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Updated: May 23, 2025
Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
Ion-Pair Hydrogen Atom Transfer Catalysis Enables Cr-Catalyzed Allylation of Ketones Using Hydrocarbon Alkenes
Suguru Arii1, Zonghan Yu1, Hongyu Chen1
1Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Abstract:
We report a catalytic allylation of ketones using simple hydrocarbon alkenes, enabled by a synergistic system comprising chromocene and photo-activatable ion-pair hydrogen atom transfer (IP-HAT) catalysts derived from a thiophosphoryl imide and N-heteroaromatics. This catalyst system generates highly nucleophilic, electron-rich allylchromium(III) species directly from unactivated alkenes, demonstrating broad applicability to various ketones, including aromatic, aliphatic, and multifunctional ketones. The reaction proceeds under mild conditions with high functional group tolerance. The modular design of the IP-HAT catalysts allows precise tuning of redox potential and HAT activity, with the enhanced reduction potential of the reduced N-heteroaromatics catalyst playing a pivotal role in efficiently regenerating the electron-rich chromocene(II) catalyst.
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