33662-25-8Relevant academic research and scientific papers
Catalytic amidation of unactivated ester derivatives mediated by trifluoroethanol
Caldwell, Nicola,Jamieson, Craig,Simpson, Iain,Watson, Allan J. B.
, p. 9495 - 9498 (2015)
A catalytic amidation method has been developed, employing 2,2,2-trifluoroethanol to facilitate condensation of unactivated esters and amines, enabling the synthesis of a range of amide products in good to excellent yields. Mechanistic studies indicate the reaction proceeds through a trifluoroethanol-derived active ester intermediate.
Synthesis of amides and esters containing furan rings under microwave-assisted conditions
Janczewski, ?ukasz,Zieliński, Dariusz,Kolesińska, Beata
, p. 265 - 280 (2021/03/17)
In this work, we present a novel method for the synthesis of ester and amide derivatives containing furan rings (furfural derivatives) under mild synthetic conditions supported by microwave radiation. N-(Furan-2-ylmethyl)furan-2-carboxamide and furan-2-ylmethyl furan-2-carboxylate were produced using 2-furoic acid, furfurylamine, and furfuryl alcohol. The reactions were carried out in a microwave reactor in the presence of effective coupling reagents: DMT/NMM/TsO? or EDC. The reaction time, the solvent, and the amounts of the substrates were optimized. After crystallization or flash chromatography, the final compounds were isolated with good or very good yields. Our method allows for the synthesis of N-blocked amides using N-blocked amino acids (Boc, Cbz, Fmoc) and amine. As well as compounds with a monoamide and ester moiety, products with diamides and diester bonds (N,N-bis(furan-2-ylmethyl) furan-2,5-dicarboxamide, bis(furan-2-ylmethyl) furan-2,5dicarboxylate, and furan-3,4-diylbis(methylene) bis(furan-2-carboxylate)) were synthesized with moderate yields in the presence of DMT/NMM/TsO– or EDC, using 2,5-furan-dicarboxylic acid and 3,4-bis(hydroxymethyl)furan as substrates.
Cytotoxic activity of synthetic chiral amino acid derivatives
de Castro, Pedro P.,Siqueira, Raoni P.,Conforte, Luiza,Franco, Chris H.J.,Bressan, Gustavo C.,Amarante, Giovanni W.
, p. 193 - 200 (2019/12/28)
Cancer is a chronic degenerative disease considered one of the most important causes of death worldwide. In this context, a series of dual-protected amino acid derivatives was synthesized and evaluated as potential novel anticancer agents. The 40 derivatives were prepared in up to three reaction steps. The cytotoxic activities were screened in vitro against a panel of tumor and non-tumor cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Among the synthesized derivatives, three of them showed promising activity against cancer cells with half-maximal inhibitory concentration (IC50) ranging between 1.7-6.1 μM. The most promising derivative, bearing both a lipophilic N-alkyl diamine moiety and a protected amino acid scaffold showed a selectivity index of 3.4 towards tumor cells. The N-alkyl diamine moiety seems to play a crucial role in the enhancement of the anticancer activity. On the other hand, the incorporation of an amino acid scaffold resulted in increase in the selectivity towards cancer cell lines.
Catalytic dehydrative peptide synthesis with gem-diboronic acids
Michigami, Kenichi,Sakaguchi, Tatsuhiko,Takemoto, Yoshiji
, p. 683 - 688 (2020/01/02)
Alkane-gem-diboronic acids have emerged as versatile organoboron catalysts for dehydrative amidation of α-Amino acids. A phenol-substituted multiboron catalyst with a B-C-B structure outperformed simple arylboronic acids in the condensation of α-Amino acids with suppressed epimerization of electrophiles. gem-diboronic acid catalysis were compatible with various O, N, and S-functionalized α-Amino acids bearing N-protecting groups including common carbamates used in peptide synthesis (Boc, Cbz, Fmoc). N-Trifluoroacetyl protection enabled an unprecedented catalytic dehydrative peptide synthesis at room temperature. Preliminary mechanistic studies revealed carboxylate-binding nature of gem-diboronic acids, orthogonal to the activation of carboxylic acids by arylboronic acids. The distinctive reactivity of the gem-diboronic acids would open prospects for mild catalytic peptide condensation.
Graphene oxide: A convenient metal-free carbocatalyst for facilitating amidation of esters with amines
Patel, Khushbu P.,Gayakwad, Eknath M.,Shankarling, Ganapati S.
, p. 2661 - 2668 (2020/02/20)
Herein, we report a graphene oxide (GO) catalyzed condensation of non-activated esters and amines, that can enable diverse amides to be synthesized from abundant ethyl esters forming only volatile alcohol as a by-product. GO accelerates ester to amide conversion in the absence of any additives, unlike other catalysts. A wide range of ester and amine substrates are screened to yield the respective amides in good to excellent yields. The improved catalytic activity can be ascribed to the oxygenated functionalities present on the graphene oxide surface which forms H-bonding with the reactants accelerating the reaction. Improved yields and a wide range of functional group tolerance are some of the important features of the developed protocol.
Water-Tolerant and Atom Economical Amide Bond Formation by Metal-Substituted Polyoxometalate Catalysts
De Azambuja, Francisco,Parac-Vogt, Tatjana N.
, p. 10245 - 10252 (2019/11/03)
A simple, safe, and inexpensive amide bond formation directly from nonactivated carboxylic acids and free amines is presented in this work. Readily available Zr(IV)- and Hf(IV)-substituted polyoxometalates (POM) are shown to be catalysts for the amide bond formation reaction under mild conditions, low catalyst loading, and without the use of water scavengers, dry solvents, additives for facilitating the amine attack, or specialized experimental setups commonly employed to remove water. Detailed mechanistic investigations revealed the key role of POM scaffolds which act as inorganic ligands to protect Zr(IV) and Hf(IV) Lewis acidic metals against hydrolysis and preserve their catalytic activity in amide bond formation reactions. The catalysts are compatible with a range of functional groups and heterocycles useful for medicinal, agrochemical, and material chemists. The robustness of the Lewis acid-POM complexes is further supported by the catalyst reuse without loss of activity. This prolific combination of Zr(IV)/Hf(IV) and POMs inaugurates a powerful class of catalysts for the amide bond formation, which overcomes key limitations of previously established Zr(IV)/Hf(IV) salts and boron-based catalysts.
Enantioseparation of Sulfoxides and Nitriles by Inclusion Crystallization with Chiral Organic Salts Based on l-Phenylalanine
Kodama, Koichi,Kanai, Hayato,Shimomura, Yuki,Hirose, Takuji
supporting information, p. 1726 - 1729 (2018/04/24)
Enantioselective inclusion of aromatic sulfoxides and nitriles was achieved in a host framework created by organic salts comprising achiral benzoic acids and a chiral primary amine (1a) derived from l-phenylalanine. Tuning of the combined achiral acid component successfully changed the chiral recognition ability of the organic salts. The guest molecules were hydrogen-bonded to form three-component inclusion crystals, and the enantiomers of nitriles and sulfoxides were separated with high selectivity up to 92 and 98 % ee. As far as we know, this is the first example of the enantioseparation of non-functionalized aromatic nitriles.
Dual-protected amino acid derivatives as new antitubercular agents
de Castro, Pedro P.,Campos, Débora L.,Pavan, Fernando R.,Amarante, Giovanni W.
, p. 1576 - 1580 (2018/06/06)
Tuberculosis is an infectious disease with high incidence and growing drug-resistant rates. In an attempt to develop new antitubercular agents, 35 compounds were synthesized, most of them bearing a carbamate and enantiopure amino acid moiety. These compounds had their activity evaluated toward a Mycobacterium tuberculosis strain (ATCC 27294) and cytotoxicity against fibroblast MRC-5 cells (ATCC CCL-171). Three of the prepared derivatives presented a good antimicrobial inhibition and two of them a moderate cytotoxicity. The lipophilicity seems to play a vital role in the cell growth activity, with best results for the derivatives with a higher logP.
Study on anti-proliferative activity in cancer cells and preliminary structure–activity relationship of pseudo-peptide chiral thioureas
Liao, Peng,Hu, Shi-Qin,Zhang, Hong,Xu, Liang-Bi,Liu, Jing-Zi,He, Bin,Liao, Shang-Gao,Li, Yong-Jun
, p. 300 - 304 (2018/02/15)
In our previous studies, we have shown that thiourea compounds containing phosphate esters have potent antitumor activity and can be used as a novel strategy for the development of antitumor agents. Herein, a series of novel phosphonate thioureas 5–38 have been synthesized, which were fully characterized by 1H NMR,13C NMR spectrum, elemental analysis. Three human cancer cell lines (Bcap-37, BGC-823, and PC-3) have been used to investigate these compounds’ antitumor activities. After the summarization of the structure–activity relationships, we found that the variation of R, R1, and R2 in these novel phosphonate thioureas contribute to the antitumor activities. All these SAR-guided efforts may lead to novel antitumor drugs in the market in the near future.
Facile direct synthesis of amides from trichloroethyl esters using catalytic DBU
La, Minh Thanh,Kim, Hee-Kwon
, p. 1135 - 1141 (2018/11/25)
A practical method for the direct synthesis of amide compounds is described. Using small quantities of DBU as a catalyst, the direct conversion of 2,2,2-trichloroethyl esters to their corresponding amides was readily achieved. Based on this protocol, various amide compounds were successfully synthesized in high yield, suggesting a promising approach for the practical one-pot aminolysis from 2,2,2-trichloroethyl protected esters.
