Enantioselective synthesis of dihydro-1H-benzindoles.

Gustavo P Silveira, Joseph P Marino

Index: J. Org. Chem. 78(7) , 3379-83, (2013)

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Abstract

The first examples of dihydro-1H-benzindoles by enantioselective γ-lactamization reaction of naphthyl sulfilimines with trichloroacetyl chloride in the presence of ZnCu as catalyst (≥98:2 er and 65-80% yields) are described. Products are obtained by [3,3]-sigmatropic rearrangement of the azasulfonium enolate or followed by a second allylic rearrangement that transfers chirality. The absolute stereochemistry was confirmed by X-ray crystallography, which provides support for the mechanisms proposed.