Synthesis 2025; 57(20): 2893-2908
DOI: 10.1055/a-2646-8383
Short Review

N-Alkylation by Hydrogen Borrowing: Pharmaceutical Applications and Comparison with Other Methods

Authors

  • Anju Nalikezhathu

    1   Medicinal Chemistry, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States (Ringgold ID: RIN4355)
  • Travis J. Williams

    2   Donald P. and Katherine B. Loker Hydrocarbon Institute, Wrigley Institute for Environment and Sustainability, and Department of Chemistry, University of Southern California, Los Angeles, CA, United States (Ringgold ID: RIN5116)

We thank the National Science Foundation (CHE-1856395) for sponsorship.


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Abstract

Formation of C–N bonds is a quintessential transformation in organic synthesis. Among the various methods to access them, hydrogen borrowing catalysis offers a green, atom-economical, and cost-effective approach, with water being the sole by-product. In this reaction, amines are alkylated using alcohol coupling partners in the presence of a transition metal catalyst. Several catalytic systems have been developed and utilized in the synthesis of pharmaceutical intermediates and complex natural products, thereby replacing conventional amination reactions with hydrogen borrowing reactions that deliver improved selectivity and yield. In this short review, we compare hydrogen borrowing N-alkylation with other classical and modern C–N bond forming reactions and discuss applications in pharmaceutical synthesis.



Publication History

Received: 10 April 2025

Accepted after revision: 01 July 2025

Accepted Manuscript online:
01 July 2025

Article published online:
07 August 2025

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