Host: Division of Organic Chemistry, The Pharmaceutical Society of Japan
Pages 90-91
Asymmetric functionalization of allenes via carbopalladation with chiral phosphine ligands was demonstrated and the stereochemical reaction path is discussed. Upon treatment with a palladium catalyst, allenes bearing o-iodoaryl groups and nucleophilic sites undergo intramolecular carbopalladation at the allene function, followed by intramolecular nucleophilic substitution reactions, to provide a facile and direct entry to heterocycles or carbocycles in one-pot reactions. Use of chiral phosphine ligands in the above reactions provided optically active heterocycles such as tricyclic indoles with considerably high e.e.. The highest e.e. was obtained with (S)-Tol-BINAP as a ligand. The mechanism of the asymmetric induction is discussed.
