60006-25-9Relevant articles and documents
Enol-functionalized N-heterocyclic carbene lanthanide amide complexes: Synthesis, molecular structures and catalytic activity for addition of amines to carbodiimides
Li, Zhi,Xue, Mingqiang,Yao, Haisheng,Sun, Hongmei,Zhang, Yong,Shen, Qi
, p. 27 - 34 (2012)
Reaction of LnCl3 (Ln = Y, Nd, Sm and Yb) with enol-functionalized imidazolium salt H2LBr (L = 4-OMe-C 6H4COCH{C(NCHCHNiPr)}) and NaN(TMS)2 at a molar ratio of 1:4:1 in THF at room temperature afforded the corresponding novel enol-functionalized N-heterocyclic carbene (NHC) lanthanide amides L 2LnN(TMS)2 (Ln = Y (1), Nd (2), Sm (3), Yb (4)) in 37-40% yields. Molecular structures of 1-4 were determined by X-ray structure analyses. All complexes adopt monomeric structures where each 5-coordinated metal is coordinated by two NHC ligands and one amido group.in distorted trigonal bipyramid geometry. All complexes, especially Yb complex (4), were found to be highly active precatalysts for the catalytic addition of amines to carbodiimides giving guanidines. The system with 4 shows good functional group tolerance and a wide scope of amines including primary and secondary cyclic amines.
Catalytic C-N bond formation in guanylation reaction by N-heterocyclic carbene supported magnesium(II) and zinc(II) amide complexes
Baishya, Ashim,Barman, Milan Kr.,Peddarao, Thota,Nembenna, Sharanappa
, p. 112 - 118 (2014/09/17)
The catalytic activity of N-heterocyclic carbene (NHC) supported magnesium(II) and a zinc(II) amide complex towards the addition of N-H bond of amine to carbodiimide was studied. Treatment of a free carbene i.e., 1,3-di-tert-butylimidazol-2-ylidene (ItBu) with magnesium and zinc bis(amide) i.e., M[N(SiMe3)2]2, M = Mg or Zn in toluene led to the formation of ItBu:M[N(SiMe3) 2]2, M = Mg(1) and Zn(2) compounds, respectively. Both 1 and 2 were characterized by multinuclear (1H, 13C and 29Si) NMR spectroscopy and single X-ray crystal structure analysis. Solid state structures revealed that both complexes are monomeric in nature and their magnesium and zinc atoms are three coordinated and distorted trigonal planar in geometries. Furthermore, compounds 1 and 2 were tested as catalysts for the guanylation reaction of addition of amine to carbodiimide and turned to be excellent catalysts.
First iron-catalyzed guanylation of amines: A simple and highly efficient protocol to guanidines
Pottabathula, Srinivas,Royo, Beatriz
supporting information; experimental part, p. 5156 - 5158 (2012/09/22)
The first iron-catalyzed guanylation of amines is reported. Commercially available Fe(OAc)2 acts as an excellent catalyst for the addition of amines to carbodiimides. The reaction is broadly applicable to a variety of primary, secondary, and heterocyclic amines, and tolerates a wide range of functionalities allowing the easy preparation of a large family of guanidines. The low price and low toxicity of the commercially available iron catalyst make this methodology highly attractive.
