In/Cu Catalyzed Multiple C-N/C-C Bond Formation via Multiple Bond Cleavage in a Three Component Synthesis of Arylimidazopyridine Carboxylates was written by Roslan, Irwan Iskandar;Ng, Kian-Hong;Alhooshani, Khalid R.;Jaenicke, Stephan;Chuah, Gaik-Khuan. And the article was included in Asian Journal of Organic Chemistry in 2021.Electric Literature of C11H20O4 This article mentions the following:
A protocol for In and Cu co-catalyzed synthesis of a wide array of arylimidazopyridine carboxylates I [R1 = Ph, 3-thienyl, 2-naphthyl, etc.; R2 = CN, CO2Me, CO2Et, etc.; R3 = H, 8-Me, 7-OMe, etc.] by three component coupling of aryl aldehydes, malonic esters and 2-aminopyridines was described. The reaction proceeded through a reaction cascade of Knoevenagel condensation, 1,4-conjugate addition, aerobic dehydrogenation, Ortoleva-King reaction and decarboxylation. Multiple C-N and C-C bond formations in addition to multiple C-C, C-H, C-O, and N-H bond cleavages were involved in forming the product. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Electric Literature of C11H20O4).
malonic acid dibutyl ester (cas: 1190-39-2) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Electric Literature of C11H20O4
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics