Access to 2′,3′-dihydro-1′H-spiro[indoline-3,4′-pyridin]-2-ones via amino acid derived phosphine-catalyzed asymmetric [4+2] annulation with easily available oxindole-derived α,β-unsaturated imines

The phosphine-catalyzed asymmetric [4+2] annulation of vinyl ketones with more easily available oxindole-derived α,β-unsaturated imines has been further developed in the presence of an easily available multifunctional thiourea-phosphine catalyst derived from natural amino acid, providing the enantioselective synthesis of 2′,3′-dihydro-1′H-spiro[indoline-3,4′-pyridin]-2-ones in good yields and moderate de values with higher enantioselectivities under mild conditions.

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