2867-06-3Relevant articles and documents
Facile and purification free synthesis of peptides utilizing ROMPgel- and ROMPsphere-supported coupling reagents
Barrett, Anthony G.M.,Bibal, Brigitte,Hopkins, Brian T.,K?bberling, Johannes,Love, Andrew C.,Tedeschi, Livio
, p. 12033 - 12041 (2005)
5-Norbornene-2-carboxaldehyde and norbornadiene were respectively converted into norbornene derivatives functionalized with fluoroformamidinium hexafluorophosphate and 2-bromo-N-methylpyridinium tetrafluoroborate residues. Both these norbornene monomers were ring opening metathesis polymerized or graft copolymerized onto polystyrene cores to produce ROMPgel and ROMPsphere peptide-coupling reagents. These were used to prepare hindered amides, dipeptides and tripeptides with minimal purification in parallel arrays.
PEPTIDE SYNTHESIS BY USING N-ACYLPHOSPHORAMIDITES
Kawanobe, Wataru,Yamaguchi, Kazuo,Nakahama, Seiichi,Yamazaki, Noboru
, p. 825 - 828 (1982)
New trivalent phosphorus compounds, N-acetyl-N-methylphosphoramidites were prepared readily in good yield by the reaction of phosphorous chlorides and N-methylacetamide.By using the phosphoramidites as condensing agents, Young's peptide and prolyl-leucyl-
Asymmetric alcoholysis of 2-phenyl-5(4H)-oxazolones by the catalytic mixture of cyclo[(S)-His-(S)-Phe] with chiral auxiliaries
Xie, Lunjia,Hua, Wenting,Chan, Albert S. C.,Leung, Yun-Chang
, p. 4715 - 4728 (1999)
Some derivatives of dipeptides containing a His residue catalyzed the ring opening of 2-phenyl-4-benzyl-5(4H)-oxazolone by methanol. The mixture of cyclo[(S)-His-(S)-Phe] (CHP) with chiral auxiliaries which possess both a hydrogen-bond donor and a hydroge
PROCESS FOR LARGE SCALE LIQUID PHASE SYNTHESIS OF CARBETOCIN AND ITS NOVEL INTERMEDIATES
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Page/Page column 21; 22, (2017/11/06)
A process for large scale liquid phase synthesis of Carbetocin is disclosed. Novel intermediates of formula (A), formula (B), and processes for their preparation are also disclosed.
Organophosphorus esters of 1-hydroxy-2-phenylbenzimidazole: Synthesis and utilization as novel peptide coupling reagents
Kokare, Nagnnath D.,Nagawade, Rahul R.,Rane, Vipul P.,Shinde, Devanand B.
, p. 766 - 772 (2008/01/04)
Highly efficient coupling reagents - phosphoric acid diethyl ester 2-phenylbenzimidazol-1-yl ester, diphenylphosphinic acid 2-phenylbenzimidazol-1- yl ester and phosphoric acid diphenyl ester 2-phenylbenzimidazol-1-yl ester - were designed, synthesized and successfully applied in peptide coupling reactions. Their efficiency was evaluated through the synthesis of a range of amides and peptides, and the extent of racemization was studied by HPLC and found to be negligible. The mechanism of action is probably similar to those found for organophoshorus esters of hydroxybenzotriazole: a presumption supported by the isolation and characterization by mass spectrometry and 1H NMR of some of the proposed intermediates. Georg Thieme Verlag Stuttgart.
Circular dichroism studies on absolute configuration assignment of peptidomimetics with a terminal chiral 3-arylpropionic acid unit
Frelek, Jadwiga,Fryszkowska, Anna,Kwit, Marcin,Ostaszewski, Ryszard
, p. 2469 - 2478 (2007/10/03)
The relationship between the molecular structure of peptidomimetics 1 and their chiroptical properties has been studied using circular dichroism spectroscopy. It was demonstrated that the sign of the Cotton effects occurring around 230 and 270 nm enables the direct assignment of stereochemistry at C-1 and C-3 carbon atoms. The TD-DFT calculations of the circular dichroism (CD) spectrum of one of the model compounds confirm the absolute stereochemistry assignment made experimentally. Thus, CD spectroscopy proved to be a simple, reliable and general tool for the determination of the absolute configuration of the stereogenic centers of peptidomimetics with a terminal 3-arylpropionic group.
A new method for the synthesis of carboxamides and peptides using 1,1′-carbonyldioxydi[2(1H)-pyridone] (CDOP) in the absence of basic promoters
Shiina, Isamu,Kawakita, Yo-Ichi
, p. 1951 - 1955 (2007/10/03)
Various carboxamides or peptides are synthesized from the corresponding carboxylic acids and amines or α-amino acids using 1,1′-carbonyldioxydi[2(1H)-pyridone]. The reaction proceeds in the absence of basic promoters such as triethylamine or 4-(dimethylamino)pyridine, therefore, the undesired racemization does not occur at all in the segment coupling producing Z-Gly-Phe-Val-OMe and Z-Phe-Val-Ala-OMe.
New system for peptide synthesis using N-acylpyrazoles
Kashima, Choji,Tsuruoka, Shiro,Mizuhara, Saori
, p. 413 - 424 (2007/10/03)
New system of peptide synthesis was described. The extension of one amino acid unit on the peptide chain was constituted from only 2 reaction steps, the conversion from esters to the corresponding N-acylpyrazoles and the subsequent aminolysis with amino esters. This new system was distinctive from the conventional peptide synthesis, which was consisted of 3 steps of the deprotection, the activation and the condensation. Moreover, the key intermediate N-acylpyrazoles exhibited the excellent properties of high sensitivity and separability for the chiral column on HPLC using the UV detector.
A convenient method for the preparations of carboxamides and peptides by using di(2-pyridyl) carbonate and O,O′-di(2-pyridyl) thiocarbonate as dehydrating reagents
Shiina,Suenaga,Nakano,Mukaiyama
, p. 2811 - 2818 (2007/10/03)
Preparations of carboxamides and peptides are performed in high yields from free carboxylic acids and amines by dehydration condensation using di(2-Pyridyl) carbonate (DPC) or O,O′-Di(2-Pyridyl) thiocarbonate (DPTC) in the presence of a catalytic amount of 4-(dimethylamino)pyridine (DMAP). The formation of 2-Pyridyl esters, key intermediates of the reaction, from carboxylic acids by using DPC proceeded faster than by using DPTC; therefore, the former carbonate is more efficiently employed in the above condensation reactions.
Preparation of carboxamides via carboxylic-phosphoric anhydrides
Gaede, Bruce
, p. 92 - 93 (2013/09/08)
A number of reagents used to prepare carboxamides via a carboxylic-phosphoric anhydride intermediate have been reexamined. It was found that a simple carboxylic-phosphoric anhydride prepared from a carboxylic acid and commercially available diethyl chlorophosphate provided several significant advantages over more complex intermediates in many cases.
