Xi:Irritant;
80-56-8Relevant articles and documents
Iron Catalyzed Double Bond Isomerization: Evidence for an FeI/FeIII Catalytic Cycle
Woof, Callum R.,Durand, Derek J.,Fey, Natalie,Richards, Emma,Webster, Ruth L.
supporting information, p. 5972 - 5977 (2021/03/17)
Iron-catalyzed isomerization of alkenes is reported using an iron(II) β-diketiminate pre-catalyst. The reaction proceeds with a catalytic amount of a hydride source, such as pinacol borane (HBpin) or ammonia borane (H3N?BH3). Reactivity with both allyl arenes and aliphatic alkenes has been studied. The catalytic mechanism was investigated by a variety of means, including deuteration studies, Density Functional Theory (DFT) and Electron Paramagnetic Resonance (EPR) spectroscopy. The data obtained support a pre-catalyst activation step that gives access to an η2-coordinated alkene FeI complex, followed by oxidative addition of the alkene to give an FeIII intermediate, which then undergoes reductive elimination to allow release of the isomerization product.
Amphiphilic polymeric nanoreactors containing Rh(i)-NHC complexes for the aqueous biphasic hydrogenation of alkenes
Allandrieu, Audrey,Coppel, Yannick,Daran, Jean-Claude,Gayet, Florence,Hromov, Roman,Labande, Agnès,Manoury, Eric,Poli, Rinaldo,Ruzhylo, Illia,Sabatier, Cassandra,Sambou, Sasaline Salomon,Wang, Hui
, p. 6811 - 6824 (2021/10/25)
A rhodium(i) complex bearing a monodentate N-heterocyclic carbene ligand has been confined into the core of amphiphilic polymeric core-crosslinked micelles (CCMs). The Rh complex was covalently bound to the polymeric chains by incorporation of a polymerizable unit on the NHC ligand. Nanoreactor Rh-NHCmes@CCM5bhas been evaluated as a catalyst for the aqueous biphasic hydrogenation of styrene and other alkenes. It has shown a high activity with styrene at a low catalytic loading (10?000/1 substrate/Rh ratio), greater than that of an analogous molecular Rh(i) complex, and its evolution to Rh0is slower. This is attributed to several factors, among which the confinement effect and the favourable polyoxygenated environment of the nanoreactor core. Finally, the CCMs could be recycled up to four times with almost no loss of activity over 3 h cycles and the loss of rhodium per cycle was on average lower than 0.6 ppm.
Method and Means for Releasing a Terpene Mixture to a Cannabis Flower During Storage
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, (2021/09/17)
A method and means for releasing a terpene mixture to a Cannabis flower during storage with may be from a cotton pulp card or a two-way humidity pack with an additional terpene blend for keeping a Cannabis flower fresh while naturally increasing the desired terpene levels. The product is a blend of humidity regulating agents infused with terpenes (plant derived) which allows for the product to be paired with herbal material to increase and maintain the relative humidity, while transferring the flavor/aroma/taste terpenes from the package into the herbal material. There are two embodiments, the first is a Terp Pack+Humidity (“Terp Pack+RH”) which contains a herban material to increase and maintain relative humidity, while releasing the infused terenes, and the second is more simply a Terp Pack (“Terp Pack”) which contains no humidity enhancing material and is only a carrier for releasing the terpene mixture.
Exploring the Keggin-Type Heteropolyacid-Catalyzed Reaction Pathways of the Β-Pinene with Alkyl Alcohols
Polo, Henrique Priori,Lopes, Neide Paloma Goncalves,da Silva, Márcio José
, p. 2844 - 2853 (2019/05/28)
Abstract: In this work, we investigated the activity of Keggin heteropolyacid catalysts (i.e., H3PW12O40, H3PMo12O40 and H4SiW12O40) in β-pinene reactions with alkyl alcohols (i.e. methyl, ethyl, propyl, sec-propyl, butyl and sec-butyl alcohols), and exploring the different aspects that drive the selectivity of this process. We have found that carbon skeletal rearrangements and isomerization providing intermediate carbocations that controlling the reaction selectivity. β-pinene was preferentially converted to α-terpinyl ion which undergoes a nucleophilic attack of alcohol providing alkyl alcohol. Bornyl ion was converted to bornyl and fenchyl ethers. The other secondary products were β-pinene isomers obtained from bornyl and α-terpinyl carbocations. Phosphotungstic acid (i.e., H3PW12O40) was the most active catalyst and selective toward the main product (α-terpinyl alkyl ether); the highest conversion (ca. 96%) and ether selectivity (ca. 61%) was achieved in the reactions with β-pinene. Although having also been alkoxylate, α-pinene was less reactive (ca. 40%), while camphene and limonene remained unreactive under reaction conditions studied. An increase of temperature resulted in an improvement on conversion of β-pinene and selectivity toward α-terpinyl methyl ether. Similarly, the H3PW12O40 concentration played a crucial role on reaction selectivity. This work presents positive features such as a short reaction time, high atom economy, mild reaction conditions (i.e., low temperature and room pressure). Even though soluble the catalyst was easily recovered by liquid -liquid extraction and efficiently reused. Graphical Abstract: [Figure not available: see fulltext.].
Bifunctional catalyst Pd-Al-MCM-41 for efficient dimerization-hydrogenation of β-pinene in one pot
Zhang, Song,Xu, Chao,Zhai, Guoqing,Zhao, Mingliang,Xian, Mo,Jia, Yuxiang,Yu, Zongjiang,Liu, Fusheng,Jian, Fangfang,Sun, Weizhi
, p. 47539 - 47546 (2017/10/19)
A new type of bimetallic palladium and aluminum incorporated mobile crystalline materials (Pd-Al-MCM-41) as bifunctional catalysts has been hydrothermally synthesized. Characterization shows that these molecular materials exhibit an ordered mesoporous structure, high surface area and a good dispersion of palladium in the frame. The catalytic activity of the Pd-Al-MCM-41 for the dimerization-hydrogenation reaction system of β-pinene in one pot has been systematically studied. Pd0.5-Al30-MCM-41 (SiO2/Al2O3 = 30, 0.5 wt% palladium content) was found to be the best catalyst which gave a dimer yield of up to 64.7%. It is worth noting that palladium shows a good synergic catalytic effect with aluminum in the dimerization reaction and enhances the dimerization yield. Furthermore, the bifunctional catalyst displayed a good activity over 4 runs.
Converting S-limonene synthase to pinene or phellandrene synthases reveals the plasticity of the active site
Xu, Jinkun,Ai, Ying,Wang, Jianhui,Xu, Jingwei,Zhang, Yongkang,Yang, Dong
, p. 34 - 41 (2017/03/27)
S-limonene synthase is a model monoterpene synthase that cyclizes geranyl pyrophosphate (GPP) to form S-limonene. It is a relatively specific enzyme as the majority of its products are composed of limonene. In this study, we converted it to pinene or phellandrene synthases after introducing N345A/L423A/S454A or N345I mutations. Further studies on N345 suggest the polarity of this residue plays a critical role in limonene production by stabilizing the terpinyl cation intermediate. If it is mutated to a non-polar residue, further cyclization or hydride shifts occurs so the carbocation migrates towards the pyrophosphate, leading to the production of pinene or phellandrene. On the other hand, mutant enzymes that still possess a polar residue at this position produce limonene as the major product. N345 is not the only polar residue that may stabilize the terpinyl cation because it is not strictly conserved among limonene synthases across species and there are also several other polar residues in this area. These residues could form a “polar pocket” that may collectively play this stabilizing role. Our study provides important insights into the catalytic mechanism of limonene synthases. Furthermore, it also has wider implications on the evolution of terpene synthases.
Support Functionalization with a Phosphine-Containing Hyperbranched Polymer: A Strategy to Enhance Phosphine Grafting and Metal Loading in a Hydroformylation Catalyst
Garcia, Marco A. S.,Heyder, Rodrigo S.,Oliveira, Kelley C. B.,Costa, Jean C. S.,Corio, Paola,Gusevskaya, Elena V.,dos Santos, Eduardo N.,Bazito, Reinaldo C.,Rossi, Liane M.
, p. 1951 - 1960 (2016/07/06)
We present the design of a hydroformylation catalyst through the immobilization of air-stable Rh nanoparticles (NPs) on a magnetic support functionalized with a hyperbranched polymer that bears terminal phosphine groups. The catalyst modification with the hyperbranched polymer improved the metal–support interaction, the metal loading, and the catalytic activity. The catalyst was active for the hydroformylation of natural products, such as estragole, and could be used in successive reactions with negligible metal leaching. The phosphine grafting played a key role in the recyclability of Rh NPs under hydroformylation conditions. The catalytic activity was maintained in successive reactions, even if the catalyst was exposed to air during each recovery procedure. The modification of the support with hyperbranched polyester allowed us either to increase the number of Rh active species or to obtain more active Rh species on the catalyst surface.
Imidazo[1,2-a]pyridine-ylmethyl-derivatives and their use as flavoring agents
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, (2015/03/03)
The present invention primarily relates to imidazo[1,2-a]pyridine-ylmethyl-derivatives of Formula (I) wherein R1, R2, X, W e J are as defined in the description, to mixtures thereof and to the use thereof as flavoring agents. The compounds in accordance with the present invention are suitable for producing, imparting, or intensifying an umami flavor. The invention further relates to flavoring mixtures, compositions for oral consumption as well as ready-to-eat, ready-to-use and semifinished products, comprising an effective amount of the compound of Formula (I) and to specific methods for producing, imparting, modifying and/or intensifying specific flavor impressions.
Unique catalysis of gold nanoparticles in the chemoselective hydrogenolysis with H2: Cooperative effect between small gold nanoparticles and a basic support
Noujima, Akifumi,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
, p. 6723 - 6725 (2012/07/28)
Gold nanoparticles on hydrotalcite act as a heterogeneous catalyst for the chemoselective hydrogenolysis of various allylic carbonates to the corresponding terminal alkenes using H2 as a clean reductant. The combination of gold nanoparticles and basic supports elicited significantly unique and selective catalysis in the hydrogenolysis.
