43008-70-4Relevant academic research and scientific papers
Chalcogen bonding mediates the formation of supramolecular helices of azapeptides in crystals
Cao, Jinlian,Jiang, Yun-Bao,Li, Zhao,Shi, Di,Weng, Peimin,Yan, Xiaosheng
supporting information, p. 6397 - 6401 (2021/08/03)
To explore whether chalcogen bonding was able to drive the formation of supramolecular helices, alanine-based azapeptides containing a β-turn structure, with a thiophene group, respectively, incorporated in theN- orC-terminus, were employed as helical building blocks. While the former derivative formed a supramolecularM-helixviaintermolecular S?S chalcogen bonding in crystals, the latter formedP-helixviaintermolecular S?O chalcogen bonding.
Enantioselective benzoylation of α-amino esters using (S)-1-benzoyl-2-(α-acetoxyethyl)benzimidazole, a chiral benzimidazolide
Karnik, Anil V.,Kamath, Suchitra S.
, p. 7435 - 7438 (2008/02/11)
(Chemical Equation Presented) A new chiral benzimidazolide is developed as a nonenzymatic acylating agent for enantioselective benzoylation of racemic α-amino esters. The process is highly efficient, which exhibits uniformly high enantioselectivity for α-amino esters with or without aryl substituents under mild reaction conditions. The chiral benzimidazolide is inexpensive and is easily accessible.
Enantioselective enolate protonation: Matching chiral aniline and substrate acidity
Vedejs,Kruger,Suna
, p. 7863 - 7870 (2007/10/03)
A comparison of chiral anilines 1a-f in the asymmetric protonation of enolate 15 shows that the optimum ΔpK(a) value (chiral acid vs protonated enolate) for the highest enantioselectivity is ca. 3 (Table 2). An extension of this concept to amino acid enolates was possible, and 1e was found to give the best enantioselectivity (85% ee) with the alanine-derived N-lithioenolate 5a (Table 3). Changes in aniline pK(a) due to variation of substituents at the aniline nitrogen were evaluated briefly, but these changes did not show consistent trends in the enantioselectivity vs pK(a).
