Studies On The Synthesis Of N-Sulfonylformamidines

The N-sulfonylamidine derivatives have an important position in the syntheticorganic chemistry,and they are often used as catalysts and metal ligands.Amidines are also important in medicinal chemistry because they are found in many bioactive natural products and have been identified as important pharmacophores.In recent years,there have some great progresses in the synthesis of amidines.However,the methods for synthesizing of N-sulfonyamidines have some shortcomings.For example,more reaction steps,special reagents are needed,and the raw materials are expensive and difficult to obtain,reaction conditions are not easy to control etc.On this basis,in this study we have developed a simple and green method for the synthesis of N-sulfonyl formamidines.Firstly,a direct and convenient metal-free method to prepare sulfonyl amidines in the presence of aqueous tert-butyl hydroperoxide(T-HYDRO)has been developed.Different tertiary and secondary amines were tested for compatibility with the oxidative conditions and could be coupled with sulfonyl azides to form the corresponding amidines in moderate to good yields.Secondly,the target product N-sulfonyl formamidines were synthesized by one pot three-component reaction by the using of sulfonyl azide,secondary amine and phenylacetaldehyde.The reaction condition of this method is mild and it does not require any special reagents,such as metal catalysts or oxidants.