Mechanism and Stereocontrol: Enantioselective Addition of Pyrrole to Ketenes Using Planar-Chiral Organocatalysts


  • We acknowledge Prof. K. N. Houk, Prof. Gregory C. Fu, and Prof. Rich G. Carter for helpful discussions. Financial support was provided by Oregon State University.


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In control: The computational study of the title reaction catalyzed by the planar-chiral 4-(pyrrolidino)pyridine is reported (see scheme). The resting state is a chiral Brønsted acid complex and the rate-determining step involves a chiral base. The catalyst controls the enantioselectivity through a combination of stereoelectronic effects and CH⋅⋅⋅O interactions.