95205-15-5Relevant academic research and scientific papers
An aryne-based three-component access to α-aroylamino amides
Serafini, Marta,Griglio, Alessia,Viarengo, Sara,Aprile, Silvio,Pirali, Tracey
supporting information, p. 6604 - 6612 (2017/08/16)
Aryne chemistry has recently received widespread attention and isocyanides have been reported as efficient nucleophilic partners in a set of multicomponent transformations. In this study, we demonstrate that tertiary α-monosubstituted α-isocyanoacetamides are efficaciously coupled with water and benzyne to offer a direct and metal-free access to densely functionalized α-benzoylamino amides, without competing with the intramolecular cyclization to 5-aminooxazoles. Despite the formation of the aryl anion as a key intermediate, the reaction displays a stereoconservative course, allowing for the preparation of enantiomerically pure α-benzoylamino amides. Finally, the synthetic utility of the reported MCR was exemplified by the preparation of proglumide, a cholecystokinin antagonist.
NITROSATION OF PEPTIDE BONDS. CLEAVAGE OF NITROSATED PEPTIDES BY PYRROLIDINE AND α-AMINO ESTERS
Garcia, Jordi,Gonzalez, Javier,Segura, Ramon,Vilarrasa, Jaume
, p. 3121 - 3128 (2007/10/02)
The reaction of several α-amino acids and peptides (containing Gly, L-Ala, L-Leu, L- or DL-Phe, and/or L- or D-Val) with air-diluted nitrogen oxides has been studied to roughly mimic the N-nitrosation of peptide bonds that the contaminated urban air might produce in pulmonary tissues. Most N-protected α-amino acids give practically quantitative yields of N-nitroso derivatives. N-Protected dipeptides afford either dinitrosated peptides, mixtures of di- and mononitrosated compounds, selectively mononitrosated products, or no reaction at all, depending mainly on steric effects. The same trends are observed for some higher peptides.The (poly)nitrosated peptides, which retain the chirality of the starting materials, have been characterized by 1H and 13C NMR spectroscopy and are cleaved by pyrrolidine and amino esters under mild conditions to give (new) amides or peptides plus diazo derivatives.
