Rhodium-Catalyzed Additive-Free C-H Ethoxycarbonylation of (Hetero)Arenes with Diethyl Dicarbonate as a CO Surrogate was written by Suzuki, Hirotsugu;Liao, Yumeng;Kawai, Yuya;Matsuda, Takanori. And the article was included in European Journal of Organic Chemistry in 2021.SDS of cas: 4373-61-9 This article mentions the following:
A rhodium-catalyzed C(sp2)-H ethoxycarbonylation of indoles and arylpyridines using di-Et dicarbonate to form indole-2-carboxylic acid esters such as I [X = CH, N; R1 = H, 4-Me, 5-Cl, etc.] and isophthalates II [R2 = H, 5-Me, 5-Ph, etc.; R3 = H, 5-Me, 4-Me] was developed. The catalytic process featured an additive-free ethoxycarbonylation reaction, in which only ethanol and CO2 were produced as byproducts, providing a CO-free and operationally simple protocol. The introduced ethoxycarbonyl group was easily transformed into other ester and amide functionalities in a single step. Moreover, the reaction could be successfully applied on gram scale, and allowed for the efficient synthesis of indole-2-carboxylic acid esters and isophthalates. In the experiment, the researchers used many compounds, for example, 2-(m-Tolyl)pyridine (cas: 4373-61-9SDS of cas: 4373-61-9).
2-(m-Tolyl)pyridine (cas: 4373-61-9) belongs to pyridine derivatives. Pyridine’s the lone pair does not contribute to the aromatic system but importantly influences the chemical properties of pyridine, as it easily supports bond formation via an electrophilic attack. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.SDS of cas: 4373-61-9