1. Desymmetrization of Geminal Difluoromethylenes using a Palladium/Copper/Lithium Ternary System for the Stereodivergent Synthesis of Fluorinated Amino Acids.
- Author
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Luo, Yicong, Ma, Yuqi, Li, Guanlin, Huo, Xiaohong, and Zhang, Wanbin
- Subjects
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AMINO acid synthesis , *TERNARY system , *PALLADIUM , *AMINO acids , *DENSITY functional theory , *SCHIFF bases , *ALLYLIC amination , *COPPER - Abstract
Fluorinated amino acids and related peptides/proteins have been found widespread applications in pharmaceutical and agricultural compounds. However, strategies for introducing a C−F bond into amino acids in an enantioselective manner are still limited and no such asymmetric catalysis strategy has been reported. Herein, we have successfully developed a Pd/Cu/Li ternary system for stereodivergent synthesis of chiral fluorinated amino acids. This method involves a sequential desymmetrization of geminal difluoromethylenes and allylic substitution with amino acid Schiff bases via Pd/Li and Pd/Cu dual activation, respectively. A series of non‐natural amino acids bearing a chiral allylic/benzylic fluorine motif are easily synthesized in high yields with excellent regio‐, diastereo‐, and enantioselectivities (up to >20 : 1 dr and >99 % ee). A density functional theory (DFT) study revealed the F−Cu interaction of the allylic substrate and the Cu catalyst significantly influence the stereoselectivity. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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