258505-90-7Relevant articles and documents
Photochemical alkylation of glycine leading to phenylalanines
Knowles,Hunt,Parsons
, p. 7121 - 7124 (2000)
UV photolysis of protected glycines in the presence of di-tert-butyl peroxide, benzophenone and substituted toluenes is shown to lead to selective alkylation at the α-position. Phenylalanines are isolated in yields of generally > 50% (based on recovered s
Reactions of α-Substituted Glycine Derivatives with Stannanes in the Presence of Disulfides
Easton, Christopher J.,Peters, Steven C.
, p. 859 - 868 (2007/10/02)
Reactions of α-bromo-, α-benzoyloxy- and α-methoxy-substituted glycine derivatives with stannanes afforded the corresponding α-centred glycinyl radical, which reacted with di-t-butyl disulfide and diphenyl disulfide by homolytic substitution to give the corresponding α-t-butylthio- and α-phenylthio-substituted glycine derivatives, respectively.The glycinyl radical reacted with dibenzyl disulfide by displacement of benzyl radical to give a mixed disulfide, which was subsequently reduced to the corresponding α-benzylthio-substituted glycine derivative.In related reactions of a cystine derivative the corresponding S-glycinylcysteine derivative was produced, indicating that, while the chemical integrity of disulfide bonds in cystine derivatives is likely to be affected in radical reactions of peptides, the reactions are suitable for exploitation in the synthesis of cross-linked amino acid derivatives.
Selective Reaction of Glycine Residues in Hydrogen Atom Transfer from Amino Acid Derivatives
Burgess, Vicky A.,Easton, Christopher J.,Hay, Michael P.
, p. 1047 - 1052 (2007/10/02)
Relative rates of reaction of the N-benzoylamino acid methyl esters 1a-4a with N-bromosuccinimide and of 1a-4a with di-tert-butyl peroxide are reported.The selective reaction of glycine derivatives in these and other reactions of N-acylamino acid derivatives is attributed to the relative stability of intermediate radicals produced by hydrogen atom transfer.Radicals formed by hydrogen abstraction from N-acylglycine derivatives may adopt planar conformations which are relatively free of nonbonding interactions and in which there is maximum delocalization of the unpairedelectron, whereas radicals produced by similar reactions of derivatives of other amino acids are relatively unstable because of nonbonding interactions.In accord with this hypothesis, methyl pyroglutamate (5a) reacts at a faster rate than N-benzoylglycine methyl ester (1a) in reactions with either N-bromosuccinimide or di-tert-butyl peroxide.Anomalous rates of reaction of N-benzoylproline methyl ester (6a) are rationalized in terms of the regioselectivity of hydrogen atom transfer.Evidence for the mechanisms of reactions of 1a-6a is derived from product studies and by comparison of the relative rates of reactions of 1a-6a with those of the deuteriated amino acid derivatives 1b, 2b, 3b,c, 5b, and 6b,c.
