203116-76-1Relevant academic research and scientific papers
Oxidative amidation and azidation of aldehydes by NHC catalysis
De Sarkar, Suman,Studer, Armido
, p. 1992 - 1995 (2010)
Figure presented N-Heterocyclic carbene catalyzed oxidative amidations of various aldehydes to the corresponding hexafluoroisopropylesters by using the readily available organic oxidant A are described. The hexafluoroisopropylesters prepared in situ are shown to be highly useful active esters for amide bond formation. In addition, oxidative azidation of aldehydes is presented. These mild organocatalytic processes do not use any transition metal.
A Convenient One-Pot Synthesis of 1,5-Disubstituted Tetrazoles Containing an Amino or a Carboxy Group
Obushak, M. D.,Pokhodylo, N. T.,Shyyka, O. Ya.
, p. 802 - 812 (2020/07/03)
Abstract: A convenient method is proposed for constructing the tetrazole ring by a one-pot reaction of amides with phosphorus oxychloride and sodium azide. A series of 1,5-disubstituted tetrazoles containing an amino or a carboxy group, which present interest as buildings blocks for the synthesis of biologically active substances, were obtained.
Solution and solid-state models of peptide CH...O hydrogen bonds
Baures, Paul W.,Beatty, Alicia M.,Dhanasekaran, Muthu,Helfrich, Brian A.,Perez-Segarra, Waleska,Desper, John
, p. 11315 - 11323 (2007/10/03)
Fumaramide derivatives were analyzed in solution by 1H NMR spectroscopy and in the solid state by X-ray crystallography in order to characterize the formation of CH...O interactions under each condition and to thereby serve as models for these interactions in peptide and protein structure. Solutions of fumaramides at 10 mM in CDCl3 were titrated with DMSO-d6, resulting in chemical shifts that moved downfield for the CH groups thought to participate in CH...O=S(CD3)2 hydrogen bonds concurrent with NH...O=S(CD3)2 hydrogen bonding. In this model, nonparticipating CH groups under the same conditions showed no significant change in chemical shifts between 0.0 and 1.0 M DMSO-d6 and then moved upfield at higher DMSO-d6 concentrations. At concentrations above 1.0 M DMSO-d6, the directed CH...O=S(CD3)2 hydrogen bonds provide protection from random DMSO-d6 contact and prevent the chemical shifts for participating CH groups from moving upfield beyond the original value observed in CDCl3. X-ray crystal structures identified CH...O=C hydrogen bonds alongside intermolecular NH...O=C hydrogen bonding, a result that supports the solution 1H NMR spectroscopy results. The solution and solid-state data therefore both provide evidence for the presence of CH...O hydrogen bonds formed concurrent with NH...O hydrogen bonding in these structures. The CH...O=C hydrogen bonds in the X-ray crystal structures are similar to those described for antiparallel β-sheet structure observed in protein X-ray crystal structures.
