4894-12-6Relevant academic research and scientific papers
Synthesis, electrochemical, and spectroscopic studies of novel S-nitrosothiols
Soulère, Laurent,Sturm, Juan-Carlos,Nú?ez-Vergara, Luis J.,Hoffmann, Pascal,Périé, Jacques
, p. 7173 - 7180 (2007/10/03)
A series of S-nitrosothiol compounds, structurally related to the NO-donor S-nitroso-N-acetyl-D,L-penicillamine (SNAP) that contain amidin groups were synthesised by S-nitrosation of the corresponding thiols and characterised. The kinetics of decomposition were investigated and showed that the two adenine-based thionitrites exhibited an unusual stability in aqueous solution compared to SNAP, suggesting that these compounds may complex the traces of free copper ions present in solution, which is known to catalyze the decomposition of thionitrites. The electrochemical behaviour of these compounds and their nitric oxide-releasing potential were studied by means of cyclic voltammetry techniques on mercury and glassy carbon electrodes.
ASYMMETRIC HOMOGENOUS REDUCTION OF DEHYDROPEPTIDES
El-Baba, S.,Nuzillard, J. M.,Poulin, J. C.,Kagan, H. B.
, p. 3851 - 3862 (2007/10/02)
Monodehydropeptides with the dehydroaminoacid fragment in C-terminal or N-terminal position were synthetized as well as a family with the general formula Ac-ΔPhe-(Gly)n-Leu-OR (n = 0-2, R = H or Me).Asymmetric reduction of these compounds catalyzed by chiral rhodium complexes was investigated.The results were discussed in terms of double asymmetric induction.A method was developped to avoid the use of both enantiomers of the substrate or of the catalyst, it consists in the total reduction of a racemic dehydropeptide.The products distribution gives access to the two desired facial selectivities.
Amino Acids, 3. N-Acetylated α,β-Didehydro α-Amino Acid Derivatives by Nitrogen Elimination from α-Azidocarboxylic Acid Amides and α-Azido-ω-aminocarboxylic Acid Lactams with Rhenium Catalysts
Beisswenger, Thomas,Effenberger, Franz
, p. 1513 - 1522 (2007/10/02)
α-Azidocarboxylic acid amides 2 and α-azido-ω-aminocarboxylic acid lactams 6, respectively, react with acetic anhydride in the presence of rhenium catalysts by nitrogen elimination to give N-acetyl- 7 and N,N-diacetyl-α,β-didehydro-α-amino acid amides 8, α-acetylamino- 11 and α-diacetylamino-α,β-didehydro-ω-aminocarboxylic acid lactams 12, respectively.Reactions of the educts 6c,d - with a ring size 7 or 8 - additionally lead to the oxazoloazepine 14c and the oxazoloazocine 14d, respectively.
Studies Related to Thietan-2-ones. Part 1. Conversion of D-Penicillamine into DL-2-Methylpenicillamine using Thietan-2-one-based Chemistry
Al-Zaidi, Shakir M.R.,Crilley, Martine M. L.,Stoodley, Richard J.
, p. 2259 - 2266 (2007/10/02)
A series of N-substituted derivatives of (3R)-3-amino-4,4-dimethylthietan-2-one has been prepared from D-penicillamine (3).Attempts to effect the methylathion at position 3 of the N-acetyl (7a), N,N-diacetyl (12), N-benzyloxycarbonyl (7b), or N-(p-nitrobenzylidene) derivative (15a) were unrewarding.Although the N-benzylidene and N-furfurylidene derivatives (15b) and (15c) were successfully methylated at position 3 by using iodomethane and potassium t-butoxide in tetrahydrofuran (THF), best results were achieved by treating the N-(2-hydroxy-1-naphthylmethylene) derivative (15d) with iodomethane and sodium hydride in N,N-dimethylformamide.Cleavage of the imine linkage of the methylated derivatives of the thietanones (15c) and (15d), i.e. compounds (19b) and (19c), was effected by using, respectively, toluene-p-sulphonic acid in THF and dilute hydrochloric acid in acetone.The derived salts of (3RS)-3-amino-3,4,4-trimethylthietan-2-one, i.e. (21a) and (21b), underwent hydrolysis in boiling water to give the corresponding salts of DL-2-methylpenicillamine, i.e. (22a) and (22b).
