28098-68-2

Upstream product

• 200723-09-7 (4R,8Ξ)-p-menth-1-ene-8,9-diol 
• 5989-27-5 D-limonene 
• 107090-89-1 (4R,8R)-8-hydroxy-p-menth-1-en-9-yl p-toluenesulfonate 
• 4648-54-8 trimethylsilylazide 
• 184488-93-5 (R)-8,9-limonene oxide 
• 50429-63-5 (1S,2S,4R)-1,2-dibromo-p-menth-8-ene 

Downstream Products

• 96-08-2 (1S,4R,6R)-1-methyl-4-((R)-2-methyloxiran-2-yl)-7-oxa-bicyclo[4.1.0]heptane 
• 96-08-2 (1R,4R,6S)-1-methyl-4-((R)-2-methyloxiran-2-yl)-7-oxa-bicyclo[4.1.0]heptane 
• 96-08-2 (1S,4R,6R)-1-methyl-4-((S)-2-methyloxiran-2-yl)-7-oxa-bicyclo[4.1.0]heptane 
• 96-08-2 (1R,4R,6S)-1-methyl-4-(S)-2-methyloxiran-2-yl-7-oxa-bicyclo[4.1.0]heptane 

Relevant academic research and scientific papers

Selective Catalytic Synthesis of 1,2- and 8,9-Cyclic Limonene Carbonates as Versatile Building Blocks for Novel Hydroxyurethanes

The selective catalytic synthesis of limonene-derived monofunctional cyclic carbonates and their subsequent functionalisation via thiol–ene addition and amine ring-opening is reported. A phosphotungstate polyoxometalate catalyst used for limonene epoxidation in the 1,2-position is shown to also be active in cyclic carbonate synthesis, allowing a two-step, one-pot synthesis without intermittent epoxide isolation. When used in conjunction with a classical halide catalyst, the polyoxometalate increased the rate of carbonation in a synergistic double-activation of both substrates. The cis isomer is shown to be responsible for incomplete conversion and by-product formation in commercial mixtures of 1,2-limomene oxide. Carbonation of 8,9-limonene epoxide furnished the 8,9-limonene carbonate for the first time. Both cyclic carbonates underwent thiol–ene addition reactions to yield linked di-monocarbonates, which can be used in linear non-isocyanate polyurethanes synthesis, as shown by their facile ring-opening with N-hexylamine. Thus, the selective catalytic route to monofunctional limonene carbonates gives straightforward access to monomers for novel bio-based polymers.

Limonene epoxidation with H2O2 promoted by Al2O3: Kinetic study, experimental design

A highly efficient oxidation of limonene with hydrogen peroxide promoted by cheap aluminum oxide has been studied. The reaction is a rare example of the epoxidation promoted by a derivative of non-transition metal having a single stable non-zero oxidation state (SSOS metal), and it affords epoxides which are highly valuable products (fragrances, food additives and monomers). Typically, ethyl acetate at 80 °C was used as a solvent. The experimental data have been described by the proposed kinetic scheme. The optimization of the limonene epoxidation using a 23 experimental design has been carried out.

Design, preparation, and study of catalytic gated baskets

We report a diastereoselective synthetic method to obtain a family of catalytic molecular baskets containing a spacious cavity (～570 A3). These supramolecular catalysts were envisioned, via the process of gating, to control the access of substrates to the embedded catalytic center and thereby modulate the outcome of chemical reactions. In particular, gated basket 1 comprises a porphyrin floor fused to four phthalimide side walls each carrying a revolving aromatic gate. With the assistance of 1H NMR and UV-vis spectroscopy, we demonstrated that the small 1-methylimidazole guest (12, 94 A3) would coordinate to the interior while the larger 1,5-diadamantylimidazole guest (14, 361 A3) is relegated to the exterior of basket Zn(II)-1. Subsequently, we examined the epoxidation of differently sized and shaped alkenes 18-21 with catalytic baskets 12 in-Mn(III)-1 and 14out-Mn(III)-1 in the presence of the sacrificial oxidant iodosylarene. The epoxidation of cis-stilbene occurred in the cavity of 14out-Mn(III)-1 and at the outer face of 12 in-Mn(III)-1 with the stereoselectivity of the two transformations being somewhat different. Importantly, catalytic basket 14out-Mn(III) -1 was capable of kinetically resolving an equimolar mixture of cis-2-octene 20 and cis-cyclooctene 21 via promotion of the transformation in its cavity.

Chiral cationic [Cp′Mo(CO)2(NCMe)]+ species-catalyst precursors for olefin epoxidation with H2O 2 and tert-butyl hydroperoxide

A novel cyclopentadienyl ligand bearing a chiral oxazoline pendant group (Cpox) has been prepared. Its coordination to molybdenum and tungsten afforded optically pure (R)-CpoxM(I·3-C 3H5)(CO)2 (M = Mo, W) in which the pendant oxazoline fragment is not coordinated to the metal center. Reaction of (R)-CpoxMo(I·3-C3H 5)(CO)2 with tetrafluoroboric acid gives the bidentate I·5-cyclopentadienyloxazoline complex [Cp oxMo(CO)2(NCMe)]BF4 in which the oxazoline is coordinated through the N-atom to the molybdenum center. Their catalytic performance in the epoxidation of cis-cyclooctene, (R)-limonene, and trans-β-methylstyrene with H2O2 and tert-butyl hydroperoxide (TBHP) as oxidants has been studied. (R)-Cp oxW(I·3-C3H5)(CO) 2 displayed high catalytic activity achieving quantitative conversion of cyclooctene epoxide in 2 h with H2O2. [Cp oxMo(CO)2(NCMe)]+ has been shown to be an efficient catalyst with TBHP and H2O2, reaching quantitative conversions of the corresponding epoxide in 30 min and 11 h, respectively. ESI-MS studies of the reaction of [CpoxMo(CO) 2(NCMe)]+ with H2O2 and TBHP revealed the in situ formation of the corresponding peroxido [Cp oxMo(O2)O]+ and dioxido [Cp oxMoO2]+ species, respectively. Further oxidation of these complexes resulted in the loss of the cyclopentadienyloxazoline ligand. Based on spin trap experiments, the involvement of both carbon-and oxygen-centred radicals in the olefin epoxidation catalyzed by [CpoxMo(CO)2(NCMe)]+ has been proved. Copyright

Efficient epoxidation of electron-deficient alkenes with hydrogen peroxide catalyzed by [γ-PW10O38V2(μ-OH) 2]3-

A divanadium-substituted phosphotungstate, [γ-PW10O 38V2(μ-OH)2]3- (I), showed the highest catalytic activity for the H2O2-based epoxidation of allyl acetate among vanadium and tungsten complexes with a turnover number of 210. In the presence of I, various kinds of electron-deficient alkenes with acetate, ether, carbonyl, and chloro groups at the allylic positions could chemoselectively be oxidized to the corresponding epoxides in high yields with only an equimolar amount of H2O2 with respect to the substrates. Even acrylonitrile and methacrylonitrile could be epoxidized without formation of the corresponding amides. In addition, I could rapidly (min) catalyze epoxidation of various kinds of terminal, internal, and cyclic alkenes with H;bsubesubbsubesub& under the stoichiometric conditions. The mechanistic, spectroscopic, and kinetic studies showed that the I-catalyzed epoxidation consists of the following three steps: 1) The reaction of I with H;bsubesubbsubesub& leads to reversible formation of a hydroperoxo species [I;circbsubesubbsubesubbsubesubcirccircbsupesup& (II), 2) the successive dehydration of II forms an active oxygen species with a peroxo group [ 2:2-O2)]3- (III), and 3) III reacts with alkene to form the corresponding epoxide. The kinetic studies showed that the present epoxidation proceeds via III. Catalytic activities of divanadium-substituted polyoxotungstates for epoxidation with H 2O2 were dependent on the different kinds of the heteroatoms (i.e., Si or P) in the catalyst and I was more active than [γ-SiW10O38V2(μ-OH)2] 4-. On the basis of the kinetic, spectroscopic, and computational results, including those of [γ-SiW10O38V 2(μ-OH)2]4-, the acidity of the hydroperoxo species in II would play an important role in the dehydration reactivity (i.e., k3). The largest k3 value of I leads to a significant increase in the catalytic activity of I under the more concentrated conditions. Copyright

CrIII(salen) impregnated on silica for asymmetric ring opening reactions and its recovery via desorption/re-impregnation

The impregnation of CrIII(salen) complexes on silica resulted in a heterogeneous catalyst for the asymmetric ring opening (ARO) reaction of epoxides with good selectivity and acceptable activity. As became apparent from a series of 10 successive batch tests in the ARO reaction of 1,2-epoxyhexane, leaching was limited, while catalytic activity and selectivity were acceptable. Though the support suffered from abrasion in the batch reactor, 80% of the catalyst was easily recoverable via simple extraction from the used solid catalyst and entirely transferable onto a fresh carrier via impregnation. It was shown that 80% of the leached catalyst at the end of the tests could be transformed into a fresh heterogeneous catalyst as well.

Halogenated Terpenoids. XXVII. Dibromo Epoxy Derivatives of (R)-(+)-Limonene

Six dibromo epoxides related to limonene are reported.The synthesis and separation of these isomers allows an improved synthesis of the pure diastereomeric 8,9-epoxides of limonene.

The Diastereomeric 8,9-Epoxides of Limonene (The 8,9-Epoxy-p-menth-1-enes

The stereochemistry of the 8,9-epoxy-p-menth-1-enes has been unambiguously determined by relating them to the corresponding p-menth-1-ene-8,9-diols (uroterpenol) of known configuration.Mild conditions for the hydrolysis of epoxides with hydroxide ion are described.