Direct Carboxylation of Thiophenes and Benzothiophenes with the Aid of EtAlCl2

Nemoto, Koji; Onozawa, Satoru; Konno, Megumi; Morohashi, Naoya; Hattori, Tetsutaro

doi:10.1246/bcsj.20110335

Cited by 29 publications

(7 citation statements)

References 28 publications

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“…For 1‐unsubstituted indole, the yield was poor. In 2012, they reported similar carboxylation of thiophene and benzothiophene assisted by equimolar amounts of ethylaluminum dichloride . In 2012, Kobayashi and co‐workers reported the carboxylation of unprotected indole derivatives with CO 2 mediated by lithium tert ‐butoxide (Scheme ) .…”

Section: Carboxylation Of C(sp2)−h Bonds With Co2mentioning

confidence: 99%

“…In 2016, based on previous work, Hattori and co‐workers reported a EtAlCl 2 /2,6‐disubstituted pyridine mediated carboxylation of α‐aryl alkenes and trisubstituted alkenes with CO 2 (Scheme ) . In terms of practical yield, this is the first reaction in which a vinyl hydrogen atom is replaced by a carboxyl group.…”

Section: Carboxylation Of C(sp2)−h Bonds With Co2mentioning

confidence: 99%

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C−H Bond Carboxylation with Carbon Dioxide

et al. 2019

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Carbon dioxide is a nontoxic, renewable, and abundant C1 source, whereas C−H bond functionalization represents one of the most important approaches to the construction of carbon–carbon bonds and carbon–heteroatom bonds in an atom‐ and step‐economical manner. Combining the chemical transformation of CO2 with C−H bond functionalization is of great importance in the synthesis of carboxylic acids and their derivatives. The contents of this Review are organized according to the type of C−H bond involved in carboxylation. The primary types of C−H bonds are as follows: C(sp)−H bonds of terminal alkynes, C(sp2)−H bonds of (hetero)arenes, vinylic C(sp2)−H bonds, the ipso‐C(sp2)−H bonds of the diazo group, aldehyde C(sp2)−H bonds, α‐C(sp3)−H bonds of the carbonyl group, γ‐C(sp3)−H bonds of the carbonyl group, C(sp3)−H bonds adjacent to nitrogen atoms, C(sp3)−H bonds of o‐alkyl phenyl ketones, allylic C(sp3)−H bonds, C(sp3)−H bonds of methane, and C(sp3)−H bonds of halogenated aliphatic hydrocarbons. In addition, multicomponent reactions, tandem reactions, and key theoretical studies related to the carboxylation of C−H bonds are briefly summarized. Transition‐metal‐free, organocatalytic, electrochemical, and light‐driven methods are highlighted.

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Section: Carboxylation Of C(sp2)−h Bonds With Co2mentioning

confidence: 99%

Section: Carboxylation Of C(sp2)−h Bonds With Co2mentioning

confidence: 99%

C−H Bond Carboxylation with Carbon Dioxide

et al. 2019

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“…[31] The same treatment of thiophenes and benzothiophenes with EtAlCl 2 under pressurized CO 2 gave the corresponding carboxylic acids in up to 90 %yield. [32] Also, fused-ringaromatic compounds, such as naphthalene, anthracene, and phenanthrene, could undergo Lewis-acid-mediated carboxylation under CO 2 pressure (ca. 30 atm), giving 1-naphthoica cid, 9-anthracenecarboxylic acid, and 9-phenanthrenecarboxylic acid, respectively.…”

Section: Lewis-acid-mediated Carboxylationmentioning

confidence: 99%

C−H Carboxylation of Aromatic Compounds through CO₂ Fixation

2017

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Carbon dioxide (CO2) represents the most abundant and accessible carbon source on Earth. Thus the ability to transform CO2 into valuable commodity chemicals through the construction of C−C bonds is an invaluable strategy. Carboxylic acids and derivatives, the main products obtained by carboxylation of carbon nucleophiles by reaction of CO2, have wide application in pharmaceuticals and advanced materials. Among the variety of carboxylation methods currently available, the direct carboxylation of C−H bonds with CO2 has attracted much attention owing to advantages from a step‐ and atom‐economical point of view. In particular, the prevalence of (hetero)aromatic carboxylic acids and derivatives among biologically active compounds has led to significant interest in the development of methods for their direct carboxylation from CO2. Herein, the latest achievements in the area of direct C−H carboxylation of (hetero)aromatic compounds with CO2 will be discussed.

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“…The direct carboxylation of the carbon–hydrogen (C–H) bonds of arenes and heteroaromatics represents an important and useful synthetic method to access carboxylic acids that may serve as precursors for the preparation of biologically active compounds . The most common strategy toward the chemical fixation of CO 2 with C–H bonds is through transition-metal catalysis, through Lewis-acid-mediated Friedel–Crafts reactions, or by base-mediated carboxylation of aromatic heterocycles . Recently, Hattori successfully employed dialkylaluminum chloride as a Lewis acid mediator for the direct carboxylation of indoles and pyrroles with CO 2 .…”

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confidence: 99%