The Phenylsulfonyl Group as a Temporal Regiochemical Controller in the Catalytic Asymmetric 1,3-Dipolar Cycloaddition of Azomethine Ylides


  • This work was supported by the Ministerio de Ciencia e Innovación (MICINN, project CTQ2006-01121) and Consejería de Educación de la Comunidad de Madrid, Universidad Autónoma de Madrid (UAM/CAM project CCG07-UAM/PPQ-1670). A.L.P. thanks the CAM for a predoctoral fellowship. J.A. thanks the MICINN for a Ramón y Cajal contract. We thank Solvias AG (Dr. H.-U. Blaser, Solvias ligand kit) and Takasago (Dr. H. Shimizu and Dr. Wataru Kuriyama, segphos and DTBM-segphos) for generous loans of chiral ligands.


original image

Controlling the regioselectivity: The phenylsulfonyl group controlled the regioselectivity in the title reaction to afford pyrrolidine-2,3-dicarboxylates with good regioselectivity and high exo selectivity and enantioselectivity (see scheme). The products are precursors to substituted pyrrolidines and pyrrolines that are not attainable by direct 1,3-dipolar cycloadditions with typical acrylates.