Carboxylation of alkali metal phenoxide with carbon dioxide at terrestrial temperature

Kosugi, Yoshio; Rahim, Md. Abdur; Takahashi, Kazufumi; Imaoka, Yoshio; Kitayama, Masaya

doi:10.1002/1099-0739(200012)14:12<841::aid-aoc74>3.0.co;2-p

Cited by 24 publications

(9 citation statements)

References 6 publications

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“…Ovakav zaključak je u saglasnosti sa rezultatima Rahim i sar. koji su pokazali da je obrazovanje intermedijera B kompetitivno reakciji karboksilacije [8,9]. Pošto se Kolbe-Schmitt reakcija odvija na povišenim temperaturama, nagrađeni kompleks B se raspada na polazna jedinjenja koja dalje podležu reakciji karboksilacije.…”

Section: Rezultati I Diskusijaunclassified

“…Kolbe-Schmitt reakcija je reakcija karboksilacije fenoksida i naftoksida alkalnih i zemnoalkalnih metala, u kojoj nastaju aromatične hidroksi kiseline [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Proizvodi Kolbe-Schmitt reakcije imaju značajnu industrijsku ulogu u sintezi brojnih jedinjenja kao što su farmaceutski preparati i akivne supstance, antiseptici, fungicidi, insekticidi i razvijači boja, zatim u tekstilnoj industriji, proizvodnji poliestara i visoko polimerizovanih tečnih kristala, itd.…”

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“…Sa druge strane, Rahim i sar. predložili su mehanizam direktne karboksilacije koji podržavaju brojni eksperimenti [9][10][11]. Oni su potvrdili nastajanje intermedijernog kompleksa, koji, međutim, ne reaguje dalje do aromatičnih hidroksi kiselina, već se raspada do fenoksida ili naftoksida.…”

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Carboxylation of sodium 2-naphthoxide. Reinvestigation of the mechanism by means of a hybrid meta density functional theory method

Djurovic

Marković

Markovic

2015

Hem Ind

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Aromatic hydroxy acids, the compounds of large industrial importance, can be prepared in the Kolbe-Schmitt reaction, i.e. a carboxylation reaction of alkali metal phenoxides (MOPh) and naphthoxides (MONaph). On the basis of the experimental results two contradictory reaction mechanisms have been proposed: the one of direct carboxylation, and the other involving initial formation of the MOPh-CO2 or MONaph-CO2 complex. Previous theoretical investigations of the carboxylation reaction of sodium 2-naphthoxide, performed by means of the B3LYP method, confirmed the initial formation of the NaONaph-CO2 complex, and showed that the carbon of the CO2 moiety performs an electrophilic attack at C1 of the ring, leading to the formation of sodium 2-hydroxy-1-naphthoate (E1). Surprisingly, transition states for possible electrophilic attacks at C3 and C6 were not revealed, and the formation of other two products (E3 and E6) was explained by a number of consecutive rearrangements. In addition, this mechanism includes a reaction step with rather high activation energy. Since more sophisticated functionals are today available, the aim of this work is to reinvestigate the mechanism of the Kolbe-Schmitt reaction of NaONaph in all three positions (1, 3, and 6). Our investigations with the M062X method demonstrated that CO2 and NaONaph can spontaneously build two complexes: B (the one previously reported) and C. While B cannot be further transformed to yield the reaction products, the CO2 moiety in C takes perfect position for electrophilic attacks at all three sites of the ring. These attacks are realized via the transition states TS1, which lead to the formation of the new C-C bonds, and corresponding intermediates D. In the next, bimolecular reaction step two D intermediates exchange the protons adjacent to the CO2 groups. These intermolecular reaction steps require significantly lower activation energies in comparison to the intramolecular proton shift from C to O. The carboxylation reaction in the position 6 is both kinetically and thermodynamically unfavourable, whereas the pathways in the positions 1 and 3 are competitive. Pathway 1 requires the lowest activation energies, but E3 is significantly more stable than other two products. In accord with these findings are the experimental results which show that, at very low temperature (293 K) only E1 is formed at low yield, whereas the yields of E3 and E6 increase with the increasing temperature. Since the Kolbe-Schmitt reaction is experimentally performed at relatively high temperatures (around 500 K), the main product is thermodynamically most stable E6.

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Section: Rezultati I Diskusijaunclassified

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Carboxylation of sodium 2-naphthoxide. Reinvestigation of the mechanism by means of a hybrid meta density functional theory method

Djurovic

Marković

Markovic

2015

Hem Ind

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“…This path can be applied for activated, electron-rich phenols with at least two electron-donating OH groups. Although the KolbeSchmitt synthesis for a long time has been industrially applied to produce pharmaceuticals like Aspirin®, antimicrobials, or fine chemicals [3][4][5][6], especially the variant carried out in solution was regarded to have high potential for process intensification. Encouraged by the results of preliminary investigations at IMM [7][8][9], a research project had been carried out in the framework of the funding cluster Novel Process Windows of the Deutsche Bundesstiftung Umwelt (DBU) focusing on transferring the best lab-scale results to the pilot scale.…”

Section: Motivationmentioning

confidence: 99%

“…The concentrations of KHCO 3 and resorcinol in water were 2.5 mol L -1 and 0.83 mol L -1 , respectively. Both reactants were first dissolved in water separately.…”

Section: Chemical Protocolmentioning

confidence: 99%

Kolbe‐Schmitt Flow Synthesis in Aqueous Solution – From Lab Capillary Reactor to Pilot Plant

et al. 2013

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Significant process intensification was achieved for the continuously operated Kolbe-Schmitt synthesis of 2,4-dihydroxybenzoic acid (b-resorcylic acid) on laboratory scale by using different approaches opening novel process windows. The results of the optimal process variant, both from the economic and ecological view, were scaled up to the pilot scale. In a first step, the synthesis from resorcinol in aqueous potassium hydrogen carbonate solution was transferred from the capillary reactor to a tailor-made electrically heated microstructured reactor comprising 40 microchannels and enabling a 25-fold increase of the capacity. In a second step, a pilot plant comprising three of such reactors operated in parallel was built and successfully tested with the same reaction.

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Acid–Base and Solvation Properties of Metal PhenolatesThis chapter is dedicated to Prof. Rainer Beckert on the occasion of his 60 ^th birthday.

Bastos

Bartoloni

Gonçalves

2012

Patai's Chemistry of Functional Groups

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This chapter presents an overview of the acid‐base and solvation properties of metal phenolates. The effect of the metal counterion on the structure, physicochemical properties and chemical reactivity is discussed. Medium effects on the acid‐base equilibrium as well as on chemical reactivity and electronic properties of metal phenolates are summarized. Reference data, such as dissociation constants and partition coefficients, are compiled.

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Carboxylation of alkali metal phenoxide with carbon dioxide at terrestrial temperature

Cited by 24 publications

References 6 publications

Carboxylation of sodium 2-naphthoxide. Reinvestigation of the mechanism by means of a hybrid meta density functional theory method

Carboxylation of sodium 2-naphthoxide. Reinvestigation of the mechanism by means of a hybrid meta density functional theory method

Kolbe‐Schmitt Flow Synthesis in Aqueous Solution – From Lab Capillary Reactor to Pilot Plant

Acid–Base and Solvation Properties of Metal PhenolatesThis chapter is dedicated to Prof. Rainer Beckert on the occasion of his 60 ^th birthday.

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Carboxylation of alkali metal phenoxide with carbon dioxide at terrestrial temperature

Cited by 24 publications

References 6 publications

Carboxylation of sodium 2-naphthoxide. Reinvestigation of the mechanism by means of a hybrid meta density functional theory method

Carboxylation of sodium 2-naphthoxide. Reinvestigation of the mechanism by means of a hybrid meta density functional theory method

Kolbe‐Schmitt Flow Synthesis in Aqueous Solution – From Lab Capillary Reactor to Pilot Plant

Acid–Base and Solvation Properties of Metal PhenolatesThis chapter is dedicated to Prof. Rainer Beckert on the occasion of his 60 th birthday.

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Acid–Base and Solvation Properties of Metal PhenolatesThis chapter is dedicated to Prof. Rainer Beckert on the occasion of his 60 ^th birthday.