Isomerization of eugenol to isoeugenol

Červený, Libor; Krejcikova, A.; Marhoul, A.; R∪žička, Vlastimil

doi:10.1007/bf02128108

Cited by 33 publications

(20 citation statements)

References 6 publications

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“…There are several reports of the isomerization of eugenol catalyzed by alkalis in alcoholic solutions [28], by solid bases [29][30][31], and by metal complexes [32]. Catalysis by bases is used industrially to catalyze the conversion of eugenol to isoeugenol [29].…”

Section: Discussionmentioning

confidence: 99%

Upgrading of Lignin-Derived Compounds: Reactions of Eugenol Catalyzed by HY Zeolite and by Pt/γ-Al2O3

et al. 2011

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The conversion of eugenol (4-allyl-2-methoxyphenol), a compound derived from the lignin in woody biomass, was catalyzed by HY zeolite at 573 K and atmospheric pressure. The main products were isoeugenol and guaiacol, formed by isomerization and by deallylation, respectively. Substituted guaiacols with saturated sidechains (4-methylguaiacol, 4-ethylguaiacol, and 4-propylguaiacol) were also formed, by hydrogen transfer and alkylation reactions. The pseudo-first-order rate constant for the overall disappearance of eugenol was found to be 12.4 L (g of catalyst)/h. When the catalyst was Pt/c-Al 2 O 3 used in the presence of H 2 , significant hydrogenation of the propenyl side-chain took place, accompanied by isomerization, and hydrodeoxygenation. Under similar operating conditions, the reaction catalyzed by Pt/c-Al 2 O 3 in the presence of H 2 gave a higher eugenol conversion (X = 0.70) than the reaction catalyzed by HY zeolite (X = 0.11), primarily because of the dominant hydrogenation observed with the former catalyst. In the absence of H 2 as a co-reactant, the acidic c-Al 2 O 3 support in Pt/c-Al 2 O 3 evidently catalyzed all the classes of reactions catalyzed by HY zeolite.

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Section: Discussionmentioning

confidence: 99%

Upgrading of Lignin-Derived Compounds: Reactions of Eugenol Catalyzed by HY Zeolite and by Pt/γ-Al2O3

et al. 2011

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“…Alkaline alcoholic solution or anhydrous RhCl 3 was also employed [10] as well as KF on neutral alumina [11][12][13] or hydrotalcites [6,14].…”

Section: Introductionmentioning

confidence: 99%

Isomerization of Eugenol Under Ultrasound Activation Catalyzed by Alkali Modified Mesoporous NbMCM-41

et al. 2009

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The present paper discloses a new alternative method for the isomerization of eugenol to isoeugenol where mesoporous materials containing niobium are used as solid base catalysts, affording good yields of isomerized product and being environmentally friendly. Nb-containing MCM-41 mesoporous materials were modified with alkaline cations (Li, Na, K, Rb and Cs) and characterized by BET, FTIR, XRD, and UV-vis techniques. The prepared materials were tested in the isomerization of eugenol to isoeugenol by sonochemical and thermally-activated reactions. Li, Na, K, Rb, and Cs/NbMCM-41 catalysts are active catalyst for the preparation of isoeugenol, and selective to the trans-isomer. Rb/NbMCM-41 sample is the optimum catalysts for the reaction. This result is in accordance with the calculated basicity observed during the Knoevenagel probe reaction of basicity. Conversions around 90% are obtained when using Rb-NbMCM-41 catalysts, with 90% selectivity to trans-isoeugenol, under ultrasound activation. In contrast, conversion around 72% with 90% selectivity is attained under classical thermal activation. The catalysts were reused four times without a substantial decrease of activity.

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“…Traditionally this reaction is catalyzed by KOH in alcoholic solutions (most often in higher alcohols) at high temperatures. Alternatively, complexes of group VIII elements are used to catalyze the reaction [106]. Recently microwave assisted isomerization of chemicals with perfumery interest were done using both conventional bases and solid base catalyst and observed an enhancement in the activity under microwave irradiation compared to conventional heating, attributed for local superheating [107].…”

Section: Isomerization Of Safrole Over Mgal Hydrotalcites and Their Mmentioning

confidence: 99%

Catalytic applications of hydrotalcite-like materials and their derived forms

Srinivasan

2006

Catal Surv Asia

108

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Hydrotalcite-like (HT-like) materials have been studied extensively in the last three decades. Although these materials initially perceived as potential anion exchangers, unrelenting efforts have also been attempted to use them as catalytic materials or as catalytic supports. There are varied ways by which one can use them for catalysis viz.; 1. Use them in as-synthesized form 2. Use them after calcining where the structural integrity of layered lattice is lost 3. Use the interlayer as functional spaces with moieties of catalytic interest 4. Use them after destruction or delamination and restructuring and 5. Use them as support or matrix. In this review, we are reporting the catalytic applications of HT-like materials and their derived forms carried out in our research group for the last 15 years in these various ways, covering reactions such as nitrous oxide decomposition, selective oxidation of organic compounds of industrial relevance and base-catalyzed isomerization of chemicals of perfumery interest. Although this review primarily focuses on our work, wherever applicable, related or relevant works from other groups are also presented to bestow comprehensiveness.

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Isomerization of eugenol to isoeugenol

Cited by 33 publications

References 6 publications

Upgrading of Lignin-Derived Compounds: Reactions of Eugenol Catalyzed by HY Zeolite and by Pt/γ-Al2O3

Upgrading of Lignin-Derived Compounds: Reactions of Eugenol Catalyzed by HY Zeolite and by Pt/γ-Al2O3

Isomerization of Eugenol Under Ultrasound Activation Catalyzed by Alkali Modified Mesoporous NbMCM-41

Catalytic applications of hydrotalcite-like materials and their derived forms

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