Ag(Ⅰ) Catalyzed Acetylene Amine Cyclization-Michael Addition Cascade Reaction

Azomethine ylides, as a very important intermediate in organic reaction, has received great attentions recent years. Especially the 1,3-dipolar cycloaddition with electron-deficient conjugated alkenes catalyzed by metal or organo-catalysts, is one of the most powerful methodologies for preparing the substituted pyrrolidines. With the development of new catalysts and new catalytic systems, the structural scope of the azomethine ylide precursor and the dipolarophile has been explored. Even so, the reactions for some less active azomethine ylides subject to further research.We found that under the catalyzed by Ag(Ⅰ), the acetylene amine derive from glycine esters, could react with nitro olefins. During the cascade reaction of cyclization and Michael addition, a wide range of substituted 3,4-dihydro-2H-pyrrole could synthetize in a very convenient way. In this reaction, the Ag(Ⅰ) do as the catalyst of the first cyclization, and the catalyst of the second Michael addition reaction as well. This transformation could get the cascade reaction product in medium yield from the one-pot reaction. And we could also get better result from the separated reaction. This is an effective and convenient way to synthesize a wide range of substituted 3,4-dihydro-2H-pyrrole。...