Nickel‐Catalyzed Enantioconvergent Allenylic Amination of Allenols Activated by Hydrogen‐Bonding Interaction with Methanol

• Published in: Angewandte Chemie International Edition 2024-10, Vol.63 (40), p.e202410743-n/a
• Main Authors: Zhang, Wen‐Qian, Lin, Zihan, Wu, Danxing, Wang, Yuhao, Hirao, Hajime, Gong, Liu‐Zhu
• Format: Article
• Language: English
• Subjects: allenylic substitution; Amination; Amines; Biological activity; Catalysts; Chemical bonds; Chemical reactions; Chemical synthesis; enantioconvergent amination; Enantiomers; Hydrogen; hydrogen-bonding activation; Intermediates; Methanol; Natural products; Nickel; nickel catalysis; Nucleophiles; Racemization
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.202410743

The ubiquitous nature of amines in drug compounds, bioactive molecules and natural products has fueled intense interest in their synthesis. Herein, we introduce a nickel‐catalyzed enantioconvergent allenylic amination of methanol‐activated allenols. This protocol affords a diverse array of functionalized allenylic amines in high yields and with excellent enantioselectivities. The synthetic potential of this method is demonstrated by employing bioactive amines as nucleophiles and conducting gram‐scale reactions. Furthermore, mechanistic investigations and DFT calculations elucidate the role of methanol as an activator in the nickel‐catalyzed reaction, facilitating the oxidative addition of the C−O bond of allenols through hydrogen‐bonding interactions. The remarkable outcomes arise from a rapid racemization of allenols enabled by the nickel catalyst and from highly enantioselective dynamic kinetic asymmetric transformation of η3‐alkadienylnickel intermediates. The first nickel‐catalyzed enantioconvergent allenylic amination of methanol‐activated allenols enables a diverse array of functionalized allenylic amines to be accessed in high yields and with excellent enantioselectivities.