we developed a one-pot synthesis of guanidine directly from isothiocyanate using DIB (diacetoxyiodobenzene) as a desulfurizing agent under micellar conditions in water. Our optimization study revealed that the use of 1 % TPGS-750-M as a surfactant with NaOH as an additive base at room temperature can convert a variety of isothiocyanates and amines into corresponding guanidines in excellent yields (69-95 %)
A facile high yielding process of guanidines is reported by reaction of amine nucleophiles on the oxidised thioureas in an aqueous medium using the unexploited reagents sodium chlorite and sodium metaperiodate for the oxidation of 1,3-disubstituted thioureas.
Zn(OTf)2-catalyzed addition of amines to carbodiimides: efficient synthesis of guanidines and unpredicted formation of Zn–N amido species
作者:Dongzhen Li、Jie Guang、Wen-Xiong Zhang、Yang Wang、Zhenfeng Xi
DOI:10.1039/b923249b
日期:——
Zn(OTf)2 acts as an excellent catalyst precursor for addition of various amine NâH bonds to carbodiimides under an atmosphere of air, offering a convenient synthesis of substituted guanidines with high functional-group tolerance. A ZnâN amido species is shown to act as the active species.
In this work, we developed the catalytic guanylation of thiourea using Ru(bpy)3Cl2 as a photocatalyst under irradiation by visible light. The conversion of various thioureas to the corresponding guanidines was achieved using 1–5 mol % of photocatalyst in a mixture of water and ethanol at room temperature. Key benefits of this reaction include the use of photoredox catalyst, low-toxicity solvents/base
conditions, we successfully demonstrated the formation of 30 different guanidine compounds, achieving yields ranging from fair to excellent. Furthermore, the synthesis method could be carried out on a gram scale with a good yield. This protocol stands out for its cost-effectiveness, step-economical design, high tolerance towards various functional groups, and environmentally friendly reaction conditions