Study On The Asymmetric Construction Of CF₃-containing Spiro-oxindole

Isatin is a very important building block in organic synthesis. Spiro-oxindole derived from isatin is the core of many natural products and drug molecules. Study shows that various unnatural spiro-oxindoles also have very important biological activities and the possibility of a potential medicine. The development of efficient and facile method to synthesis optically active spiro-oxindole is very important to research of drugs.We described a new 1,3-dipolar cycloaddition reaction for the construction of optically active 5’-CF3 spiro[pyrrolidin-3,2’-oxindole]. A series of unprecedented 1,3-dipoles were obtained by condensation of CF3CH2NH2 with isatins. The 1,3-dipolar cycloaddition reactions of these ketimines with enals using R-2-(diphenyl((trimethylsilyl)oxy)-methyl)- pyrrolidine as catalyst gave the products bearing four contiguous stereogenic centers in excellent yields, diastereoselectivities and enantioselectivities.This research would provide an alternative asymmetric access to optical active 3-amino-bis-substituted oxindoles with considerable pharmaceutical utility.