American Chemical Society
ol7b02150_si_001.pdf (10 MB)

Quinine-Based Trifunctional Organocatalyst for Tandem Aza-Henry Reaction-Cyclization: Asymmetric Synthesis of Spiroxindole-Pyrrolidine/Piperidines

Download (10 MB)
journal contribution
posted on 2017-08-28, 21:48 authored by Saumen Hajra, Bibekananda Jana
A quinine-derived trifunctional sulphonamide catalyst has been developed for the effective asymmetric organocatalytic tandem aza-Henry reaction-cyclization of isatin-derived ketimines and nitroalkane-mesylates for the synthesis of spiro-pyrrolidine/piperidine-oxindoles. Demethylation of traditional bifunctional catalyst to incorporate an additional hydrogen bonding C6′–OH group plays the key role toward remarkable enantioselectivity.