In 2017,Tang, Mi; Sun, Rengwei; Li, Hao; Yu, Xinhong; Wang, Wei published 《An Unconventional Redox Cross Claisen Condensation-Aromatization of 4-Hydroxyprolines with Ketones》.Journal of Organic Chemistry published the findings.HPLC of Formula: 71432-55-8 The information in the text is summarized as follows:
Reaction of α-amino acids, particularly prolines and their derivatives with carbonyl compounds via decarboxylative redox process, is a viable strategy for synthesis of structurally diverse nitrogen centered heterocyclics. In these processes, the decarboxylation is the essential driving force for the processes. The realization of the redox process without decarboxylation may offer an opportunity to explore new reactions. Herein, we report the discovery of an unprecedented redox Claisen-type condensation aromatization cascade reaction of 4-substituted 4-hydroxyproline and its esters with unreactive ketones. We found that the use of propionic acid as a catalyst and a co-solvent can change the reaction course. The commonly observed redox decarboxylation and aldol condensation reactions are significantly minimized. Moreover, unreactive ketones can effectively participate in the Claisen condensation reaction. The new reactivity enables a redox cyclization via an unconventional Claisen-type condensation reaction of in situ formed enamine intermediates from ketone precursors with 4-substituted 4-hydroxyproline and its esters as electrophilic acylation partners. Under the reaction conditions, the cascade process proceeds highly regio- and stereoselectively to afford highly synthetically and biol. valued cis-2,3-dihydro-1H-pyrrolizin-1-ones with a broad substrate scope in efficient ‘one-pot’ operation, whereas such structures generally require multiple steps. The experimental part of the paper was very detailed, including the reaction process of tert-Butyl N,N’-diisopropylcarbamimidate(cas: 71432-55-8HPLC of Formula: 71432-55-8)
tert-Butyl N,N’-diisopropylcarbamimidate(cas: 71432-55-8) belongs to anime. The methylamines occur in small amounts in some plants. Many polyfunctional amines (i.e., those having other functional groups in the molecule) occur as alkaloids in plants—for example, mescaline, 2-(3,4,5-trimethoxyphenyl)ethylamine; the cyclic amines nicotine, atropine, morphine, and cocaine; and the quaternary salt choline, N-(2-hydroxyethyl)trimethylammonium chloride, which is present in nerve synapses and in plant and animal cells.HPLC of Formula: 71432-55-8
Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics