- Synthesis and reactions of α-fluoro-α-amino amides
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N-((S)-1-Phenylethyl)halofluoroethanamides have been investigated as precursors to N-protected α-fluoro-α-amino amides by nucleophilic displacement of halide with nitrogen nucleophiles such as potassium phthalimide, sodium succinimide, sodium glutarimide, trimethylamine and sodium azide. With single diastereoisomers of the iodofluoroethanamide, clean inversion of configuration occurs at room temperature, but subsequent epimerisation may occur as a result of the liberated iodide. The α-fluoro-α-amino amides made underwent a wide variety of reactions depending on conditions, but in many cases the carbon-fluorine bond was compromised. However, reacting trimethylamine and N-((S)-1-phenylethyl)iodofluoroethanamide gave the corresponding α-fluorobetaine amide, and subsequent acidic hydrolysis led to α-fluorobetaine as the first example of an 'unprotected' α-fluoroamino acid.
- Bailey, Patrick D.,Boa, Andrew N.,Clayson, Joanne
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experimental part
p. 1724 - 1736
(2009/05/09)
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- Synthesis and reactivity of 1-substituted 2-fluoro- and 2,2-difluoroaziridines
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(Chemical Equation Presented) A straightforward synthesis toward 2-fluorinated aziridines was developed via ring closure of β-fluorinated β-chloroamines, which were obtained via reduction of the corresponding α-fluorinated amides by borane. When 1-benzyl-2-fluoroaziridine was treated with methanol, reaction occurred at the 2-position, giving rise to N-benzyl-2,2-dimethoxyethylamine, while in the case of 1-benzyl-2,2- difluoroaziridine the 3-position was attacked, giving rise to N-benzyl-2-methoxyacetamide. These reactions point to the divergent reactive behavior of monofluoro- and difluoroaziridines.
- Verniest, Guido,Colpaert, Filip,Van Hende, Eva,De Kimpe, Norbert
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p. 8569 - 8572
(2008/02/13)
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- Synthesis of α-heterosubstituted glycine derivatives from dihaloethanamides
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A range of protected α-heterosubstituted analogues of glycine were synthesised from starting materials of the type CHFX-CONHR [X = Cl, Br, I; R = CH2Ph, (s)-CHMePh]; the final products included derivatives of glycine possessing N, O, F or S in the α-position, and the first example of a free α-fluoro-α-amino acid (α-fluorobetaine) whose structure was confirmed by X-ray crystal structure determination.
- Bailey, Patrick D.,Baker, S. Richard,Boa, Andrew N.,Clayson, Joanne,Rosair, Georgina M.
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p. 7755 - 7758
(2007/10/03)
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