130622-05-8Relevant academic research and scientific papers
Expedient synthesis of (+)-lycopalhine A
Williams, Benjamin M.,Trauner, Dirk
, p. 2191 - 2194 (2016)
Two amino acids play a key role in the first total synthesis of lycopalhine A. l-glutamic acid serves as a convenient chiral starting material for the 13-step synthesis, and l-proline promotes an unusual 5-endo-trig Mannich cyclization that generates the central pyrrolidine ring of the Lycopodium alkaloid. The bicyclo[3.3.0]octanol moiety of the molecule is formed through an intramolecular aldol addition that may occur spontaneously in nature. Just Another Mannich Monday: By using l-glutamate and l-proline as a starting material and catalyst, respectively, the complex alkaloid lycopalhine A was assembled in only 13 steps. The synthesis features not only an unusual Mannich reaction but also a biomimetic aldol addition that completes the intricate carbon skeleton of the natural product.
Synthesis of 5-Cyano-Tryptophan as a Two-Dimensional Infrared Spectroscopic Reporter of Structure
Chalyavi, Farzaneh,Gilmartin, Philip H.,Schmitz, Andrew J.,Fennie, Michael W.,Tucker, Matthew J.
, p. 7528 - 7532 (2018)
A concise synthesis of protected 5-cyano-l-tryptophan (Trp5CN) has been developed for 2D IR spectroscopic investigations within either peptides or proteins. To assess the potential of differently substituted cyano-tryptophans, several model cya
Synthesis of cis -5-trifluoromethylproline from l -glutamic acid
Ortial, Stéphanie,Dave, Rajesh,Benfodda, Zohra,Bénimélis, David,Meffre, Patrick
, p. 569 - 573 (2014)
The diastereoselective synthesis of cis-5-trifluoromethylproline (5-Tfm-Pro) from l-glutamic acid is described. 5-Tfm-Pro could be obtained through a seven-step linear sequence. Trifluoromethylation of the glutamic-derived ester or aldehyde and subsequent reduction of the cyclic imine are the key steps in the synthesis. Georg Thieme Verlag Stuttgart New York.
New reaction conditions using trifluoroethanol for the E-I Hofmann rearrangement
Matsumura, Yoshihiro,Yuki Satoh, Kimihiro Shirai,Onomura, Osamu,Toshihide, Maki
, p. 2057 - 2060 (1999)
The Hofmann rearrangement of -protected glutamine esters to N2-protected (2S)-4-[(2,2,2-trifluoroethoxy)carbonyIamino]-2-aminobutyric acid esters was successfully achieved by an electrochemical method using a trifluoroethanol (TFE)-MeCN solvent system where the TFE may play an important role in controlling the basicity caused by electrochemically generated bases.
A practical and efficient synthesis of thalidomide via Na/liquid NH 3 methodology
Varala, Ravi,Adapa, Srinivas R.
, p. 853 - 856 (2005)
A facile, efficient, concise, cost-effective, and scalable synthesis of thalidomide in high overall yield (55%) is presented. Treatment of Boc-protected L-glutamic acid diester via Na/ liquid (liq.) NH3 (-33°C) mediated cyclization methodology produces a corresponding glutarimide ring which was subsequently condensed with phthalic anhydride in the presence of glacial acetic acid to afford thalidomide.
Enantiospecific synthesis of α-amino acid semialdehydes: A key step for the synthesis of unnatural unsaturated and saturated α-amino acids
Padron, Jose M.,Kokotos, George,Martin, Tomas,Markidis, Theodoros,Gibbons, William A.,Martin, Victor S.
, p. 3381 - 3394 (1998)
The enantiospecific synthesis of unnatural unsaturated and saturated α- amino acids based on a Wittig type reaction is described. The versatile synthetic intermediates, L-glutamic and L-aspartic acid semialdehydes, are obtained from the corresponding N,N-di-Boc-diesters, by the selective reduction of the ω-ester with DIBAL under controlled conditions. The semialdehydes are chemically stable for a prolonged time and react with various phosphorous ylides, under controlled conditions, to produce the enantiomerically pure unsaturated α-amino acids in high yields. The method is equally applicable to homologated diesters obtained by the presented methodology providing unsaturated amino acids with variable unsaturated- positions and geometries. The corresponding saturated products can be obtained by simple hydrogenation.
Efficient and selective cleavage of the t-butoxycarbonyl group from di-t-butylimidodicarbonate using catalytic bismuth(III) bromide in acetonitrile
Zheng, Jianlong,Yin, Biaolin,Huang, Wenming,Li, Xiaopeng,Yao, Hequan,Liu, Zhaogui,Zhang, Jiancun,Jiang, Sheng
, p. 5094 - 5097 (2009)
Di-t-butylimidodicarbonates can be chemoselectively and efficiently deprotected to the corresponding mono-BOC-protected amines in high yields using a catalytic amount of bismuth(III) bromide in acetonitrile at room temperature. This method is mild and compatible with the presence of a wide range of functional and other protecting groups in the substrates, such as TBDMS, MOM and mono-BOC or Cbz-protected amines, etc. The method has advantages of ease of operation and use of nontoxic and inexpensive catalyst.
Selenolysine: A New Tool for Traceless Isopeptide Bond Formation
Dardashti, Rebecca Notis,Kumar, Shailesh,Sternisha, Shawn M.,Reddy, Post Sai,Miller, Brian G.,Metanis, Norman
, p. 4952 - 4957 (2020)
Despite their biological importance, post-translationally modified proteins are notoriously difficult to produce in a homogeneous fashion by using conventional expression systems. Chemical protein synthesis or semisynthesis offers a solution to this problem; however, traditional strategies often rely on sulfur-based chemistry that is incompatible with the presence of any cysteine residues in the target protein. To overcome these limitations, we present the design and synthesis of γ-selenolysine, a selenol-containing form of the commonly modified proteinogenic amino acid, lysine. The utility of γ-selenolysine is demonstrated with the traceless ligation of the small ubiquitin-like modifier protein, SUMO-1, to a peptide segment of human glucokinase. The resulting polypeptide is poised for native chemical ligation and chemoselective deselenization in the presence of unprotected cysteine residues. Selenolysine's straightforward synthesis and incorporation into synthetic peptides marks it as a universal handle for conjugating any ubiquitin-like modifying protein to its target.
Preparation of a metal-ligand fluorescent chemosensor and enantioselective recognition of carboxylate anions in aqueous solution
Chen, Zhi-hong,He, Yong-bing,Hu, Chen-Guang,Huang, Xiao-huan
, p. 2051 - 2057 (2008)
Two chiral fluorescent chemosensors 1 and 2 were synthesized, and the structure characterized by IR, 1H NMR, 13C NMR, MS spectra and elemental analysis. Their recognition ability was studied in aqueous solution (Tris-HCl buffer pH 7.4, MeOH/H2O = 1:1) through fluorescence spectra. Receptors 1 and 2 showed a good binding ability to the copper ion. The host 1-Cu2+ complex showed a chiral recognition ability to mandelate anions with a preferable binding to l-mandelate than d-mandelate anions. The host 1-Cu2+ complex and l- or d-mandelate anions formed 1:1 stoichiometric complex. The binding constant for l-mandelate is 576 M-1, whereas that for d-mandelate is only 38 M-1, which can be distinguished by the different change of fluorescence intensity.
Total synthesis of argyrins A and e
Wu, Wenbin,Li, Zheng,Zhou, Guangbiao,Jiang, Sheng
, p. 2488 - 2491 (2011)
The total synthesis of argyrins A and E were accomplished using a convergent strategy by condensation of one tripeptide and two dipeptide fragments. The synthesis strategy, which was developed for the protection of peptide fragments and identification of the optimum macrocylization site, can be applied to further synthetic studies involving other members of the argyrin family.
