Stereoselective synthesis of trifluoroethyl 3,2'-spirooxindole γ-lactam through the organocatalytic cascade reaction of 3-((2,2,2-trifluoroethyl)amino)indolin-2-one.

Abstract

Newly designed 3-((2,2,2-trifluoroethyl)amino)indolin-2-ones were used for the facile synthesis of chiral fluoroalkyl-containing 3,2'-spirooxindole γ-lactam products. The secondary amine-catalysed Michael/hemiaminalization cascade reaction of 3-((2,2,2-trifluoroethyl)amino)indolin-2-one with α,β-unsaturated aldehydes followed by oxidation can easily produce the desired products in high yields (up to 86%) with excellent enantioselectivities (up to 99% ee) and diastereoselectivities (up to >95 : 5 dr).