Intramolecular cyclization of (+)-citronellal using supported 12-tungstophosphoric acid on MCM-41

Braga, Patricia Regina Sobral; Costa, Andréia Alves; Freitas, Elon Ferreira de; Rocha, Rafael O.; Macedo, Julio L. de; Araújo, Antônio S.; Dias, José A.; Dias, Sílvia C.L.

doi:10.1016/j.molcata.2012.03.002

Cited by 37 publications

(10 citation statements)

References 38 publications

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“…The nature of the support and the conditions used in the catalyst synthesis are important parameters for improving the stability of H 3 PW supported materials. [9][10][11][12]42 The commercial silica-alumina showed 489 m 2 g -1 (S BET ) and 0.69 cm 3 g -1 of pore volume (P v . Table 1 shows the normalized (S N ) and decreased (S D ) calculated specific surface values for all the samples, indicating that an approximated constant decrease of surface area was reached around 30% of impregnation.…”

Section: Resultsmentioning

confidence: 99%

Acidity and Characterization of 12-Tungstophosphoric Acid Supported on Silica-Alumina

Mattos¹,

Carvalho²,

Freitas³

et al. 2016

Journal of the Brazilian Chemical Society

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This work deals with preparation and characterization of H 3 PW 12 O 40 (H 3 PW) supported on silica-alumina. Impregnation of H 3 PW (15, 20, 30 and 40 wt.%) on commercial silica-alumina support in acidic aqueous solution is effective for preparing this catalyst keeping its Keggin structure, according to different methods of characterization. The catalysts were tested in a model reaction of acetic acid with ethanol and 30 wt.% H 3 PW/SiO 2 -Al 2 O 3 had the highest activity under the conditions: catalyst calcination at 300 °C, temperature of 100 °C, acetic acid:ethanol molar ratio of 2:1 and catalyst:acetic acid mass ratio of 10 wt.%. The reaction yield was 79 and 100% selectivity for ethyl acetate over three reutilizations, for reaction time of 2 h. The calculated total acid site distribution was 0.299 mmol g -1 (97% of the theoretical probed by pyridine), and most of these (0.236 mmol g -1 ) were Brønsted weak-medium strength (pyridine desorption between 300 and 500 °C).

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Section: Resultsmentioning

confidence: 99%

Acidity and Characterization of 12-Tungstophosphoric Acid Supported on Silica-Alumina

Mattos¹,

Carvalho²,

Freitas³

et al. 2016

Journal of the Brazilian Chemical Society

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“…The acid-catalysed intramolecular Prins cyclization of citronellal is an interesting reaction providing isopulegol as an important fragrant compound and intermediate for the synthesis of another fragrant compound, menthol (Scheme 4). Both Lewis acids (e. g. ZnCl 2 or ZrO 2 ) [53,54] and Brønsted acids (e. g. heteropolyacids) [55] can be used as the catalysts for this reaction. Figure 8 and Table 6 show that P(1,4-DEB)-SO 3 H and P(1,3-DEB)-SO 3 H were highly active not only in esterification and Prins cyclization of various aldehydes with isoprenol but also in the intramolecular cyclization of citronellal.…”

Section: Catalytic Activitymentioning

confidence: 99%

Sulfonated Hyper‐cross‐linked Porous Polyacetylene Networks as Versatile Heterogeneous Acid Catalysts

et al. 2019

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Two highly sulfonated micro/mesoporous polymers, P(1,3‐DEB)‐SO3H and P(1,4‐DEB)‐SO3H, with permanent porosity, the specific surface area about 550 m2 ⋅ g−1 and the content of SO3H groups of 2.7 mmol ⋅ g−1 were prepared as new acid Porous Polymer Catalysts, PPCs. The PPCs were achieved by easy sulfonation of parent hyper‐cross‐linked micro/mesoporous polyacetylene‐type networks resulting from a chain‐growth homopolymerization of 1,3‐ and 1,4‐diethynylbenzenes. New PPCs are reported as highly active and reusable heterogeneous catalysts of esterification of fatty acids with methanol and ethanol, Prins cyclization of aldehydes with isoprenol and intramolecular Prins cyclization of citronellal to isopulegol. The catalytic activity of the micro/mesoporous PPCs (TON values up to 522 mol ⋅ mol−1) was higher than that of commercial polymer‐based heterogeneous catalyst Amberlyst 15 possessing gel texture without permanent pores and that of p‐toluenesulfonic acid applied as a homogeneous catalyst.

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“…Menthol itself theoretically can be produced by hydrogenation of isopulegol in general or two steps reaction. Although the specific surface area of Ni/Zr-MMT and Ni/SZr-MMT are lower than raw MMT but the presence of sulfate ions and also nickel content activate both cyclization, isomerization and hydrogenation mechanism [19]. The selectivity value in producing menthol of Ni/Zr-MMT and Ni/SZr-MMT are higher compared to S-Zr/MMT suggests that nickel play important role in the hydrogenation mechanism as hydrogen catcher during surface mechanism.…”

Section: Catalyst Conversion(%) Selectivity To Isopulegolmentioning

confidence: 93%

Ni Dispersed on Sulfated Zirconia Pillared Montmorillonite as Bifunctional Catalyst in Eco-Friendly Citronellal Conversion

Fatimah

Rubiyanto

Huda

et al. 2015

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Preparation of nickel dispersed on sulfated zirconia pillared montmorillonite(Ni/S-Zr/MMT) and its application as catalyst in citronellal conversion was investigated. Preparation of material was conducted by three main steps; zirconia pillarization, sulfation and nickel dispersion. The synthesized material was characterized with FTIR spectroscopy, elemental analysis, x-ray diffraction and gas sorption analyzer and catalytic activity was tested for microwave assisted citronellal conversion via catalytic hydrogen transfer mechanism. The results showed that the obtained material gave high total conversion and demonstrated cyclization, isomerization and hydrogenation mechanism in one pot reaction. The presence of sulfate and nickel in the catalyst play important role within the mechanism.

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Intramolecular cyclization of (+)-citronellal using supported 12-tungstophosphoric acid on MCM-41

Cited by 37 publications

References 38 publications

Acidity and Characterization of 12-Tungstophosphoric Acid Supported on Silica-Alumina

Acidity and Characterization of 12-Tungstophosphoric Acid Supported on Silica-Alumina

Sulfonated Hyper‐cross‐linked Porous Polyacetylene Networks as Versatile Heterogeneous Acid Catalysts

Ni Dispersed on Sulfated Zirconia Pillared Montmorillonite as Bifunctional Catalyst in Eco-Friendly Citronellal Conversion

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