Both carbon dioxide‐ (CO2) and biomass‐based molecules have recently been regarded as renewable, abundant, environmentally benign, and attractive carbon feedstocks for organic synthesis. Therefore, a mild and efficient method for the synthesis of 1,3‐oxazolidin‐2‐ones was developed through a “green” four‐component coupling reaction by using CO2, biomass‐based aldehydes such as furfural and 5‐hydroxymethylfurfural (HMF), terminal aromatic alkynes, and primary aliphatic amines with copper iodide as a catalyst. 24 Furyl‐substituted 1,3‐oxazolidin‐2‐ones were obtained in 29–84 % yield from the four‐component coupling reaction. Moreover, the coupling reaction was applicable to the syntheses of furyl‐containing bisoxazolidinone and polyoxazolidinone under mild conditions.

A transition-metal-free synthetic method of various ynones via decarboxylative alkynylation of α-keto acids is described. The reaction is carried out under mild conditions and exhibits remarkable tolerance of functional groups. The mechanism of a radical process is proposed in the reaction.

Chemical transformation of carbon dioxide (CO2) into fine chemicals such as oxazolidinones and carbamates is mainly reported using transition-metal complexes as homogeneous catalysts. Herein, we demonstrate that a heterogeneous catalyst of highly dispersed Cu (Cu/NHPC) supported on hierarchically porous N-doped carbon (NHPC) can efficiently promote CO2 fixations to oxazolidinones and β-oxopropylcarbamates. The obtained NHPC, assembled by ultrathin nitrogen-doped carbon nanosheets with a three-dimensional (3D) structure, is readily prepared by pyrolysis of a nitrogen-containing polymer gel (NPG) in the presence of an activator of potassium bicarbonate (KHCO3). The resulting NHPC shows specific Brunauer–Emmet–Teller (BET) surface areas up to 2054 m2 g–1 with a mean micro/mesopore size of 0.55/3.2 nm and a broad macropore size distribution from 50 to 230 nm. The Cu/NHPC can efficiently promote three-component coupling of CO2, amines, and propargyl alcohols for syntheses of various oxazolidinones and β-oxopropylcarbamates with yields up to 99% and a wide substrate scope. Moreover, the Cu/NHPC exhibits excellent recyclability in CO2-to-oxazolidinone transformation during nine-time recycling. The research thus develops an NHPC-based heterogeneous Cu catalyst for green transformation of CO2.