- Selective Catalytic Hydrogenation in the presence of Lanthanide tris-β-Diketonates as "Protecting" Reagents
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The selectivity of >C=C double bonds catalytic hydrogenation increases considerably in the presence of some lanthanide tris-β-diketonates for those unsaturated aldehydes and ketones possessing highly susceptible to reduction carbonyl group.It is a result of the selective co-ordination between the lanthanide complex added and the carbonyl group of a substrate.In most cases the complete protection of carbonyl groups is observed if the complex is added in equimolar amount to the substrate.A number of lanthanum tris-β-diketonates have been tested; the complexes with fluorinated ligands were demonstrated to ensure the highest selectivity of the hydrogenation.The correlation between the constants of equilibrium in reaction mixture and "protecting" activity of the complexes is discussed.A few examples demostrate the practical utilization of the lanthanum tris-β-diketonates to the selective hydrogenation of unsaturated aldehydes and ketones.
- Komarov, Igor V.,Denisenko, Victor E.,Kornilov, Mikhail Yu.
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- Asymmetric α-Allylation of Aldehydes with Alkynes by Integrating Chiral Hydridopalladium and Enamine Catalysis
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A palladium-catalyzed asymmetric α-allylation of aldehydes with alkynes has been established by integrating the catalysis of enamine and chiral hydridopalladium complex that is reversibly formed from the oxidative addition of Pd(0) to chiral phosphoric acid. The ternary catalyst system, consisting of an achiral palladium complex, a primary amine, and a chiral phosphoric acid allows the reaction to tolerate a wide scope of α,α-disubstituted aldehydes and alkynes, affording the corresponding allylation products in high yields and with excellent levels of enantioselectivity.
- Su, Yong-Liang,Li, Lu-Lu,Zhou, Xiao-Le,Dai, Zhen-Yao,Wang, Pu-Sheng,Gong, Liu-Zhu
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p. 2403 - 2406
(2018/04/27)
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- Ru-Catalyzed Cross-Dehydrogenative Coupling between Primary Alcohols to Guerbet Alcohol Derivatives: With Relevance for Fragrance Synthesis
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A simple method has been developed for the cross dehydrogenative coupling between two different primary alcohols using readily available RuCl2(PPh3)3 as a precatalyst through the borrowing-hydrogen approach. The present methodology is applicable to a large variety of alcohol derivatives including long chain aliphatic alcohols and heteroaryl alcohols. In addition, the methodology was applied in a straightforward protocol to synthesize commercially available fragrances such as Rosaphen and Cyclamenaldehyde in good yields.
- Manojveer, Seetharaman,Salahi, Saleh,Wendt, Ola F.,Johnson, Magnus T.
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p. 10864 - 10870
(2018/09/06)
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- A synthetic route to 4-alkyl-α-methylhydrocinnamylaldehydes
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The 4-Alkyl-α-methylhydrocinnamylaldehydes (alkyl-isopropyl, isobutyl, methyl) are frequently used fragrances with desired floral (lilac, cyclamen, lily-of-the-valley) scent. These substances are valued for their good stability in basic solution and, therefore, are frequently used in soaps, detergents, or shampoos. These substances are synthesized by a two-step synthesis involving base catalyzed aldol condensation of 4-alkylbenzaldehyde with propanal followed by selective hydrogenation of the C=C bond. In aldol condensation, selectivity is decreased by formation of undesired products of propanal autocondensation 2-methylpent-2-enal. In this work the reaction conditions for homogenous catalyzed aldol condensation of 4-isobutylbenzadehyde with propanal were tested (catalyst type and amount, molar ratio of reactants, solvent type). Reaction conditions giving the best results (92% conversion, 79% selectivity) were adapted to other 4-alkyl-α-methylcinnamylaldehydes preparation with similar results. In the second step—hydrogenation of aldol product different types of catalyst (nickel, cobalt, palladium or Adkins catalyst), and also different solvents, were tested. Hydrogenation conditions leading to the highest yield (72% selectivity at 95% conversion) were adapted to other 4-alkylhydrocinnamyladehydes with similar results.
- Vrbková, Eva,Vysko?ilová, Eli?ka,Rott, Martin,Zapletal, Martin,?erveny, Libor
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p. 2603 - 2613
(2017/03/22)
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- rabbit ear oxaldehyde a method of production
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The invention relates to a cyclamen aldehyde production method. The method concretely comprises the following steps: mixing methylacrolein dipropionic acid with isopropyl benzene, slowly adding a titanium tetrachloride and trifluoromethanesulfonic acid mixed solution in a dropwise manner at a low temperature while stirring, reacting, slowly pouring a diluted hydrochloric acid solution into the above obtained reaction solution after completing the reaction, hydrolyzing, taking the obtained organic phase, adding sodium hydroxide and methanol, carrying out a de-esterification reaction, washing by using water after completing the de-esterification reaction, separating the obtained organic layer, and rectifying the above obtained crude product to obtain highly pure cyclamen aldehyde. An innovative titanium tetrachloride and catalytic amount trifluoromethanesulfonic acid double-acid catalysis mode is adopted, the concrete dropwise addition sequence, the reaction time and the temperature are limited, so side reactions are reduced, and the purity of the cyclamen aldehyde is improved; and isopropyl benzene is cheap and easily available, and can be simultaneously used as a solvent and a reactant without adding other solvents, so the method disclosed in the invention has great advantages in cost and three-waste control.
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Paragraph 0020; 0021
(2016/10/10)
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- Industrial production method of high-content cyclamen aldehyde
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The invention discloses a production method of high-content cyclamen aldehyde, relating to the technical field of fine chemical engineering production. After isopropyl benzene and propionyl chloride used as initial raw materials are subjected to acylation reaction, selective hydrogenation is carried out to synthesize cyclamen aldehyde, so the method has the advantages of accessible raw materials and high yield. Ethanol is used as an organic solvent for hydrogenation reaction, thereby overcoming the defects of incomplete reaction or excess hydrogenation and inactivation of the recycled catalyst in the hydrogenation process, and controlling the content of ortho-cyclamen aldehyde of the side reaction at 0.5% or below. Besides, a high-vacuum falling film fractionating tower is used for separating and purifying the cyclamen aldehyde, so that the cyclamen alcohol content in the cyclamen aldehyde finished product is controlled at 0.5% or below; and thus, the singlet content in the final product reaches 98.5% or above, and the final product has pure and soft fragrance and satisfies the requirement for essence blending.
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Paragraph 0047-0072
(2017/07/04)
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- Method for synthesizing high-content cyclamen aldehyde spice
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The invention discloses a method for synthesizing a high-content cyclamen aldehyde spice, and relates to the technical field of fine chemical engineering. Cumin and propionyl chloride are catalyzed by lewis acid to be subjected to an acylation reaction, and isopropyl benzene acetone is generated; then isopropyl benzene acetone and phosphorus oxychloride are subjected to an acylation reaction, and after distillation and purification, the product, ethyl alcohol, hydrogen and a catalyst are subjected to a hydrogenation reaction; after the reaction is completed, a cyclamen aldehyde crude product is subjected to flashing and fractionation, ethyl alcohol is recycled, and finally spice-grade cyclamen aldehyde is obtained. The content of ortho-position cyclamen aldehyde and cyclamen alcohol in cyclamen aldehyde is controlled to be below 0.5%, and therefore the final product is pure and soft in fragrance and meets the requirements of flavor blending of flavors and fragrances.
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Paragraph 0038; 0054; 0070-0078
(2017/02/17)
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- An efficient TiCl4-catalysed method for the synthesis of para-substituted aromatic aldehydes
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An efficient and highly selective synthesis of para-substituted aromatic aldehydes has been achieved by TiCl4-catalysed Friedel-Crafts alkylation of monosubstituted benzenes with methacrolein diacetyl acetal.
- Zhou, Chenfeng,Su, Weike
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p. 555 - 557
(2015/11/27)
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- Cyclamen aldehyde synthesis: Aldol condensation followed by hydrogenation over ruthenium catalyst
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Cyclamen aldehyde is a fragrant substance with the scent of cyclamen or lily-of-the-valley. In this work, the desired cyclamen aldehyde was prepared by twostep synthesis. At the first step, aldol condensation of 4-isopropylbenzaldehyde and propanal was carried out. The influence of used catalyst (potassium hydroxide and sodium methoxide) and propanal amount were tested. Propanal was used in excess and it was added to the reaction mixture dropwise (to prevent its self-condensation to 2-methylpent-2-enal). Resulting mixture of 4-isopropylbenzaldehyde and forcyclamen aldehyde was hydrogenated using different Ru/C catalysts. The products detected in hydrogenation reaction mixture were: desired cyclamen aldehyde, cyclamen alcohol and forcyclamen alcohol. The influence of catalyst type and amount, reaction temperature and hydrogen pressure on the reaction course was tested. The highest yield (19.4 %) was obtained using pressure 10 MPa, temperature 110 °C and 2 wt% of catalyst Ru/C.
- Vrbkov, Eva,Skpala, Tom,Vyskoilov, Elika,erven, Libor
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p. 9195 - 9205
(2015/03/04)
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- Microwave-assisted organocatalytic cross-aldol condensation of aldehydes
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An environmentally benign organocatalytic cross-aldol condensation of aldehydes under microwave irradiation in the absence of solvent is described. Using pyrrolidine as a catalyst, an efficient and sustainable atom economic method was developed for the cross-aldol condensation of various aldehydes with excellent results. Among the products, jasmine aldehyde, α-hexyl cinnamaldehyde and cyclamen aldehyde, three compounds of great industrial demand, were synthesised.
- Limnios, Dimitris,Kokotos, Christoforos G.
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p. 4496 - 4499
(2013/05/09)
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- LILIAN SURROGATE
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Due to toxicological concerns, it may be desirable to replace the fragrance compound lilial with less problematic compounds without losing the creative power and quality regarding perfumes. The present invention addresses this need by using selected oxazolidines described herein.
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- NOVEL DEORDORISING COMPOSITIONS AND DEODORISING PRODUCTS CONTAINING SAME
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The invention relates to novel deodorant compositions containing at least one compound of the family of acetylenic ketones and the deodorant products containing them. A particularly preferred composition according to the invention comprises at least one compound of the family of the α-acetylenic ketones and a mixture of aldehydes chosen from two different families.
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- Mild and chemoselective synthesis and deprotection of geminal diacetates catalyzed by titanium(IV) halides
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A novel, mild, and chemoselective method was developed for the preparation of gem-diacetates from aldehydes and acetic anhydride in the presence of titanium(IV) fluoride (1-5 mol%) under solvent-free conditions at room temperature. The reaction showed a high chemoselectivity toward aldehydes in the presence of ketones. Moreover, titanium(IV) fluoride also catalyzed the deprotection of gem-diacetates to the corresponding aldehydes in water. This efficient and simple method has several benefits, including the use of an inexpensive catalyst, solvent-free conditions, mild reaction temperatures, and high yields, which make it both cost-effective and environmentally friendly. Georg Thieme Verlag Stuttgart.
- Jung, Misuk,Yoon, Jieun,Kim, Hak Sung,Ryu, Jae-Sang
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experimental part
p. 2713 - 2720
(2010/10/02)
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- Oxidative coupling of benzenes with α,β-unsaturated aldehydes by the Pd(OAc)2/molybdovanadophosphoric acid/O2 system
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The oxidative coupling reaction of benzene with an α,β- unsaturated aldehyde was examined by the combined catalytic system of Pd(OAc)2 with molybdovanadophosphoric acid (HPMoV) under atmospheric dioxygen. Thus, the reaction of benzene with acrolein under dioxygen (1 atm) by the use of catalytic amounts of Pd(OAc)2 and H4PMo 11VO40·26H2O in the presence of dibenzoylmethane as a ligand in propionic acid at 90 °C for 1.5 h afforded cinnamaldehyde in 59% yield and β-phenylcinnamaldehyde in 5% yield. This catalytic system was extended to the direct oxidative coupling through the C-H bond activation of various arenes with acrolein and methacrolein.
- Yamada, Tomoyuki,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 5471 - 5474
(2008/04/18)
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- Functional fragrance precursor
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The present invention relates to a class of fragrance precursor compounds comprising one or more of the compounds derived from the reaction of X—OH and an aldehyde or ketone, said fragrance precursor compounds being of the formula X—O—C(R) (R*) (OR**) wherein R is a C6-24 alkyl group, a C6-24 aralkyl group or a C6-24 alkaryl group; R* is H or a C6-24 alkyl group, a C6-24 aralkyl group or a C6-24 alkaryl group; R** is H or X; X—O representing a moiety derived from X—OH, and wherein X—OH is a compound selected from the group consisting of surfactants, fabric softeners, softener precursor ester amines, softener precursor amido amines, hair conditioners, skin conditions, saccharides and polymers. In a second aspect it relates to a method of preparing such precusors. Further the invention relates to compositions, comprising the precursor of the invention.
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- From allylic alcohols to saturated carbonyls using Fe(CO)5 as catalyst: Scope and limitation studies and preparation of two perfume components
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The direct conversion of allylic alcohols to saturated carbonyls, using Fe(CO)5 as a catalyst, offers good synthetic potential. Mono-, di- and even trisubstituted alkenes bearing various alkyl, aryl and electronwithdrawing groups on the allylic system give good to excellent yields of rearranged products. Limitations occur mainly with polyunsaturated derivatives. This reaction was applied to a short and efficient synthesis of cyclamen aldehyde and foliaver.
- Cherkaoui, Hassan,Soufiaoui, Mohammed,Grée, René
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p. 2379 - 2383
(2007/10/03)
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- HYDROGENATION OF CYCLAMEN ALDEHYDE AND LILY ALDEHYDE PRECURSORS ON SUPPORTED METAL CATALYSTS.
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Cyclamen and lily aldehydes, which are widely used in the perfumery and cosmetics industry, are obtained by selective saturation of the double bond in 3-(4-isopropylphenyl)-2-methyl-2-propenal (cyclamen aldehyde precursor) and 3-(tert-butylphenyl)-2-methyl-2-propenal (lily aldehyde precursor). This paper reports the results of hydrogenation of cyclamen and lily aldehide precursors on supported catalysts in which the active phase was rhodium or nickel. Hydrogenation of cyclamen aldehyde precursor to cyclamen aldehyde on 5% Rh/Al//2O//3 or 30% Ni/SiO//2 proceeds with 95-99% selectivity; the selectivity of hydrogenation of lily aldehyde precursor is lower, owing to the specific characteristics of its structure.
- Pak,Konuspaev,Sagindykov,Sokol'skii,Zapletal,Prykhlik
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p. 1058 - 1060
(2007/10/02)
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- HYDROGENATION OF 3-(4-ISOPROPYLPHENYL)-2-METHYL-2-PROPENAL TO YIELD 3-(4-ISOPROPYLPHENYL)-2-METHYLPROPANAL ON PALLADIUM CATALYST
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A study is carried out on the hydrogenation of 3-(4-isopropylphenyl)-2-methyl-2-propenal to yield 3-(4-isopropylphenyl)-2-methylpropanal on Pd/Al2O3 catalysts with various amounts of palladium in ethanol in the pressure range from 1 to 100 atm.We determined conditions for the selective hydrogenation of the ethylenic bond conjugated with the carboxylic group; the selectivity was 96-98percent.
- Pak, A. M.,Ginzburg, M. A.,Turganbaeva, S. M.,Gabdrakipov, V. Z.,Kartonozhkina, O. I.,et al.
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p. 1040 - 1043
(2007/10/02)
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