Direct Carboxylation of Electron-Rich Heteroarenes Promoted by LiO-tBu with CsF and [18]Crown-6 was written by Shigeno, Masanori;Hanasaka, Kazuya;Sasaki, Keita;Nozawa-Kumada, Kanako;Kondo, Yoshinori. And the article was included in Chemistry – A European Journal in 2019.Safety of Methyl benzofuran-2-carboxylate This article mentions the following:
The combination of LiO-tBu, CsF, and [18]crown-6 efficiently promoting the direct C-H carboxylation of electron-rich heteroarenes (benzothiophene, thiophene, benzofuran, and furan derivatives) I (R = Me, CN, Br, MeO, Cl, F; R1 = H, CH3, Br) and II (R2 = Br, C6H5, C(O)C6H5, etc.; R3 = H; R2R3 = CH=CH-CH=CH; X = O, S) has been demonstrated. A variety of functional groups, including Me, methoxy, halo, cyano, amide, and keto moieties, is compatible with this system. The reaction proceeds via the formation of a tert-Bu carbonate species. In the experiment, the researchers used many compounds, for example, Methyl benzofuran-2-carboxylate (cas: 1646-27-1Safety of Methyl benzofuran-2-carboxylate).
Methyl benzofuran-2-carboxylate (cas: 1646-27-1) belongs to benzofurans derivatives. Benzofurans are only weakly aromatic in nature and they are cleaved by many oxidative and reductive conditions. Benzofurans have also made significant and distinctive contributions to biology. They exhibit several biological activities that range from antiviral, antimicrobial, antitumor, anti-inflammatory.Safety of Methyl benzofuran-2-carboxylate
Referemce:
Benzofuran – Wikipedia,
Benzofuran | C8H6O – PubChem