Mitsunobu Approach to the Synthesis of Optically Active α,α-Disubstituted Amino Acids
Jonathan E. Green, David M. Bender, Stona Jackson, Martin J. O'Donnell and James R. McCarthy*
*Eli Lilly & Co., Lilly Corporate Center, Indianapolis, Indiana 46285, Email: jmccarthylilly.com
J. E. Green, D. M. Bender, S. Jackson, M. J. O'Donnell, J. R. McCarthy, Org. Lett., 2009, 11, 807-810.
DOI: 10.1021/ol802325h (free Supporting Information)
Chiral tertiary α-hydroxy esters were transformed to α-azido esters by Mitsunobu reaction with HN3. Reactions proceed at room temperature with high chemical yield using 1,1-(azodicarbonyl)dipiperidine (ADDP) and trimethylphosphine (PMe3) with complete inversion of configuration at the α-carbon. Several α,α-disubstituted amino acids were synthesized in high overall chemical yield and optical purity.
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