Efficient guanylation of aromatic and heterocyclic amines catalyzed by cyclopentadienyl-free rare earth metal amides

Diamido-supported rare earth metal amides with the general formula {(CH2SiMe2)[(2,6-iPr2C6H3)N]2}LnN(SiMe3)2(THF) [(Ln = Yb(1), Y(2), Dy(3), Sm (4), Nd (5)] were found to be highly efficient catalysts for the guanylation of both aromatic and heterocyclic amines under mild conditions. It is found that these catalysts are compatible with a wide range of substituents such as iPr, Me, and MeO having electron-donating property and substituents such as Cl, Br, and O2N having electron-withdrawing property on the aromatic rings of the aromatic or the heterocyclic amines. The methodology has also the advantages of easy preparation of the catalysts, quick conversion of the substrates to products, mild reaction conditions, and low catalyst loading.

Graphical abstractA new highly efficient method for the synthesis of guanidines having different substituents using the cyclopentadienyl-free diamido-supported rare earth metal amides {(CH2SiMe2)[(2,6-iPr2C6H3)N]2}LnN(SiMe3)2(THF) [(Ln = Yb(1), Y(2), Dy(3), Sm(4), Nd(5)] as catalysts was developed. This methodology has the advantages of easy preparation of the catalysts, low catalyst loading, quick conversion of substrates to products, mild reaction conditions, and compatibility with a wide range of substrates.Figure optionsDownload full-size imageDownload as PowerPoint slide