Enantioselective Construction of Multi-Nitrogen-Containing Spirocycles: Asymmetric [3+2] Annulation of 4-Isothiocyanato­pyrazolones with Azodicarboxylates

Abstract

AbstractThe 4-isothiocyanatopyrazolones were exploited as a class of efficient synthons for the construction of triazoline derivatives via asymmetric [3+2] annulation with azodicarboxylates, providing a wide range of structurally diverse multi-nitrogen-containing spirocycles in excellent yields (up to 97%) with excellent enantioselectivities (up to 97% ee).