17831-01-5Relevant academic research and scientific papers
Transition Metal-Free N-Arylation of Amino Acid Esters with Diaryliodonium Salts
Kervefors, Gabriella,Kersting, Leonard,Olofsson, Berit
, p. 5790 - 5795 (2021/03/08)
A transition metal-free approach for the N-arylation of amino acid derivatives has been developed. Key to this method is the use of unsymmetric diaryliodonium salts with anisyl ligands, which proved important to obtain high chemoselectivity and yields. The scope includes the transfer of both electron deficient, electron rich and sterically hindered aryl groups with a variety of different functional groups. Furthermore, a cyclic diaryliodonium salt was successfully employed in the arylation. The N-arylated products were obtained with retained enantiomeric excess.
MACROCYCLIZATION OF PEPTIDOMIMETICS
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Page/Page column 36; 41-42, (2019/10/19)
The invention provides an improved method of macrocyclization of peptidomimetics, as measured by isolated yields and product distribution, which comprises substitution of one or more of the backbone amide C=O bonds with a turn-inducing motif. The method is general with enhancements seen across a range of ring sizes (e.g. tri-, tetra-, penta- and hexapeptides). Specifically, the invention provides a peptidomimetic macrocycle comprising a carbonyl bioisosteric turn-inducing element having the structure: (I) wherein X is a heteroatom; and wherein R1 to R6 are each independently selected from alkyl, aryl, heteroaryl and H.
NS5B polymerase inhibitor
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Paragraph 0017; 0018, (2017/08/19)
The invention discloses a compound represented by a formula shown in the description, or medicinal salts thereof. The compound has a better hepatitis C treatment effect than sofosbuvir, has similar toxic and side effects with the sofosbuvir, and does not have obvious untoward effects.
A synthetic amino acid N-methylation method and its product and application (by machine translation)
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Paragraph 0053; 0054; 0055, (2016/11/09)
The invention belongs to the technical field of amino acid polypeptide synthesis, discloses a synthetic amino acid N-methylation method and its product and application. This method passes the benzyl protection of a carboxyl group of the amino acid, trifluoroacetyl protection of the amino group, after methylation, get N-methylation of the amino acid. N obtained by the method of this invention-methyl (trifluoro-acetyl)-amino acid benzyl ester, can be directly used for polypeptide synthesis N-methyl structure having the amino acid benzyl ester product, and it has good selective deprotection of, its N the C-end-to-end and selectively deprotected. With foreign Ag 2 O/CH 3 I/Boc method (hypertoxic, high cost) and NaH / (CH 3 O) 2 SO 2 method compared with (hypertoxic), and the like, the method of the invention high yield, the use of the virulent reagent-free, safe and non-toxic, the operation is simple, common reagent to the raw material, the cost is low, and the structure strong pertinence, racemation a low possibility of the product obtained, it has broad industrial prospects. (by machine translation)
Enantioselective synthesis of 1,2,4-triazolines by chiral iron(ii)-complex catalyzed cyclization of α-isocyano esters and azodicarboxylates
Wang, Min,Liu, Xiaohua,He, Peng,Lin, Lili,Feng, Xiaoming
supporting information, p. 2572 - 2574 (2013/04/10)
Enantioselective cyclization of α-isocyano esters with azodicarboxylates catalyzed by FeII-N,N′-dioxide complexes has been developed. Under mild conditions, a variety of 1,2,4-triazoline derivatives was obtained in high yields and enantioselectivities.
In situ deprotection and incorporation of unnatural amino acids during cell-free protein synthesis
Arthur, Isaac N.,Hennessy, James E.,Padmakshan, Dharshana,Stigers, Dannon J.,Lesturgez, Stéphanie,Fraser, Samuel A.,Liutkus, Mantas,Otting, Gottfried,Oakeshott, John G.,Easton, Christopher J.
supporting information, p. 6824 - 6830 (2013/06/26)
The S30 extract from E. coli BL21 Star (DE3) used for cell-free protein synthesis removes a wide range of α-amino acid protecting groups by cleaving α-carboxyl hydrazides; methyl, benzyl, tert-butyl, and adamantyl esters; tert-butyl and adamantyl carboxamides; α-amino form-, acet-, trifluoroacet-, and benzamides and sidechain hydrazides and esters. The free amino acids are produced and incorporated into a protein under standard conditions. This approach allows the deprotection of amino acids to be carried out in situ to avoid separate processing steps. The advantages of this approach are demonstrated by the efficient incorporation of the chemically intractable (S)-4-fluoroleucine, (S)-4,5- dehydroleucine, and (2S,3R)-4-chlorovaline into a protein through the direct use of their respective precursors, namely, (S)-4-fluoroleucine hydrazide, (S)-4,5-dehydroleucine hydrazide, and (2S,3R)-4-chlorovaline methyl ester. These results also show that the fluoroand dehydroleucine and the chlorovaline are incorporated into a protein by the normal biosynthetic machinery as substitutes for leucine and isoleucine, respectively. Copyright
N-aminosulfamide peptide mimic synthesis by alkylation of aza-sulfurylglycinyl peptides
Turcotte, Stephane,Bouayad-Gervais, Samir H.,Lubell, William D.
supporting information; body text, p. 1318 - 1321 (2012/05/20)
N-Aminosulfamides are peptidomimetics in which the CαH and the carbonyl of an amino acid residue are both respectively replaced by a nitrogen atom and a sulfonyl group. Aza-sulfurylglycinyl tripeptide analogs were effectively synthesized from amino acid building blocks by condensations of N-protected amino hydrazides and p-nitrophenylsulfamidate esters. The installation of N-alkyl chains and access to other aza-sulfuryl amino acid residues were effectively achieved by chemoselective alkylation.
Synthesis and RNase A inhibition study of C2-symmetric bis-isochromenyl sulfones
Mitra, Tapobrata,Dutta, Sansa,Basak, Amit
supporting information; experimental part, p. 2828 - 2831 (2010/07/06)
A new class of C2-symmetric bis-isochromene derivatives with 3,3′-linkage has been synthesized from bis-propargyl sulfones. The method involves treatment of the sulfones with triethylamine to form the isochromene derivatives presumably via the intramolecular Michael addition to the intermediate bis-allenic sulfones. Interestingly, the product expected from the Garratt-Braverman pathway was not obtained. The bis-isochromene 7d displayed RNase A inhibition activity, much stronger than the isochromene 8 and bis-isocoumarin 9.
A class of novel conjugates of substituted purine and Gly-AA-OBzl: Synthesis and evaluation of orally analgesic activity
Kang, Guifeng,Zhao, Ming,Zhang, Xiaoyi,Peng, Li,Li, Chunbo,Mao, Wei,Ye, Weidong,Peng, Shiqi
supporting information; experimental part, p. 6157 - 6160 (2010/12/19)
Aimed at the chemotherapy of chronic pain two kinds of analgesic pharmacophores, substituted purine and Gly-AA-OBzl, were coupled via a five-step-reaction procedure and 19 novel conjugates N-[2-chloro-9- (tetrahydropyran-2-yl)-9H-purin-6-yl]-N-cyclopropylglycylamino acid benzylesters were provided. On mouse-tail flick model their in vivo analgesic activities were assayed. The results indicate that introducing Gly-OC2H 5 into the 6-position of the substituted purine leads to ambiguous increase of the analgesic activity, while introducing Gly-AA-OBzl into this position leads to significant increase of the analgesic activity.
Esterification of unprotected a-Amino acids in ionic liquids as the reaction media
Biondini, Daniele,Brinchi, Lucia,Germani, Raimondo,Goracci, Laura,Savelli, Gianfranco
experimental part, p. 39 - 44 (2010/08/22)
Ionic liquid 1,3-dimethylimidazolium methanesulfonate was used to prepare a-amino acids benzylic esters from unprotected amino acids and benzyl chloride. Esterification of several amino acids was achieved with satisfactory yields: by-products can be removed by a simple work-up procedure to afford the pure product. The described method is simple, mild, rapid and save.
