A catalytic asymmetric hetero-Diels–Alder reaction of olefinic azlactones and isatins: facile access to chiral spirooxindole dihydropyranones†
Abstract
A catalytic asymmetric hetero-Diels–Alder (HDA) reaction has been achieved through hydrogen-bond directed γ-addition of olefinic azlactones to isatins. This methodology provides an efficient access to spirooxindole dihydropyranones in moderate to good yields and with excellent enantioselectivities.