Enantioselective Organocatalytic Mannich Reaction and Fluorination Sequence of Pyrazolones to Isatin-derived Ketimines

摘要

An efficient asymmetric synthesis of oxindole-pyrazolone adducts via organocatalytic Mannich reaction of 1 -phenyl-1H-pyrazol-5(4H)-ones with ketimine derivatives derived from isatins, followed by sequential electrophilic fluorination, has been developed. This approach offers a facile way to prepare chiral 3-amino-3-(4-fluoropyrazol-4-yl)-substituted oxindole derivatives with a wide range of functional group tolerance.