Cationic Iridium/Chiral Bisphosphine‐Catalyzed Enantioselective Hydroacylation of Ketones. Issue 12 (27th May 2020)

• Record Type: Journal Article
• Authors: Shirai, Tomohiko; Iwasaki, Tomoya; Kanemoto, Kazuya; Yamamoto, Yasunori
• Is Part Of: Chemistry, an Asian journal. Volume 15:Issue 12(2020)
• Page Start: 1858
• Page End: 1862
• Publication Date: 2020-05-27
• Subjects: hydroacylation -- ketone -- C−H activation -- cationic iridium -- enantioselective; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.202000386
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: A facile and convenient synthesis of the chiral phthalide framework catalyzed by cationic iridium was developed. The method utilized cationic iridium/bisphosphine‐catalyzed asymmetric intramolecular carbonyl hydroacylation of 2‐keto benzaldehydes to furnish the corresponding optically active phthalide products in good to excellent enantioselectivities (up to 98% ee ). The mechanistic studies using a deuterium‐labelled substrate suggested that the reaction involved an intramolecular carbonyl insertion mechanism to iridium hydride intermediate. In addition, we investigated the kinetic isotope effect (KIE) of intramolecular hydroacylation with deuterated substrate and determined that the C−H activation step is not included in the turnover‐limiting step. Abstract : A facile and convenient synthesis of a chiral phthalide framework catalyzed by cationic iridium was developed. The method utilized cationic iridium/bisphosphine‐catalyzed asymmetric intramolecular carbonyl hydroacylation of 2‐keto benzaldehydes to furnish the corresponding optically active phthalide products in good to excellent enantioselectivities (up to 98% ee ).