THE KOLBE-SCHMITT REACTION. I. VARIATIONS IN THE CARBONATION OF p-CRESOL

Cameron, D. D.; Jeskey, Harold; Baine, Ogden

doi:10.1021/jo01148a002

Cited by 25 publications

(17 citation statements)

References 4 publications

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“…As stated in the introduction, this finding has never been reported in these conditions in the literature. In fact, how this process was typically carried out at 440 K and 10 MPa [ 16 ] and the inhibition effect in the presence of water of the Kolbe–Schmitt carboxylation ( Figure S7 ) [ 54 , 55 , 56 ] by blocking the cation-induced electrophilic replacement in the aromatic ring [ 57 , 58 ] were previously reported. Thus, it is an evidence that phenol conversion is possible due to the characteristics of these hybrid materials as their hydrophobicity (in order to reduce the inhibition effect of water) and surface composition (carbon coating, Fe species, or a mixed site of both should take place as active sites).…”

Section: Resultsmentioning

confidence: 99%

“…Neither double carboxylation nor meta-carboxylation product was detected. The formation of benzoic acid (0–6%), p-hydroxybenzoic (<1%) acid, and salicylic acid (0–10%), which presented an additional carbon in the molecular structure, should be related with the formation of C–C bonds by carboxylation [ 53 , 54 , 55 ]. The C@Al-923 and C@Al-1023 hybrids showed the highest relative amount of salicylic acid among carboxylation products (>90% of C7 compounds).…”

Section: Resultsmentioning

confidence: 99%

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First Phenol Carboxylation with CO2 on Carbon Nanostructured C@Fe-Al2O3 Hybrids in Aqueous Media under Mild Conditions

et al. 2021

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Novel hybrid materials with integrated catalytic properties and hydrophobic response, C@Fe–Al2O3 hybrid samples, were presented and tested as catalysts for phenol reaction in aqueous solutions at atmospheric pressure and mild temperature conditions, using CO2 as a feedstock. A series of carbon-coated γ-alumina pellets (C@Fe–Al2O3) were synthesized and characterized by TGA, Brunauer–Emmett–Teller (BET) method, Raman spectroscopy, SEM, TEM, and XPS in order to get comprehensive knowledge of their properties at the nanoscale and relate them with their catalytic behavior. The results obtained correlated their catalytic activities with their carbon surface compositions. The application of these materials as active catalysts in the Kolbe–Schmitt reaction for CO2 conversion in aqueous media was proposed as an alternative reaction for the valorization of exhausts industrial effluents. In these early tests, the highest conversion of phenol was observed for the hybrid samples with the highest graphitic characteristic and the most hydrophobic behavior. Carboxylation products such as benzoic acid, p-hydroxybenzoic acid, and salicylic acid, have been identified under these experimental conditions.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

First Phenol Carboxylation with CO2 on Carbon Nanostructured C@Fe-Al2O3 Hybrids in Aqueous Media under Mild Conditions

et al. 2021

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“…It was thus mandatory to introduce this substituent already in the starting material, that is, into the meta position of the salicylate. The respective salicylic acid is readily available through a Kolbe–Schmitt reaction, [18] and substrate 4 b (Scheme 2) was synthesized in three steps and an overall yield of 77 % from para ‐cresol (see the Supporting Information). The results of its photochemical reaction were disappointing, however.…”

Section: Figurementioning

confidence: 99%

Concise Access to the Skeleton of Protoilludane Sesquiterpenes through a Photochemical Reaction Cascade: Total Synthesis of Atlanticone C

2019

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In asingle photochemical operation (l ! 350 nm) an easily accessible indanone derivative was converted into as tructurally complex precursor of the protoilludane sesquiterpenes.T he product (60 %y ield) contains all 15 carbon atoms of the skeleton in the required connectivity and was transformed into the natural product atlanticone C( 9s teps, 6% overall yield). In addition, it was shown that other protoilludanes,s uch as D 6 -protoilludene and paesslerin A, can be prepared in aconcise fashion via the photochemical key intermediate.T he photochemical reaction cascade comprises an ortho photocycloaddition, athermal disrotatory ring opening and ar egioselective disrotatory [4p]p hotocyclization.The protiolludane skeleton A (Figure 1) represents an intriguing natural product scaffold and is the hallmark of many biologically active sesquiterpenes.Acentral cyclohexane ring is flanked by ac yclobutane ring with aq uaternary carbon center C-3 and by a gem-dimethyl-substituted cyclopentane ring at positions C-2 and C-9. Thep rotoilludane biosynthesis [1] from farnesyl pyrophosphate via cationic intermediates is testimony to the masterful ability of nature to create molecular complexity from simple building blocks. Representative sesquiterpenes with this structure element include atlanticone C( 1), [2] D 6 -protoilludene (2), [3] and paesslerin A( 3). [4] Many synthetic approaches have been described to tackle the challenging core structure of the protoilludanes. [5] One set of syntheses aimed at ac onstruction of the tricyclic skeleton from acyclic or monocyclic precursors in amanner mimicking their biological genesis from humulene. [6] In several other approaches,t he rings were built consecutively, [7] with the construction of the cyclobutane ring requiring particular attention. Notable photochemical strategies [8] to secure formation of the four-membered ring include the common [2+ +2] photocycloaddition [9] but also some less frequently used methods such as the photochemical 1,3-acyl shift reaction of b,g-unsaturated enones. [10] Our interest in protoilludanes was triggered by recent work [11] on ar eaction cascade [12] that is initiated by an ortho photocycloaddition and that generates the bicyclo[4.2.0]octane skeleton, acore element of structure A,inasingle operation. Herein, we disclose aconcise access to protoilludane sesquiterpenes that culminated in the first total synthesis of atlanticone C( 1)a nd in the stereoselective synthesis of two other advanced intermediates that had been previously converted into D 6 -protoilludene (2)a nd paesslerin A( 3).Arenes B (Scheme 1), which have ac arbonyl group in ortho position to an alkenyloxy group,are known to undergo an initial [2+ +2] photocycloadditon at the arene (ortho photocycloaddition [13,14] ). Products C are unstable and form cyclooctatrienes D through ad isrotatory ring opening.I ns ome cases,t hese products have been isolated [15] but the most frequent reaction pathway is ac onsecutive disrotatory [4p] Figure 1. The protoilludane skeleton A and representa...

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“…Aspirin the most widely used drug, can be synthesized by acetylation reaction of salicylic acid [1] . In 1859, Kolbe and his assistant Schmitt developed the synthesis method of salicylic acid by means of sodium phenoxide and CO 2 at 125 ℃ and 100 atm, named as Kolbe-Schmitt reaction [1][2][3][4][5] . The possible mechanism is as follows: (1) Sodium phenoxide captured CO 2 , then carboxylation reaction occurred to form C(sp 2 )-C(sp 3 ) bond between CO 2 and C atom in phenyl ring, (2) Proton transferred from C(sp 3 ) atom to phenoxide O atom, leading to sodium 4-hydroxybenzoate, which can be easily acidi ed to salicylic acid.…”

Section: Introductionmentioning

confidence: 99%

DFT study on reaction mechanism of di-tert-butylphenol to di-tert-butylhydroxybenzoic acid

et al. 2022

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Experimental studies on the Kolbe-Schmitt reaction and its side reactions have made great progresses, however the relative theoretical studies fall behind. In order to study the mechanism of Kolbe-Schmitt reaction with 2,6-di-tert-butylphenol and 2,4-di-tert-butylphenol as reactants, we carried out theoretical calculation studies at M06-2X/Def2-SVP/SMD level of theory using Gaussian 09 D.01 software package.For the reactant 2,6-di-tert-butylphenol, the main product and side product can convert to each other due to the dynamic equilibrium. However for 2,4-di-tert-butylphenol, the main product is thermodynamically favorable due to its lower Gibbs free energy, while the side product is kinetically favorable due to the lower activation energy barrier. We hope the study can shed light on Kolbe-Schmitt reaction.

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THE KOLBE-SCHMITT REACTION. I. VARIATIONS IN THE CARBONATION OF p-CRESOL

Cited by 25 publications

References 4 publications

First Phenol Carboxylation with CO2 on Carbon Nanostructured C@Fe-Al2O3 Hybrids in Aqueous Media under Mild Conditions

First Phenol Carboxylation with CO2 on Carbon Nanostructured C@Fe-Al2O3 Hybrids in Aqueous Media under Mild Conditions

Concise Access to the Skeleton of Protoilludane Sesquiterpenes through a Photochemical Reaction Cascade: Total Synthesis of Atlanticone C

DFT study on reaction mechanism of di-tert-butylphenol to di-tert-butylhydroxybenzoic acid

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