Synthesis of 3,3-disubstituted oxindoles through Pd-catalyzed intramolecular cyanoamidation

Abstract

The cyanoamidation of olefins was achieved. When N-(2-vinylphenyl)cyanoformamides were treated with palladium catalyst, intramolecular cyanoamidation took place to give corresponding 3, 3-disubstituted oxindoles. P(t-Bu)3 showed a remarkable effect on this reaction. When it was used with Pd(dba)2, the reaction was completed in 15 min at 100 oC for many substrates. Furthermore, the enantioselective cyanoamidation was accomplished with Pd(dba)2 and an optically active phosphoramidite to provide optically active 3, 3-disubstituted oxindoles. Manipulation of the resulting oxindoles has been studied.