Iridium‐Catalyzed Intermolecular Asymmetric Dearomatization of β‐Naphthols with Allyl Alcohols or Allyl Ethers

• Published in: Angewandte Chemie International Edition 2017-03, Vol.56 (12), p.3237-3241
• Main Authors: Tu, Hang‐Fei, Zheng, Chao, Xu, Ren‐Qi, Liu, Xi‐Jia, You, Shu‐Li
• Format: Article
• Language: English
• Subjects: allylic substitution; asymmetric catalysis; dearomatization; iridium; naphthol
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201609654

An Ir‐catalyzed intermolecular asymmetric dearomatization reaction of β‐naphthols with allyl alcohols or allyl ethers was developed. When an iridium catalyst generated from [Ir(COD)Cl]2 (COD=cyclooctadiene) and a chiral P/olefin ligand is employed, highly functionalized β‐naphthalenone compounds bearing an all‐carbon‐substituted quaternary chiral center were obtained in up to 92 % yield and 98 % ee. The direct utilization of allyl alcohols as electrophiles represents an improvement from the viewpoint of atom economy. Allyl ethers were found to undergo asymmetric allylic substitution reaction under Ir catalysis for the first time. The diverse transformations of the dearomatized product to various motifs render this method attractive. Introducing asymmetry: The iridium catalyst generated from [{Ir(cod)Cl}2] (cod=cyclooctadiene) and a chiral P/olefin ligand facilitates the intermolecular asymmetric dearomatization of β‐naphthols with allyl alcohols or allyl ethers. Highly functionalized β‐naphthalenone compounds bearing an all‐carbon‐substituted quaternary chiral center were obtained in up to 92 % yield and 98 % ee.