Organocatalytic Enantioselective Alkylation of Pyrazol-3-ones with Isatin-Derived Ketimines: Stereocontrolled Construction of Vicinal Tetrasubstituted Stereocenters

A quinine-derived thiourea catalysed the enantioselective addition of 4-substituted pyrazolones to isatin-derived ketimines, providing a variety of aminooxindole-pyrazolone adducts containing congested vicinal tetrasubstituted stereocentres with excellent outcomes (up to 98% yield, >20:1 dr and 98% ee).Financial support from the MINECO (Gobierno de Espana and FEDER (EU)) (CTQ2013-47949-P) and from Generalitat Valenciana (ISIC2012/001) is gratefully acknowledged. C. V. thanks MINECO for JdC contract. Access to NMR, MS and X-ray facilities from the Servei central de support a la investigacio experimental (SCSIE)-UV is also acknowledged.Amr, FI.; Vila, C.; Blay, G.; Muñoz Roca, MDC.; Pedro, JR. (2016). Organocatalytic Enantioselective Alkylation of Pyrazol-3-ones with Isatin-Derived Ketimines: Stereocontrolled Construction of Vicinal Tetrasubstituted Stereocenters. Advanced Synthesis and Catalysis. 358(10):1583-1588. https://doi.org/10.1002/adsc.201600036158315883581