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Updated: Dec 24, 2025
A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
Cationic Iridium/Chiral Bisphosphine-Catalyzed Enantioselective Hydroacylation of Ketones
Tomohiko Shirai1, Tomoya Iwasaki2, Kazuya Kanemoto3
1Department of Social Design Engineering, National Institute of Technology, Kochi College, 200-1 Monobe, Otsu, Nankoku, Kochi, 783-8508, Japan.
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.
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