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 alpha,beta-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. (C) 2014 Elsevier Ltd. All rights reserved.