Homogeneous Catalysis for the Conversion of CO₂, CO, CH₃OH, and CH₄ to C₂₊ Chemicals via C–C Bond Formation

In the past few decades, the advances of CO 2 reduction have been mostly focused on the synthesis of C 1 products, such as CO, formic acid, methanol, and methane. However, the syntheses of C 2+ products from generally abundant C 1 sources such as CO 2, CO, and CH 4 are traditionally more difficult because they involve two selective processes: activation of the C 1 source and simultaneous C–C bond formation. Recent advances in organometallic chemistry and catalysis provide effective means for the chemical transformation of C 1 sources to higher-energy C 2+ products under mild conditions. Moreover, the recent expansion of these mechanistically different methods has enabled the use of various C 1 sources to undergo either homocoupling or heterocoupling via C–C bond formation to generate various C 2+ products. In this review, we systematically present the various advances in C 1 to C 2+ conversions under homogeneous catalysis.