Organocatalytic Enantioselective [3+2] Cycloaddition of Azomethine Ylides and α,β-Unsaturated Aldehydes


  • This research was supported by the University of the Basque Country (Subvención General a Grupos de Investigación and UNESCO06/06) and the Spanish Ministerio de Educación y Ciencia (CTQ2005-02131/BQU).


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One out of a possible 16: Commercially available α,α-diphenylprolinol catalyzes the [3+2] cycloaddition of α,β-unsaturated aldehydes with azomethine ylides derived from imines to produce pyrrolidines as single regioisomers with excellent diastereo- and enantioselectivities (see scheme; R1=aryl; R2=alkyl, aryl, 2-furyl). A fourth stereocenter can be introduced subsequently with complete stereoselectivity.