Synthesis of α-amino acids by reaction of aziridine-2-carboxylic acids with carbon nucleophiles
作者:Kenneth J. M. Beresford、Nicola J. Church、Douglas W. Young
DOI:10.1039/b605026n
日期:——
homochiral alpha-amino acids have been prepared in good yield via regioselective reaction of higher order cuprates with (2S)-N-para-toluenesulfonylaziridine-2-carboxylic acid 4. The reaction was much less regioselective and low yielding when higher order cuprates were reacted with the more hindered aziridine carboxylic acid 30, the principal products being protected beta-amino acids. Reaction of lithium tr
Synthesis of α-amino acids by ring opening of aziridine-2-carboxylates with carbon nucleophiles
作者:Nicola J Church、Douglas W Young
DOI:10.1016/0040-4039(94)02198-k
日期:1995.1
Excellent regiospecificity has been achieved in the reaction of carbon nucleophiles with N-para-toluenesulfonylaziridine-2-carboxylic acid (6, R = H protected as the anion. This has been developed into a general and high yielding synthesis of optically pure α-amino acids containing one chiral centre. When the aziridine (20) containing a second chiral centre was used, only lithium trimethylsilylacetylide
Synthesis of stereospecifically labelled D-prop-2-ynylglycine and investigation of the action of D-amino acid oxidase
作者:Nicola J. Church、Douglas W. Young
DOI:10.1039/c39940000943
日期:——
Stereospecifically deuteriated samples of D-prop-2-ynylglycine 1 are synthesised by reaction of the labelled aziridines 13 with a carbon nucleophile followed by deprotection; incubation of these samples with D-amino acid oxidase indicates that, in formation of the lactone 5, deprotonation at C-3 is non-stereospecific, strongly supporting non-enzymatic deprotonation as a key step in the formation of this compound.
Cu(I)-Catalyzed Intramolecular Cyclization of Alkynoic Acids in Aqueous Media: A “Click Side Reaction”
作者:Thomas L. Mindt、Roger Schibli
DOI:10.1021/jo702030e
日期:2007.12.1
Alkynoicacids, in particular, 4-pentynoic acid derivatives, undergo intramolecular cyclizations to enol lactones under reaction conditions typically applied for the Cu(I)-catalyzed cycloaddition of terminal alkynes and azides (click chemistry). Starting from appropriate alkynoicacid derivatives, either enol lactones or 1,2,3-triazole click products can be obtained selectively by Cu(I) catalysis in
Synthesis of the suicide substrate D-propargylglycine stereospecifically labelled with deuterium and investigation of its oxidation by D-amino acid oxidase 1
作者:Nicola J. Church、Douglas W. Young
DOI:10.1039/a800579f
日期:——
Stereospecifically deuteriated samples of D-propargylglycine 1 have been prepared by reaction of the labelled Pmc-protected aziridine free acids 22 with a lithium acetylide followed by deprotection. These samples have been used to show that D-amino acid oxidase, in converting D-propargylglycine to the lactone 5, deprotonates C-3 in a non-stereospecific manner. This strongly supports the idea that non-enzymic deprotonation is a key step in the formation of this compound.