1676-81-9Relevant articles and documents
Synthesis and in vitro activity towards Mycobacterium tuberculosis of L-serinyl ester and amino derivatives of pyrazinoic acid
Pinheiro, Alessandra C.,Kaiser, Carlos R.,Lourenco, Maria C.S.,De Souza, Marcus V. N.,Wardell, Solange M.S.V.,Wardell, James L.
, p. 180 - 184 (2007)
Reactions between either L-serine methyl ester hydrochloride (1), or the cbz derivative, methyl (S)-(+)-2-(benzyloxycarbonylamino)-3-hydroxypropanoate (2), and pyrazinoyl chloride (3), have been studied. Methyl (S)-(+)-2- benzyloxycarbonylamino-3-[(pyrazinecarbonyl)oxy]propionate (4), methyl (S)-(+)-3-hydroxy-2-[(pyrazine-2-carbonyl) aminolpropionoate (7), methyl 2-[(pyrazinecarbonyl)amino]acrylate (8) were obtained. Additional products, methyl (S)-(+)-2-benzyloxycarbonylamino-3-formyloxypropionoate (5) and methyl (R)-(+)-2-benzyloxycarbonylamino-3-chloropropionoate (6), were isolated from reaction of 2 with 3, in the presence of DMF remaining from the preparation of 3, from pyrazinecarboxylic acid. The coupling of pyrazinecarboxylic acid with 1, in the presence of DCC was prevented by the formation of the unreactive adduct between DCC and pyrazinoic acid. The compounds were tested against M. tuberculosis: compounds (8) and (6) exhibited a MIC (μg/ml) value of 50 and 100, respectively, compared to the MIC value of 100 for the first line TB drug, pyrazinamide. The confirmation of the structure of (8) was obtained via X-ray crystallography.
Glycosylated tris-bipyridine ferrous complexes as molecular mimics of densely packed glycoclusters on cell surfaces: spatial carbohydrate packing of glycoclusters changes on additions of salts
Chigira, Naoto,Maeda, Nao,Tachikawa, Kanako,Sekiguchi, Maki,Amano, Yoshitsugu,Inokuchi, Mayu,Li, Qintong,Hasegawa, Teruaki
, p. 246 - 267 (2019)
Tris-bipyridine ferrous complexes having β-lactosides, β-maltosides or α-mannosides with serinol spacers were prepared as molecular mimics of densely packed carbohydrate clusters on cell surfaces. Conformational analysis on these glycosylated complexes we
On the mechanism of oxazoline-directed metalations: Evidence for nitrogen-directed reactions
Sammakia, Tarek,Latham, Hallie A.
, p. 1629 - 1635 (1996)
We recently described a method for the synthesis of ferrocene complexes possessing planar chirality which relies on the asymmetric deprotonation of chiral ferrocenyloxazolines. The unexpected stereochemical outcome of these reactions led us to examine whether the metalation is directed by the oxygen or the nitrogen of the oxazoline. In this paper, we describe the synthesis of a constrained ferrocenyloxazoline (compound 13) in which oxygen- and nitrogen-directed metalations provide different stereochemical outcomes. Our results show that nitrogen is responsible for the directive effects of the oxazoline when alkyllithium reagents are used to deprotonate the ferrocene. The implications of this result on the origin of asymmetric induction in the metalation of the unconstrained ferrocenyloxazolines 19 and 20 are discussed.
Green Esterification of Carboxylic Acids Promoted by tert-Butyl Nitrite
Cheng, Xionglve,Jiang, Gangzhong,Li, Xingxing,Tao, Suyan,Wan, Xiaobing,Zhao, Yanwei,Zheng, Yonggao
supporting information, p. 2713 - 2718 (2021/06/25)
In this work, the green esterification of carboxylic acids promoted by tert-butyl nitrite has been well developed. This transformation is compatible with a broad range of substrates and exhibits excellent functional group tolerance. Various drugs and substituted amino acids are applicable to this reaction under near neutral conditions, with good to excellent yields.
Me3SI-promoted chemoselective deacetylation: a general and mild protocol
Gurawa, Aakanksha,Kashyap, Sudhir,Kumar, Manoj
, p. 19310 - 19315 (2021/06/03)
A Me3SI-mediated simple and efficient protocol for the chemoselective deprotection of acetyl groups has been developedviaemploying KMnO4as an additive. This chemoselective deacetylation is amenable to a wide range of substrates, tolerating diverse and sensitive functional groups in carbohydrates, amino acids, natural products, heterocycles, and general scaffolds. The protocol is attractive because it uses an environmentally benign reagent system to perform quantitative and clean transformations under ambient conditions.
An efficient, stereocontrolled and versatile synthetic route to bicyclic partially saturated privileged scaffolds
Bond, Andrew D.,Hanby, Abigail R.,King, Thomas A.,Moss, Thomas A.,Sore, Hannah F.,Spring, David R.,Stewart, Hannah L.
supporting information, p. 6818 - 6821 (2020/07/04)
Herein, we describe the development of a simple, high yielding and stereocontrolled strategy for the synthesis of a series of triazolopiperazines and other biologically relevant fused scaffolds from optically active amino acids. This route was applied to the synthesis of 22 scaffolds containing new, previously inaccessible vectors and used to access a novel analogue of ganaplacide.
TOLL-LIKE RECEPTOR LIGANDS
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Paragraph 00316, (2019/08/29)
Toll-like receptor (TLR) ligands having an allose-based core are stable in aqueous formulation and are useful in treating, preventing, or reducing susceptibility to diseases or conditions mediated by TLRs, such as cancer, infectious disease, allergy, autoimmune disease, sepsis, and ischemia reperfusion.
Simple and Practical Real-Time Analysis of Solid-Phase Reactions by Thin-Layer Chromatography
Wu, Chia-Hui,Chen, Chun C.,Lin, Su-Ching,Wang, Cheng-Chung
supporting information, p. 1430 - 1436 (2018/05/15)
Solid-phase synthesis is a practical approach for simplifying the time-consuming and routine purification steps in the preparation of numerous naturally occurring molecules; however, studying such reactions is difficult due to the lack of a convenient monitoring method. By using thin-layer chromatography in conjunction with a photolabile linker on a resin, we developed a convenient and simple method for monitoring solid-phase reactions in real time by thin-layer chromatography. This method provides a user-friendly protocol for examining reaction conditions for solid-state syntheses.
Total Synthesis of Ecumicin
Hawkins, Paige M. E.,Giltrap, Andrew M.,Nagalingam, Gayathri,Britton, Warwick J.,Payne, Richard J.
supporting information, p. 1019 - 1022 (2018/02/23)
The first total synthesis of the potent anti-mycobacterial cyclic depsipeptide natural product ecumicin is described. Synthesis was achieved via a solid-phase strategy, incorporating the synthetic non-proteinogenic amino acids N-methyl-4-methoxy-l-tryptophan and threo-β-hydroxy-l-phenylalanine into the growing linear peptide chain. The synthesis employed key on-resin esterification and dimethylation steps as well as a final macrolactamization between the unusual N-methyl-4-methoxy-l-tryptophan unit and a bulky N-methyl-l-valine residue. The synthetic natural product possessed potent antimycobacterial activity against the virulent H37Rv strain of Mycobacterium tuberculosis (MIC90 = 312 nM).
Solution-phase automated synthesis of an α-amino aldehyde as a versatile intermediate
Masui, Hisashi,Yosugi, Sae,Fuse, Shinichiro,Takahashi, Takashi
supporting information, p. 106 - 110 (2017/02/15)
A solution-phase automated synthesis of the versatile synthetic intermediate, Garner's aldehyde, was demonstrated. tert-Butoxycarbonyl (Boc) protection, acetal formation, and reduction of the ester to the corresponding aldehyde were performed utilizing our originally developed automated synthesizer, ChemKonzert. The developed procedure was also useful for the synthesis of Garner's aldehyde analogues possessing fluorenylmethyloxycarbonyl (Fmoc) or benzyloxycarbonyl (Cbz) protection.