Abstract
The highly enantioselective preparation of spirooxindoles bearing α,α-disubstituted α-amino-β-keto esters was achieved through [4 + 1] annulation of oxindoles and α-imine-β-oxo-γ,δ-unsaturated esters under mild conditions in good yields (up to 82%) and stereoselectivities (up to >20:1 dr, 96% ee). The reaction is amenable to gram scale synthesis using catalyst loading as low as 1 mol %. The corresponding chiral α,α-disubstituted α-amino-β-keto esters could be easily transformed into cyclopenta[ b]indole derivatives without erosion of enantiopurity.
Original language | English |
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Journal | Organic Letters |
Volume | 20 |
Issue number | 10 |
Pages (from-to) | 2888-2891 |
ISSN | 1523-7060 |
DOIs | |
Publication status | Published - 2018 |