Synthesis of Lactones and Other Heterocycles.

Chemical fixation of CO2 into value-added chemicals represents a promising field in view of sustainable development and green synthesis. In this aspect, the construction of heterocyclic compounds from CO2 and readily available starting materials is particularly appealing in both organic and pharmaceutical fields since CO2 can be regarded as carbon and oxygen resource with advantages of abundance, renewability, non-toxicity, and non-flammability. In this chapter, we have summarized elegant protocols with elaborately designed substrates for the direct incorporation of entire CO2 molecule or "CO" or "C" fragments into lactones and other heterocycles such as oxazolidinones, cyclic carbonates, quinazoline-2,4(1H,3H)-diones, etc., through the formation of carbon-carbon, carbon-nitrogen and/or carbon-oxygen bonds promoted by homogeneous catalysts.