586-63-0Relevant academic research and scientific papers
TRANSFORMATIONS OF p-MENTHADIENES UNDER THE ACTION OF POTASSIUM tert-BUTANOLATE IN DIMETHYL SULFOXIDE
Buinova, E. F.,Urbanovich, T. R.,Udarov, B. G.,Izotova, L. V.
, p. 555 - 559 (1982)
The products of the transformation of α- and γ-terpinenes, terpinolene, (+)-trans-isolimonene, and (+)-limonene under the action of potassium tert-butanolate in dimethyl sulfoxide contained - in addition to the α- and γ-terpinenes, isoterpinolene, p-mentha-3,8-diene and p-cymene found previously - terpinolene, α- and β-phellandrenes, p-mentha-2,4-diene (in total amount of 1-3percent), and polymers.Under these conditions, limonene is racemized.The primary products of the isomerization reaction have been identified.A supplementary scheme for the isomerization transformations of p-menthadienes is presented.
Transition metal triflate catalyzed conversion of alcohols, ethers and esters to olefins
Keskiv?li,Parviainen,Lagerblom,Repo
, p. 15111 - 15118 (2018/05/04)
Herein, we report an efficient transition metal triflate catalyzed approach to convert biomass-based compounds, such as monoterpene alcohols, sugar alcohols, octyl acetate and tea tree oil, to their corresponding olefins in high yields. The reaction proceeds through C-O bond cleavage under solvent-free conditions, where the catalytic activity is determined by the oxophilicity and the Lewis acidity of the metal catalyst. In addition, we demonstrate how the oxygen containing functionality affects the formation of the olefins. Furthermore, the robustness of the used metal triflate catalysts, Fe(OTf)3 and Hf(OTf)4, is highlighted by their ability to convert an over 2400-fold excess of 2-octanol to octenes in high isolated yields.
Terpene Cyclizations inside a Supramolecular Catalyst: Leaving-Group-Controlled Product Selectivity and Mechanistic Studies
Zhang, Qi,Catti, Lorenzo,Pleiss, Jürgen,Tiefenbacher, Konrad
, 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.
Hybrid catalysts based on platinum and palladium nanoparticles for the hydrogenation of terpenes under slurry conditions
Karakhanov,Boronoev,Subbotina,Zolotukhina,Maximov,Filippova, T. Yu.
, p. 1114 - 1122 (2017/02/15)
Catalysts based on platinum and palladium nanoparticles immobilized in mesoporous phenolformaldehyde polymers modified with sulfo groups have been used for the hydrogenation of a number of terpenes, such as (S)-(–)-limonene, α-terpinene, γ-terpinene, and terpinolene. It has been found that Pd-containing catalysts exhibit higher activity in the exhaustive hydrogenation of terpenes, whereas Pt-containing catalysts have high selectivity for p-menthene.
Structural studies of high dispersion H3PW12O 40/SiO2 solid acid catalysts
Newman, Andrew D.,Brown, D. Robert,Siril, Prem,Lee, Adam F.,Wilson, Karen
, p. 2893 - 2902 (2008/02/08)
Highly dispersed H3PW12O40/SiO2 catalysts with loadings between 3.6 and 62.5 wt% have been synthesised and characterised. The formation of a chemically distinct interfacial HPW species is identified by XPS, attributed to pertubation of W atoms within the Keggin cage in direct contact with the SiO2 surface. EXAFS confirms the Keggin unit remains intact for all loadings, while NH3 adsorption calorimetery reveals the acid strength >0.14 monolayers of HPW is loading invariant with initial ΔHads = ～-164 kJ mol-1. Lower loading catalysts exhibit weaker acidity which is attributed to an inability of highly dispersed clusters to form crystalline water. For reactions involving non-polar hydrocarbons the interfacial species where the accessible tungstate is highest confer the greatest reactivity, while polar chemistry is favoured by higher loadings which can take advantage of the H3PW 12O40 pseudo-liquid phase available within supported multilayers. the Owner Societies 2006.
Reduction of alkyl and vinyl sulfonates using the CuCl2· 2H2O-Li-DTBB(cat.) system
Radivoy, Gabriel,Alonso, Francisco,Moglie, Yanina,Vitale, Cristian,Yus, Miguel
, p. 3859 - 3864 (2007/10/03)
The reduction of a series of alkyl mesylates, dimesylates and triflates to the corresponding hydrocarbons was efficiently performed using a reducing system composed of CuCl2·2H2O, an excess of lithium sand and a catalytic amount (5 mol%) of 4,4′-di-tert-butylbiphenyl (DTBB), in tetrahydrofuran at room temperature. The process was also applied to enol and dienol triflates affording alkenes and dienes, respectively. The use of the deuterated copper salt CuCl2·2D2O allowed the simple preparation of the corresponding deuterated products.
Thermal transformation of monoterpenes within thionin-supported zeolite Na-Y. Acid-catalyzed or electron transfer-induced?
Stratakis, Manolis,Stavroulakis, Manolis,Sofikiti, Nikoletta
, p. 16 - 20 (2007/10/03)
Several monoterpenes (monocyclic, bicyclic or acyclic) isomerize and finally transform to p-cymene in the dark upon loading within thionin-supported zeolite Na-Y. The same reactions occur in Na-Y dried under the same conditions as thionin/Na-Y. It is postulated that the thermal treatment of Na-Y generates 'electron holes' (probably acidic sites). The transformation of monoterpenes occurs more likely via an electron transfer-induced reaction subordinated to the occurrence of the acidic sites. The radical cation of the more thermodynamically stable monoterpene, α-terpinene, eventually dehydrogenates to p-cymene. For comparison, the same reactions were performed within methyl viologen-supported Na-Y. Copyright
Dimethyl-(4-methyl-1-cyclohexenyl)methyl and 2-(1-methylethylidene)-5- methylcyclohexyl ethers from pulegone
Spencer
, p. 1603 - 1615 (2007/10/02)
NaBH4 reduction of pulegone (1) in short chain alcohols followed by acidification of the reaction mixture gives dimethyl-(4-methyl-1- cyclohexenyl) ethers. Acid catalyzed transetherification of these ethers in longer chain alcohols yields mixtures of the title compounds.
CARBOCATIONIC TRANSFORMATIONS OF p-MENTHADIENES
Bardyshev, I.I.,Popova, L. A.
, p. 1026 - 1034 (2007/10/02)
The dynamics of the mutual carbocationic transformations were studied for the first time for the most important monoterpenoid hydrocarbons of the p-menthane series - β-limonene, limonene, terpinolene, isolimonene, isoterpinolene, α-terpinene, γ-terpinene, α-phellandrene, and β-phellandrene.The order of formation of the primary, secondary, tertiary, and other products of these transformations (with time) was established.On the basis of the obtained results a general scheme was formulated for the carbocationic transformations of p-menthadienes under the influence of acids.The fundamental possibility of using these reactions for the partial synthesis of individual rare hydrocarbons of the p-menthane series was demonstrated.
Thermodynamics of the Isomerisation of the p-Menthadienes and the Additivity of the Properties of Cyclic Hydrocarbons
Kabo, G. Ya.,Roganov, G. N.,Filippenko, Z. A.
, p. 1521 - 1522 (2007/10/02)
We have studied the equilibria and obtained the thermodynamic parameters for the isomerisation of nine p-menthadienes in the range 225-350 deg C.An approach has been proposed and shown to be effective for the additive calculation of the properties of aliphatic hydrocarbons: this is based on the introduction of additional effective characteristics for an atom which take into account its participation in the ring system of the molecule.
