Du, Chongyang et al. published their research in Chinese Journal of Chemistry in 2020 | CAS: 2387-23-7

1,3-Dicyclohexylurea (cas: 2387-23-7) belongs to amides. Because of the greater electronegativity of oxygen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors. Amides are not in general accessible by the direct condensation of amines with carboxylic acids for two reasons: first, both components are readily deactivated by a transfer of a proton from the acid to the amine and second, the hydroxy unit on the carbonyl of the acid is a relatively poor leaving group. Nevertheless, the formation of five- and six-membered rings is often surprisingly simple provided that other factors can be brought into play to assist in the condensation.Name: 1,3-Dicyclohexylurea

Zinc Powder Catalysed Formylation and Urealation of Amines Using CO2 as a C1 Building Block was written by Du, Chongyang;Chen, Yaofeng. And the article was included in Chinese Journal of Chemistry in 2020.Name: 1,3-Dicyclohexylurea This article mentions the following:

The zinc powder catalyzed formylation and urealation of secondary amines e.g., N-methylaniline and primary aromatic amines RNH2 (R = Ph, 2,4,6-trimethylphenyl, cyclohexyl, etc.) with CO2 and (EtO)3SiH under solvent-free condition were reported. Using 2 mol% zinc powder as the catalyst, a series of secondary amines, both the aromatic ones and the aliphatic ones can be formylated into formamides e.g., N-methyl-N-phenylformamide. When primary aromatic amines were used as the substrates, the reactions produce urea derivatives RNHC(O)NHR. The electronic and steric effects from the substrates on the formylation and urealation reactions were observed and discussed. The recovery and reusability of zinc powder were investigated, showing that zinc powder can be reused in the formylation reaction without loss of catalytic activity. The anal. on the reactants/products mixture after filtering out the zinc powder showed that zinc concentration in the mixture is low to 1 ppm. The pathways for the formylation and urealation of amines with this catalytic system were also investigated and related to the different substrates. In the experiment, the researchers used many compounds, for example, 1,3-Dicyclohexylurea (cas: 2387-23-7Name: 1,3-Dicyclohexylurea).

1,3-Dicyclohexylurea (cas: 2387-23-7) belongs to amides. Because of the greater electronegativity of oxygen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors. Amides are not in general accessible by the direct condensation of amines with carboxylic acids for two reasons: first, both components are readily deactivated by a transfer of a proton from the acid to the amine and second, the hydroxy unit on the carbonyl of the acid is a relatively poor leaving group. Nevertheless, the formation of five- and six-membered rings is often surprisingly simple provided that other factors can be brought into play to assist in the condensation.Name: 1,3-Dicyclohexylurea

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics