Reported herein is a bifunctional-organocatalyst-mediated enantioselective inverse-electron-demand 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines with azlactones. The strategy provides concise access to enantioenriched C1-substituted tetrahydroisoquinolines featuring a pyrazolidinone scaffold. Moreover, the scalability and practical utility of this protocol was well demonstrated by employing a gram-scale reaction and some representative transformations.
Keywords: cycloaddition; hydrogen bonds; lactones; organocatalysis; synthetic methods.
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