Cinchona Alkaloid Catalyzed Enantioselective Chlorination of 3-Aryloxindoles

O‐Benzoylquinidine is an effective organocatalyst for the asymmetric chlorination of 3‐aryloxindoles by using easily available N‐chlorosuccinimide (NCS) as chlorine source to give the corresponding 3‐aryl‐3‐chlorooxindoles in excellent yields and up to 93 % enantiomeric excess. We have developed a highly effective asymmetric α‐chlorination reaction of oxindoles by using an inexpensive cinchona alkaloid as the organocatalyst and N‐chlorosuccinimide (NCS) as the chlorination reagent under mild conditions, providing the corresponding 3‐aryl‐3‐chlorooxindoles in excellent yields and up to 93 % ee.