In 2014,European Journal of Organic Chemistry included an article by Barroso, Raquel; Escribano, Maria; Cabal, Maria-Paz; Valdes, Carlos. Reference of (S)-N-Methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide. The article was titled 《Tosylhydrazide-Promoted Diastereoselective Intramolecular 1,3-Dipolar Cycloadditions: Synthesis of Tetrahydropyrrolo[3,4-c]pyrazoles》. The information in the text is summarized as follows:
A very straightforward diastereoselective synthesis of tetrahydropyrrolo[3,4-c]pyrazoles by intramol. 1,3-dipolar cycloaddition is described. The starting materials for the synthetic route are N-Boc-protected α-amino acids, which are first transformed into N-allyl-α-amino ketones through conventional methodologies. Then, a one-pot sequence that involves formation of a tosylhydrazone from the ketone, base-induced decomposition of the hydrazone, and intramol. 1,3-dipolar cycloaddition of the diazo compound generated, gives rise to the bicyclic systems with total diastereoselectivity and high preservation of the enantiomeric purity. However, the analogous process employing α-amino aldehydes lacks stereoselectivity. DFT computational modeling has been carried out to account for the different behavior of the two types of systems. In addition to this study using (S)-N-Methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide, there are many other studies that have used (S)-N-Methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide(cas: 87694-50-6Reference of (S)-N-Methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide) was used in this study.
(S)-N-Methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide(cas: 87694-50-6) belongs to amides. Because of the greater electronegativity of oxygen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors.“,” In primary and secondary amides, the presence of N–H dipoles allows amides to function as H-bond donors as well. Reference of (S)-N-Methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide
Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics