35836-73-8Relevant articles and documents
Highly active and recyclable metal oxide catalysts for the prins condensation of biorenewable feedstocks
Costa, Vinicius V.,Bayahia, Hossein,Kozhevnikova, Elena F.,Gusevskaya, Elena V.,Kozhevnikov, Ivan V.
, p. 2134 - 2139 (2014)
Metal oxides such as Nb2O5, Cr2O 3, and especially a ZnII-CrIII mixed oxide are demonstrated to be highly active and recyclable heterogeneous catalysts for Prins condensation, which provides a clean, high-yielding route for the synthesis of nopol through the condensation of biorenewable β-pinene with paraformaldehyde. Zn-Cr mixed oxide with an optimum Zn/Cr atomic ratio of 1:6 gave 100% nopol selectivity at 97% β-pinene conversion, with the catalyst easily recovered and recycled. The acid properties of Nb2O 5 and Zn-Cr mixed oxide were characterized by the diffuse reflectance IR Fourier transform spectroscopy of adsorbed pyridine and ammonia adsorption microcalorimetry. An appropriate combination of acid-base properties of Zn-Cr mixed oxide is believed to be responsible for its efficiency.
On the synergistic catalytic properties of bimetallic mesoporous materials containing aluminum and zirconium: The prins cyclisation of citronellal
Telalovic, Selvedin,Ramanathan, Anand,Ng, Jeck Fei,Maheswari, Rajamanickam,Kwakernaak, Cees,Soulimani, Fouad,Brouwer, Hans C.,Chuah, Gaik Khuan,Weckhuysen, Bert M.,Hanefeld, Ulf
, p. 2077 - 2088 (2011)
Bimetallic three-dimensional amorphous mesoporous materials, Al-Zr-TUD-1 materials, were synthesised by using a surfactant-free, one-pot procedure employing triethanolamine (TEA) as a complexing reagent. The amount of aluminium and zirconium was varied in order to study the effect of these metals on the Bronsted and Lewis acidity, as well as on the resulting catalytic activity of the material. The materials were characterised by various techniques, including elemental analysis, X-ray diffraction, high-resolution TEM, N2 physisorption, temperature-programmed desorption (TPD) of NH3, and 27Al MAS NMR, XPS and FT-IR spectroscopy using pyridine and CO as probe molecules. Al-Zr-TUD-1 materials are mesoporous with surface areas ranging from 700-900am2 g-1, an average pore size of around 4anm and a pore volume of around 0.70acm3 g -1. The synthesised Al-Zr-TUD-1 materials were tested as catalyst materials in the Lewis acid catalysed Meerwein-Ponndorf-Verley reduction of 4-tert-butylcyclohexanone, the intermolecular Prins synthesis of nopol and in the intramolecular Prins cyclisation of citronellal. Although Al-Zr-TUD-1 catalysts possess a lower amount of acid sites than their monometallic counterparts, according to TPD of NH3, these materials outperformed those of the monometallic Al-TUD-1 as well as Zr-TUD-1 in the Prins cyclisation of citronellal. This proves the existence of synergistic properties of Al-Zr-TUD-1. Due to the intramolecular nature of the Prins cyclisation of citronellal, the hydrophilic surface of the catalyst as well as the presence of both Bronsted and Lewis acid sites synergy could be obtained with bimetallic Al-Zr-TUD-1. Besides spectroscopic investigation of the active sites of the catalyst material a thorough testing of the catalyst in different types of reactions is crucial in identifying its specific active sites.
Synthesis of nopol over MCM-41 catalysts
Villa de P., Aida Luz,Alarcon, Edwin,De Correa, Consuelo Montes
, p. 2654 - 2655 (2002)
MCM-41 was found to be an active heterogeneous catalyst for the synthesis of nopol by the Prins condensation of β-pinene and paraformaldehyde, but Sn-MCM-41 in which Sn has been grafted on MCM-41 by chemical vapor deposition is far more active and combines high efficiency and recyclability.
Exploring the effect of acid modulators on MIL-101 (Cr) metal-organic framework catalysed olefin-aldehyde condensation: A sustainable approach for the selective synthesis of nopol
Kalidindi, Suresh Babu,Kanakikodi, Kempanna S.,Kulkarni, Bhavana B.,Maradur, Sanjeev P.,Rambhia, Dheer A.
supporting information, p. 726 - 738 (2022/01/22)
The development of efficient and sustainable strategies that evade the utilization of petroleum reserves is highly challenging yet inevitable today. In this regard, the conversion of pine tree-derived β-pinene to highly recognized nopol is particularly attractive owing to its widespread applications. Herein, we describe an approach that enables the selective synthesis of nopol based on the extraordinary activity of MIL-101(Cr). This remarkable activity of MIL-101(Cr) is attributed to its high specific surface area (SSA), accessible active sites in the mesopore architecture and unsaturated Cr3+ Lewis acid sites. We have established a good correlation between the superior catalytic performance and textural properties of the materials, which can be tuned by using different mineralizing agents. To realize the unprecedented catalytic activity, the influence of reaction parameters, solvent properties, and mineralizing agents has been investigated systematically. MIL-101(AA) (AA-acetic acid) showed the highest catalytic activity, which is superior to most of the reported materials for this transformation to date. The results of catalyst recycling and hot filtration experiments have emphasized that the catalyst is resistant towards leaching of active sites and retained its original catalytic activity beyond four recycles. An Eley-Rideal based model was used to study the reaction kinetics and establish a plausible reaction mechanism. The activation energy of the reaction was found to be 102 kJ mol-1 and the enthalpy of formaldehyde adsorption was -86.88 kJ mol-1. This approach opens up new avenues for the valorization of biomass-based molecules into useful chemicals.
Matteson Reaction under Flow Conditions: Iterative Homologations of Terpenes
Kuhwald, Conrad,Kirschning, Andreas
, p. 4300 - 4304 (2021/05/26)
The Matteson reaction is ideally suited for flow chemistry since it allows iterative homologation of boronate esters. The present study provides accurate data on reaction times of the individual steps of the Matteson reaction, which occurs in less than 10 s in total. The protocol allows terpenes to be (per-)homologated in a controlled manner to yield homo-, bishomo-, and trishomo-terpenols after oxidative workup. The new terpene alcohols are validated with respect to their olfactoric properties.
One-Pot Absolute Stereochemical Identification of Alcohols via Guanidinium Sulfate Crystallization
Brummel, Beau R.,Lee, Kinsey G.,McMillen, Colin D.,Kolis, Joseph W.,Whitehead, Daniel C.
, p. 9622 - 9627 (2019/12/02)
A novel technique for the absolute stereochemical determination of alcohols has been developed that uses crystallization of guanidinium salts of organosulfates. The simple one-pot, two-step process leverages facile formation of guandinium organosulfate single crystals for the straightforward determination of the absolute stereochemistry of enantiopure alcohols by means of X-ray crystallography. The strong hydrogen bonding network drives the stability of the crystal lattice and allows for a diverse range of organic alcohol substrates to be analyzed.
Nanosized sulfated zinc ferrite as catalyst for the synthesis of nopol and other fine chemicals
Jadhav, Sumit V.,Jinka, Krishna Mohan,Bajaj, Hari C.
, p. 98 - 105 (2013/01/15)
A nanosized highly ordered mesoporous zinc ferrite (ZnFe2O 4; ZF) was synthesized via co-precipitation method, further sulfated with ammonium sulfate solution to obtain sulfated ZF (SZF) and have been used for the synthesis of nopol by Prins condensation of β-pinene and paraformaldehyde. The NH3-TPD and pyridine sorption DRIFT-IR studies revealed the significant enhancement in Lewis acidic sites of the zinc ferrite on sulfatation. The influence of various reaction parameters such as reaction temperature, effect of substrate stoichiometry and catalyst loading has been investigated. It gave 70% conversion of β-pinene with 88% selectivity to nopol. The spent catalyst was regenerated and reused successfully up to four cycles with slight loss in catalytic activity. The nanosized SZF catalyst was found to be highly active towards several other commercially important acid catalyzed reactions such as isomerization, acetalization and aldol condensation.
Synthesis of nopol via Prins condensation of β-pinene and paraformaldehyde catalyzed by sulfated zirconia
Jadhav, Sumit V.,Jinka, Krishna Mohan,Bajaj, Hari C.
scheme or table, p. 158 - 165 (2011/12/21)
The present work describes the novel application of sulfated zirconia (SZ) solid acid catalysts for the synthesis of nopol via Prins condensation of β-pinene and paraformaldehyde. SZ catalysts with different percentages of sulfur loadings have been synthesized and characterized using various physico-chemical techniques like PXRD, FT-IR, surface area analysis and NH 3-TPD studies. The influences of various reaction parameters such as sulfur loading, reaction temperature, molar ratio of reactants, reaction time, solvent effect and reusability of the catalyst have been investigated. SZ catalyst synthesized by impregnation of 2N sulfuric acid solution over Zr(OH)4 was found to be a highly selective catalyst for β-pinene conversion (>99%) with ～99% selectivity to nopol. The catalyst could be reused up to five cycles with minor loss in catalytic activity for β-pinene conversion, while the nopol selectivity remains unaffected.
Efficient tetrahydropyranylation of alcohols and detetrahydropyranylation reactions in the presence of catalytic amount of trichloroisocyanuric acid (TCCA) as a safe, cheap industrial chemical
Firouzabadi, Habib,Iranpoor, Nasser,Hazarkhani, Hassan
, p. 3623 - 3630 (2007/10/03)
Preparation and cleavage of THP ethers of different hydroxy functional groups are easily and efficiently performed in the presence of trichloroisocyanuric acid (TCCA) in the absence of solvent with high yields.
The prenyl group: A versatile hydroxy protecting group, removable chemoselectively under mild conditions
Vatèle, Jean-Michel
, p. 5689 - 5698 (2007/10/03)
Iodine in dichloromethane (in the presence of 3? molecular sieves for acid-sensitive substrates) and 2,3-dichloro-5,6-dicyanoquinone (DDQ) in dichloromethane-water (9:1) are mild and efficient methods to cleave prenyl ethers. These reaction conditions are compatible with the presence of other protecting groups such as acetals, acetates, allyl, benzyl and TBDPS groups. Exposure of aryl prenyl ethers to iodine led to the formation of 3-iodo-2,2-dimethylchroman derivatives in acceptable yields via a tandem Friedel-Crafts/iodocyclization reactions. Facile one-step transformation of two iodinated dimethylchroman derivatives allowed the synthesis of natural flavanoids among them: zanthoxylol, an anti-sickling agent.
