Synthesis of α,ω-polyfluorinated α-amino acid derivatives and δ,δ-difluoronorvaline?

Organic & Biomolecular Chemistry Pub Date: 2016-01-29 DOI: 10.1039/C6OB00131A

Abstract

Intending to synthesize ω,ω-difluoroalkyl amino acid derivatives by oxidative desulfurization–fluorination reactions of suitable arylthio-2-phthalimido butanoates and pentanoates, in addition to small amounts of the target products, mainly α,ω-polyfluorinated amino acid derivatives were formed by additional sulfur-assisted α-fluorination. This novel structural motif was verified spectroscopically as well as by X-ray analysis. A plausible mechanism of formation is suggested. Using a different approach, δ,δ-difluoronorvaline hydrochloride was synthesized with at least 36% enantiomeric excess via deoxofluorination of the corresponding aldehyde.

Graphical abstract: Synthesis of α,ω-polyfluorinated α-amino acid derivatives and δ,δ-difluoronorvaline
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