80612-97-1Relevant academic research and scientific papers
Synthesis and preliminary biological evaluation of new phenolic and catecholic dehydroamino acid derivatives
Monteiro, Luís S.,Oliveira, Sandra,Paiva-Martins, Fátima,Ferreira, Paula M.T.,Pereira, David M.,Andrade, Paula B.,Valent?o, Patrícia
, p. 6199 - 6209 (2017)
A library of N-phenolic and N-catecholic dehydroamino acid derivatives was prepared using an innovative synthetic strategy that involves mild reaction conditions and simple work-up procedures. The method comprises coupling of phenolic or catecholic acids with β-hydroxyamino acids followed by tert-butyloxycarbonylation of all hydroxyl groups using tert-butyldicarbonate and 4-dimethylaminopyridine as catalyst. Treatment of these amino acids with N,N,N′,N′-tetramethylguanidine affords the corresponding O-tert-butyloxycarbonyldehydroamino acid derivative. Deprotection of the aromatic hydroxyl groups is carried out with trifluoroacetic acid. This synthetic strategy can be applied in a one-pot procedure and yields compounds that can be easily inserted into peptides or other biomolecules after cleavage of the C-protecting group. Preliminary studies of cell viability show that these new compounds display very low or no toxicity. These dehydroamino acids with a phenolic or catecholic moiety can have intrinsic biological activity or used to prepare new hydrogels that mimic mussel adhesive proteins.
A Bu4N[Fe(CO)3(NO)]-Catalyzed Hemetsberger–Knittel Indole Synthesis
Baykal, Aslihan,Plietker, Bernd
supporting information, (2020/02/20)
The nucleophilic Fe complex Bu4N[Fe(CO)3(NO)] (TBA[Fe]) catalyzes the direct intramolecular amination of aryl vinyl azides to give the corresponding indole derivatives in good to excellent yields.
Cu/Mn Co-oxidized cyclization for the synthesis of highly substituted pyrrole derivatives from amino acid esters: A strategy for the biomimetic syntheses of lycogarubin c and chromopyrrolic acid
Zhou, Nini,Xie, Tao,Liu, Lin,Xie, Zhixiang
, p. 6061 - 6068 (2014/07/21)
An effective and concise approach to synthesis of tetrasubstituted pyrroles from readily available amino acid esters by the promotion of Cu(OAc) 2 in conjunction with Mn(OAc)3 has been developed. This reaction proceeds through multiple dehydrogenations, deamination, and oxidative cyclization. This oxidized system tolerates substrates bearing various electron-donating or electron-withdrawing groups. With this methodology, several key intermediates of natural products have been effectively prepared, and the total syntheses of lycogarubin C and chromopyrrolic acid have been completed in high efficiency.
Synthesis of functionalized phenylalanine derivatives by ring opening reactions of 3-arylaziridine-2-carboxylic esters
Legters, Johan,Thijs, Lambertus,Zwanenburg, Binne
, p. 16 - 21 (2007/10/02)
Ring-opening reactions of 3-arylaziridine-2-carboxylic esters with various nucleophiles are described.Racemic methyl 3-(4-methoxyphenyl)-, 3-phenyl- and 3-(4-nitrophenyl)aziridine-2-carboxylate (1a, 1b and 1c, respectively) were selected as substrates.In the absence of acid, no ring opening occurred.On treatment with ethereal hydrogen chloride, 1a gave a mixture of diastereomers 2a, whereas 1b and 1c gave mixtures of regioisomers 2b/3b and 2c/3c, respectively.Boron-trifluoride etherate catalyzed reaction of 1a with benzenethiol and indole also resulted in the formation of diastereomeric ring-opened products 4a and 6a, respectively, due to the electron-releasing properties of the p-methoxy group.Only C3 attack was observed.Under the same conditions, 1b and 1c gave a clean SN2-type ring opening, leading to diastereomerically pure products 4b, 4c, 6b and 6c.Reaction of 1b with acetic acid gave 7 in an SN2-type ring opening at C3, followed by an O->N acyl shift.Treatment of enantiopure (+)-(2S,3R)-1b with benzenethiol, indole and acetic acid gave the corresponding enantiomerically pure β-functionalized α-amino acid derivatives.Functionalization of 1b at nitrogen strongly increased the reactivity: N-acylaziridine 8 isomerized to trans-oxazoline 11 when treated with boron trifluoride etherate in acetonitrile.
