Construction of spirocycles containing highly substituted pyrroli-dine and 1-indanone motifs with spiro quaternary stereogenic centers via 1,3-dipolar cycloaddition of 2-alkylidene-1-indanone and azomethine ylides promoted by simple imidazolium salts

摘要

The 1,3-dipolar cycloaddition of 2-alkylidene-1-indanone with azomethine ylides has been developed successfully promoted by simple imidazolium salts to construct a variety of spirocycles containing highly substituted pyrrolidines efficiently, affording the corresponding compounds in excellent yields (up to 99%). The highly efficient catalytic system exhibited broad substrate scopes under mild conditions.