depletion of fossil fuels have drawn considerable attention. Considering carbon dioxide is both the dominant greenhouse gas and renewable C₁ source, CO₂ valorization into valuable chemicals is considered to reconcile the environment benefit and sustainable chemistry development. Unfortunately, the thermodynamic stability and kinetic inertness of CO₂ make its chemical transformation challenging. As a consequence, developing highly efficient catalytic systems and synthetic protocols is crucial for CO₂ conversion. In recent years, He's group made great progress on strategy design and catalyst development for CO₂ conversion. A series novel CO₂ conversion strategies are proposed, including CO₂ capture and in-situ transformation, hierarchical reductive functionalization of CO₂, designing thermodynamically favorable reactions by multi-component cascade reaction and photo-promoted CO₂ transformation. Concurrently, the corresponding highly efficient catalytic systems were also developed based on the reaction mechanism and thus CO₂ transformation was successfully performed under mild conditions. It is hoped that this review can arouse broad concern on CO₂ transformation and spur its further development.