An asymmetric conjugate addition of aldehydes with -azaxylylene intermediates (indol-2-ones) from 3-bromooxindoles has been developed. The use of a novel spiro-pyrrolidine (SPD)-derived bifunctional -sulfonylated amide catalyst is essential for a highly diastereo- and enantioselective transformation to provide a wide array of enantioenriched C3 quaternary oxindoles with structurally diverse β-aldehyde appendages. Further application of this synthetic methodology enables the construction of the tricyclic cores of akuammiline-type alkaloids.
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