80-26-2Relevant articles and documents
Pd(OAc)2/M(NO3)n (M = Cu(II), Fe(III); n = 2, 3): Kinetic investigations of an alternative Wacker system for the oxidation of natural olefins
da Silva, Márcio J.,Teixeira, Róbson Ricardo,Carari, Danielli Marcolan
, p. 3254 - 3261 (2009)
Pd-catalyzed oxidative coupling of camphene by dioxygen afforded mainly a diene, which subsequently underwent oxidation to a ring-expanded β,γ-unsaturated ketone with LiNO3 as reoxidant. However, the instability of LiNO3 results to t
Synthesis of Terpineol from Alpha-Pinene Catalyzed by α-Hydroxy Acids
Hu, Yi-Ming,Huang, Xiao-Rui,Meng, Zhong-Lei,Qin, Rong-Xiu,Wen, Ru-Si,Zhou, Yong-Hong
, (2022/02/17)
We report the use of five alpha-hydroxy acids (citric, tartaric, mandelic, lactic and glycolic acids) as catalysts in the synthesis of terpineol from alpha-pinene. The study found that the hydration rate of pinene was slow when only catalyzed by alpha-hydroxyl acids. Ternary composite catalysts, composed of AHAs, phosphoric acid, and acetic acid, had a good catalytic performance. The reaction step was hydrolysis of the intermediate terpinyl acetate, which yielded terpineol. The optimal reaction conditions were as follows: alpha-pinene, acetic acid, water, citric acid, and phosphoric acid, at a mass ratio of 1:2.5:1:(0.1–0.05):0.05, a reaction temperature of 70? C, and a reaction time of 12–15 h. The conversion of alpha-pinene was 96%, the content of alpha-terpineol was 46.9%, and the selectivity of alpha-terpineol was 48.1%. In addition, the catalytic performance of monolayer graphene oxide and its composite catalyst with citric acid was studied, with acetic acid used as an additive.
Preparation of α-terpineol and perillyl alcohol using zeolites beta
?erveny, Libor,Vysko?ilová, Eli?ka,Zítová, Kate?ina
, p. 4297 - 4310 (2021/07/26)
The preparation of α-terpineol by direct hydration of limonene catalyzed by zeolites beta was studied. The same catalyst was used to prepare perillyl alcohol by isomerization of β-pinene oxide in the presence of water. The aim was to optimize the reaction conditions to achieve high conversions of starting material and high selectivity to the desired products. In the case of limonene, it was found that the highest selectivity to α-terpineol was 88% with conversion of 36% under the conditions: 50?wt% of catalyst beta 25, 10% aqueous acetic acid (10?mL) (volume ratio limonene:H2O = 1:4.5), temperature 50?°C, after 24?h. In the case of β-pinene oxide, it was found that the highest selectivity to perillyl alcohol, which was 36% at total conversion, was obtained in the reaction under the following conditions: dimethyl?sulfoxide as solvent (volume ratio β-pinene oxide:DMSO = 1:5), catalyst beta 25 without calcination (15?wt%), demineralized water (molar ratio β-pinene oxide:H2O = 1:8), temperature 70?°C, 3?h. The present study shows that the studied reactions are suitable for the selective preparation of chosen compounds.
Heterogeneous zeolite-based catalyst for esterification of α-pinene to α-terpinyl acetate
Wijayati, Nanik,Kusumastuti, Ella,Alighiri, Dante,Rohmawati, Baiti,Lusiana, Retno Ariadi
, p. 399 - 403 (2019/06/05)
The purpose of this study is to determine the most effective type of heterogeneous catalyst such as natural zeolite (ZA), Zr-natural zeolite (Zr/ZA) and zeolite Y (H/ZY) in esterification of α-pinene. α-terpinyl acetate was successfully synthesized from α-pinene and acetic anhydride by their heterogeneous catalysts. The esterification reaction was carried out with reaction time, temperature and zeolite catalysts. The most effective catalysts used in the synthesis of α-terpinyl acetate is catalyst H/ZY with the yield is 52.83% at 40oC for the time 4 h with a selectivity of 61.38%. The results showed that the effective separation of catalyst could contribute to developing a new strategy for the synthesis of α-terpinyl acetate.
Discovery of a novel series of α-terpineol derivatives as promising anti-asthmatic agents: Their design, synthesis, and biological evaluation
Zhu, Wanping,Liu, Xia,Wang, Yuji,Tong, Yeling,Hu, Yongzhou
, p. 419 - 425 (2017/12/07)
A series of novel α-terpineol derivatives were designed and synthesized through structural derivatization of the tertiary hydroxyl moiety or reduction of the double bond. Of the resulting compounds, eight compounds enhanced relaxation of airway smooth muscle (ASM) compared to the α-terpineol precursor, and four compounds (4a, 4d, 4e, and 4i)were superior or comparable to aminophylline at a concentration of 0.75 mmol/L. Assays for 3′-5′-Cyclic adenosine monophpsphate (cAMP) activation revealed that some representative α-terpineol derivatives in this series were capable of upregulating the level of cAMP in ASM cells. Further in vivo investigation using the asthmatic rat model, illustrated that treatment with the compounds 4a and 4e resulted in significantly lowered lung resistance (RL) and enhanced dynamic lung compliance (Cldyn), two important parameters for lung fuction. Moreover, treatment with 4e downregulated the levels of both IL-4 and IL-17. Due to its several favorable physiological functions, including ASM relaxation activity, cAMP activation capability, and in vivo anti-asthmatic efficacy, 4e is a promising remedy for bronchial asthma, meriting extensive development.
M -C2B10H11HgCl/AgOTf-Catalyzed Reaction for Reductive Deoxygenation
Yamasaki, Naoto,Kanno, Marina,Sakamoto, Kyohei,Kasai, Yusuke,Imagawa, Hiroshi,Yamamoto, Hirofumi
, p. 169 - 175 (2018/03/26)
A m -C2B10H11HgCl/AgOTf-catalyzed reaction of allyl silyl ethers with N -Boc- N ′-tosylhydrazine has been developed. Under mild conditions, the resulting allyl hydrazine products were transformed into naked alkenes in good yield. Furthermore, the used m -C2B10H11HgCl could be recovered quantitatively.
Terpene Cyclizations inside a Supramolecular Catalyst: Leaving-Group-Controlled Product Selectivity and Mechanistic Studies
Zhang, Qi,Catti, Lorenzo,Pleiss, Jürgen,Tiefenbacher, Konrad
supporting information, p. 11482 - 11492 (2017/08/30)
The tail-to-head terpene cyclization is arguably one of the most complex reactions found in nature. The hydrogen-bond-based resorcinarene capsule represents the first man-made enzyme-like catalyst that is capable of catalyzing this reaction. Based on noncovalent interactions between the capsule and the substrate, the product selectivity can be tuned by using different leaving groups. A detailed mechanistic investigation was performed to elucidate the reaction mechanism. For the cyclization of geranyl acetate, it was found that the cleavage of the leaving group is the rate-determining step. Furthermore, the studies revealed that trace amounts of acid are required as cocatalyst. A series of control experiments demonstrate that a synergistic interplay between the supramolecular capsule and the acid traces is required for catalytic activity.
Unravelling transition metal-catalyzed terpenic alcohol esterification: A straightforward process for the synthesis of fragrances
Da Silva,Ayala
, p. 3197 - 3207 (2016/05/24)
Iron nitrate is a simple and commercially available Lewis acid and is demonstrated to be able to catalyze β-citronellol esterification with acetic acid, achieving high conversion and ester selectivity (ca. 80 and 70%, respectively), within shorter reaction times than those reported in the literature. To the best of our knowledge, this is the first report of a terpenic alcohol esterification reaction catalyzed by Fe(NO3)3. This process is an attractive alternative to the slow and expensive enzymatic processes commonly used in terpenic alcohol esterification. Moreover, it avoids the undesirable steps of neutralizing the products, which are always required in mineral acid-catalyzed reactions. We have performed a study of the activity of different metal Lewis acid catalysts, and found that their efficiency is directly linked to the ability of the metal cation to generate H+ ions from acetic acid ionization. The measurement of pH as well as the conversions achieved in the reactions allowed us to obtain the following trend: Fe(NO3)3 > Al(NO3)3 > Cu(NO3)2 > Ni(NO3)2 > Zn(NO3)2 > Mn(NO3)2 > Co(NO3)2 > LiNO3. The first three are recognized as stronger Lewis acids and they generate more acidic solutions. When we carried out reactions with different iron salts, it was possible to conclude that the type of anion affects the solubility of the catalyst, as well as the conversion and selectivity of the process. Fe2(SO4)3 and FeSO4 were insoluble and less active. Conversely, though they were equally soluble, Fe(NO3)3 was more selective for the formation of β-citronellyl acetate than FeCl3. We assessed the effects of the main reaction variables such as reactant stoichiometry, temperature, and catalyst concentration. In addition to citronellol, we investigated the efficiency of the iron(iii) catalyst in the solvent free esterification of several terpenic alcohols (geraniol, nerol, linalool, α-terpineol) as well as other carboxylic acids.
Α- [...] enol derivative and its preparation method and application
-
Paragraph 0035; 0036, (2017/05/03)
The invention discloses alpha-terpineol derivatives, the structure of which is shown as the formula (II), wherein R or H is C1-C5 alkyl. The alpha-terpineol derivatives can be obtained by performing esterification reaction on a raw material alpha-terpineol with acid or acid anhydride at the temperature of 18-30DEG C under the action of 4-methylbenzenesulfonyl chloride. The invention further discloses applications of the alpha-terpineol derivatives in preparing antiasthmatic drugs, carboxylic ester prodrug formed by introducing carboxylic ester on the hydroxyl of the alpha-terpineol derivatives can be slowly hydrolyzed in a human body to release parent drug and further prolong the curative effect and the acting time, in addition the bioavailability can be improved, and the antiasthma activity can be further enhanced.
Proton-gradient-transfer acid complexes and their catalytic performance for the synthesis of geranyl acetate
Chen, Yongle,Ding, Shiya,Zheng, Wentao,Zhang, Yiyang,Wu, Youting,Hu, Xingbang
, p. 2114 - 2121 (2017/01/16)
Special proton-gradient-transfer acid complexes (PGTACs) in which the bonded protons are not equivalent and have gradients in transfer ability, acidity, and reactivity were reported. The acidity gradient of the protons gave the PGTACs excellent catalytic activity and selectivity in the esterification of terpenols. These PGTACs are “reaction-induced self-separation catalysts” and can be easily reused. The kinetics with PGTACs as catalyst in the esterification of geraniol were also studied for use in engineering design.
