Efficient Catalytic Kinetic Resolution of Spiro‐epoxyoxindoles with Concomitant Asymmetric Friedel–Crafts Alkylation of Indoles

Abstract

AbstractAn efficient process involving the catalytic kinetic resolution of racemic spiro‐epoxyoxindoles with the simultaneous enantioselective Friedel–Crafts alkylation of indoles has been realized using a chiral phosphoric acid catalyst. The reaction provides two useful intermediates in high yields and excellent enantioselectivities. Performing the catalysis on a gram scale led to (R)‐3‐(3‐indolyl)‐oxindole‐3‐methanol, which was used in the asymmetric formal total synthesis of (+)‐gliocladin C. Notably, the enantiomers (S)‐3‐(3‐indolyl)‐oxindole‐3‐methanol can be obtained easily by the reaction of the resolved spiro‐epoxyoxindole with indole.