Transition-metal free oxidative carbo-carboxylation of alkenes with formate in air

Abstract

A synthetic route to oxindole-3-acetic acid derivatives with carbon substituents at C-3 position is disclosed through transition-metal free carbo-carboxylation reaction with CO2•− as the C1 source in-situ generated from formate...

Recent Advances in Reactions Involving Carbon Dioxide Radical Anion

“…Recently, Zhu’s group developed a synthetic route to oxindole-3-acetic acid derivatives through a transition-metal free carboxylation reaction (Scheme ). In this reaction, CO 2 •– performed as a C1 source generated in situ from formate under photoinduced conditions. Furthermore, air was utilized as the oxidant to realize this direct aryl C–H activation, obviating the use of organo (pseudo)­halides as the substrates.…”

“…Recently, Zhu's group developed a synthetic route to oxindole-3-acetic acid derivatives through a transition-metal free carboxylation reaction (Scheme 39). 57 In this reaction, CO 2…”

Carbon Dioxide Radical Anion by Photoinduced Equilibration between Formate Salts and [11C, 13C, 14C]CO2: Application to Carbon Isotope Radiolabeling

“…A series of reports have shown improvement of the conditions, but the high reduction potential of CO 2 [ E 0 = −2.21 V vs a saturated calomel electrode (SCE) in DMF] renders this transformation challenging. , A significant step forward toward the mild formation of CO 2 •– was achieved from formate salts through a hydrogen atom transfer (HAT) . This strategy was popularized in 2021 by the groups of Wickens, Jui, and Li, who recognized that access to CO 2 •– was possible starting from formate salts under photocatalytic conditions. − The radical anion was further engaged as a nucleophilic carbon-radical in Giese-type reactions …”

γ-Butyrolactone Synthesis from Allylic Alcohols Using the CO2 Radical Anion

“…In comparison to the electrophilicity of CO 2 , CO 2 •– is a significantly nucleophilic intermediate. It is typically formed through the process of single-electron reduction of CO 2 through electrochemical − or photochemical − methods, as well as through hydrogen-atom cleavage from the corresponding metal formates (H–CO 2 M; M = alkali metal) under photocatalytic conditions. − Recently, CO 2 •– was also reported to be generated from oxalic acid under photoredox conditions …”