An asymmetric approach toward chiral multicyclic spirooxindoles from isothiocyanato oxindoles and unsaturated pyrazolones by a chiral tertiary amine thiourea catalyst
The first organocatalytic Michael-cyclization cascade reaction between isothiocyanato oxindoles and unsaturated pyrazolones has been developed. The multicyclic spiro[oxindole/thiobutyrolactam/pyrazolone] core structures containing three contiguous stereog