- Olefin Metathesis, p-Cresol, and the Second Generation Grubbs Catalyst: Fitting the Pieces
-
p-Cresol as additive to the Grubbs second generation catalyst (GII) allows the cross-metathesis of acrylates with prop-1-en-1-ylbenzenes under conditions that only give the prop-1-en-1-ylbenzene self-metathesis product in the absence of cresol. NMR and IR spectroscopy, MALDI-TOF MS and XPS supported the formation of a ruthenium benzylidene with hydrogen bonds between p-cresol and the chloride ligands of GII. XPS furthermore confirmed p-cresol to increase the binding energies of the GII Ru 3d5/2, 3d3/2, 3p3/2 and 3p1/2 photoelectron lines, whereas 1H NMR spectroscopy indicated the carbene carbon and hydrogen to be shielded. It is thus postulated that p-cresol allows for more facile interaction between electron-deficient compounds and the ruthenium benzylidene by decreasing the electron density on the metal center and increasing the electron density on the carbene.
- Swart, Marthinus R.,Twigge, Linette,Erasmus, Elizabeth,Marais, Charlene,Bezuidenhoudt, Barend C. B.
-
supporting information
p. 1752 - 1762
(2021/05/06)
-
- Mimics of Pincer Ligands: An Accessible Phosphine-Free N-(Pyrimidin-2-yl)-1,2-azole-3-carboxamide Framework for Binuclear Pd(II) Complexes and High-Turnover Catalysis in Water
-
We report for the first time cyclic phosphine-free "head to tail"N,N,N pincer-like (pincer complexes mimicking) N-(pyrimidin-2-yl)-1,2-azole-3-carboxamide Pd(II) complexes with deprotonated amide groups as high-turnover catalysts (TON up to 106, TOF up to 1.2 × 107 h-1) for cross-coupling reactions on the background of up to quantitative yields under Green Chemistry conditions. The potency of the described catalyst family representatives was demonstrated in Suzuki-Miyaura, Mizoroki-Heck, and Sonogashira reactions on industrially practical examples. Corresponding ligands could be synthesized based on readily available reagents through simple chemical transformations. Within the complex structures, a highly unusual 1,3,5,7-tetraza-2,6-dipalladocane frame could be observed.
- Bumagin, Nikolay A.,Dikusar, Evgenij A.,Ivashkevich, Ludmila S.,Kletskov, Alexey V.,Kolesnik, Iryna A.,Lyakhov, Alexander S.,Petkevich, Sergey K.,Potkin, Vladimir I.
-
supporting information
(2020/08/12)
-
- S,O-Functionalized Metal-Organic Frameworks as Heterogeneous Single-Site Catalysts for the Oxidative Alkenylation of Arenes via C-H activation
-
Heterogeneous single-site catalysts can combine the precise active site design of organometallic complexes with the efficient recovery of solid catalysts. Based on recent progress on homogeneous thioether ligands for Pd-catalyzed C-H activation reactions, we here develop a scalable metal-organic framework-based heterogeneous single-site catalyst containing S,O-moieties that increase the catalytic activity of Pd(II) for the oxidative alkenylation of arenes. The structure of the Pd?MOF-808-L1 catalyst was characterized in detail via solid-state nuclear magnetic resonance spectroscopy, N2 physisorption, and high-angle annular dark field scanning transmission electron microscopy, and the structure of the isolated palladium active sites could be identified by X-ray absorption spectroscopy. A turnover frequency (TOF) of 8.4 h-1 was reached after 1 h of reaction time, which was 3 times higher than the TOF of standard Pd(OAc)2, ranking Pd?MOF-808-L1 among the most active heterogeneous catalysts ever reported for the nondirected oxidative alkenylation of arenes. Finally, we showed that the single-site catalyst promotes the oxidative alkenylation of a broad range of electron-rich arenes, and the applicability of this heterogeneous system was demonstrated by the gram-scale synthesis of industrially relevant products.
- Bals, Sara,Bugaev, Aram L.,Dallenes, Jesse,De Vos, Dirk E.,Henrion, Micka?l,Krajnc, Andra?,Liu, Pei,Mali, Gregor,Soldatov, Alexander V.,Van Velthoven, Niels
-
p. 5077 - 5085
(2020/05/27)
-
- Method for catalytically synthesizing isooctyl p-methoxycinnamate
-
The invention discloses a method for catalytic synthesis of isooctyl p-methoxycinnamate, which comprises the following steps: reacting p-methoxycinnamic acid and isooctyl alcohol which are used as rawmaterials in the presence of a solid acid catalyst for 2-6 hours to synthesize isooctyl p-methoxycinnamate. According to the method, isooctyl p-methoxycinnamate and isooctyl alcohol are used as raw materials, the catalyst is solid acid, and the method has the characteristics of mild reaction conditions, simple equipment and the like, and has a good practical application prospect.
- -
-
Paragraph 0022-0027
(2020/01/14)
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- Cross metathesis with acrylates: N-heterocyclic carbene (NHC)- versus cyclic alkyl amino carbene (CAAC)-based ruthenium catalysts, an unanticipated influence of the carbene type on efficiency and selectivity of the reaction
-
Olefin metathesis has been widely explored as a handle for chemical diversification, a feature critical across chemical sectors. Cross metathesis (CM) with acrylic acid derivatives is an example of important but, due to the low catalyst's efficiency, industrially non-utilized transformation. Here we report on systematic evaluation of ruthenium-based catalysts bearing N-heterocyclic carbene (NHC) or cyclic alkyl amino carbene (CAAC) ligands in cross metathesis with methyl acrylate. Dramatic influence of the carbene type on the reaction's efficiency and selectivity has been found. Density functional theory (DFT) calculations suggest that the kinetic selectivity is the main factor differentiating NHC- and CAAC-based ruthenium complexes. Productive turnover number (TON) of 49 900 at 10 ppm loading of nitro-substituted Hoveyda-Grubbs complex (nitro-Grela catalyst) was obtained in the studied reaction, representing the highest efficiency reported to date for this transformation. High efficiency and selectivity of nitro-Grela catalyst was then utilized in cross metathesis of trans-anethole with 2-ethylhexyl acrylate to efficiently produce octyl methoxycinnamate (86 % yield), an antioxidant used in sunscreen formulations.
- Kaczanowska, Katarzyna,Trzaskowski, Bartosz,Peszczyńska, Aleksandra,Tracz, Andrzej,Gawin, Rafa?,Olszewski, Tomasz K.,Skowerski, Krzysztof
-
p. 6366 - 6374
(2020/10/28)
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- Palladium-Based Catalysts Supported by Unsymmetrical XYC–1 Type Pincer Ligands: C5 Arylation of Imidazoles and Synthesis of Octinoxate Utilizing the Mizoroki–Heck Reaction
-
A series of new unsymmetrical (XYC–1 type) palladacycles (C1–C4) were designed and synthesized with simple anchoring ligands L1–4H (L1H = 2-((2-(4-methoxybenzylidene)-1-phenylhydrazinyl)methyl)pyridine, L2H = N,N-dimethyl-4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono)methyl)aniline, L3H = N,N-diethyl-4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono)methyl) aniline and L4H = 4-(4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazono) methyl)phenyl)morpholine H = dissociable proton). Molecular structure of catalysts (C1–C4) were further established by single X-ray crystallographic studies. The catalytic performance of palladacycles (C1–C4) was explored with the direct Csp2–H arylation of imidazoles with aryl halide derivatives. These palladacycles were also applied for investigating of Mizoroki–Heck reactions with aryl halides and acrylate derivatives. During catalytic cycle in situ generated Pd(0) nanoparticles were characterized by XPS, SEM and TEM analysis and possible reaction pathways were proposed. The catalyst was employed as a pre-catalyst for the gram-scale synthesis of octinoxate, which is utilized as a UV-B sunscreen agent.
- Maji, Ankur,Singh, Ovender,Singh, Sain,Mohanty, Aurobinda,Maji, Pradip K.,Ghosh, Kaushik
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p. 1596 - 1611
(2020/04/29)
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- Base-Controlled Heck, Suzuki, and Sonogashira Reactions Catalyzed by Ligand-Free Platinum or Palladium Single Atom and Sub-Nanometer Clusters
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The assumption that oxidative addition is the key step during the cross-coupling reaction of aryl halides has led to the development of a plethora of increasingly complex metal catalysts, thereby obviating in many cases the exact influence of the base, which is a simple, inexpensive, and necessary reagent for this paramount transformation. Here, a combined experimental and computational study shows that the oxidative addition is not the single kinetically relevant step in different cross-coupling reactions catalyzed by sub-nanometer Pt or Pd species, since the reactivity control is shifted toward subtle changes in the base. The exposed metal atoms in the cluster cooperate to enable an extremely easy oxidative addition of the aryl halide, even chlorides, and allow the base to bifurcate the coupling. With sub-nanometer Pd species, amines drive to the Heck reaction, carbonate drives to the Sonogahira reaction, and phosphate drives to the Suzuki reaction, while for Pt clusters and single atoms, good conversion is only achieved using acetate as a base. This base-controlled orthogonal reactivity with ligand-free catalysts opens new avenues in the design of cross-coupling reactions in organic synthesis.
- Fernández, Estefanía,Rivero-Crespo, Miguel A.,Domínguez, Irene,Rubio-Marqués, Paula,Oliver-Meseguer, Judit,Liu, Lichen,Cabrero-Antonino, María,Gavara, Rafael,Hernández-Garrido, Juan C.,Boronat, Mercedes,Leyva-Pérez, Antonio,Corma, Avelino
-
p. 1928 - 1940
(2019/02/14)
-
- Green clean production process of isooctyl p-methoxycinnamate
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The invention relates to a green clean production process of isooctyl p-methoxycinnamate. The green clean production process comprises the following steps: dissolving isooctyl acetate and p-methoxybenzaldehyde in a solvent, and carrying out a reaction under the action of a catalyst to generate isooctyl p-methoxycinnamate; and treating produced wastewater, and recovering byproducts. According to the method, the wastewater is treated, and the OMC wastewater is effectively converted into useful EHA, OMC and industrial anhydrous sodium sulfate meeting national standards in China, so resourceful treatment of the OMC wastewater is achieved, green clean production of OMC is realized, reaction loss is avoided, OMC production can be circularly conducted, and the manufacturing cost of the OMC is greatly reduced.
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-
Paragraph 0085-0087; 0099-0104
(2019/12/25)
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- Utilization of Synthetic Calcium-Phyllosilicates as Bifunctional Bases in the Matsuda-Heck Reaction
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Calcium-phyllosilicates can successfully be used as novel bases in the Matsuda-Heck reaction using methanol as solvent. The new experimental set-up distinguishes itself by higher reactivity and better selectivity compared to other systems.
- Brunner, Heiko,Vedder, Lennart
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p. 698 - 702
(2019/01/04)
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- A Palladium NNC-Pincer Complex as an Efficient Catalyst Precursor for the Mizoroki?Heck Reaction
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The Mizoroki?Heck reaction of aryl halides (iodides, bromides, or chlorides) with activated alkenes in the presence of a palladium NNC-pincer complex at ppb to ppm loadings gave the corresponding internal alkenes in excellent yields. The total turnover number and turnover frequency reached up to 8.70×108 and 1.21×107 h?1 (3.36×103 s?1), respectively. The catalyst was applied in a ten-gram-scale synthesis of the UV-B sunscreen agent octinoxate (2-ethylhexyl 4-methoxycinnamate). Reaction-rate analyses, transmission electron microscopic examination of the reaction mixture, and poisoning tests suggested that a monomeric palladium species is the catalytically active species in the catalytic cycle. (Figure presented.).
- Hamasaka, Go,Ichii, Shun,Uozumi, Yasuhiro
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supporting information
p. 1833 - 1840
(2018/04/05)
-
- An expedient stereoselective synthesis of (E)-α,β-unsaturated esters and thioesters using FeCl3·6H2O
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Facile and convenient synthesis of α,β-unsaturated esters and thioesters from alkylidene derivatives of Meldrum's Acid is described. This method uses catalytic amount of FeCl3·6H2O (0.001–0.005?equiv) with alcohols/thiols (1?equiv) in dry CH3NO2 followed by catalytic amount of piperidine. A variety of α,β-unsaturated esters and thioesters have been synthesized with high E-stereoselectivity in good to excellent yields. The application of this methodology is demonstrated by gram scale synthesis of octinoxate, a sunscreen agent, and other p-methoxycinnamate esters.
- Mohite, Amar R.,Mete, Trimbak B.,Bhat, Ramakrishna G.
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p. 770 - 774
(2017/03/31)
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- Preparation method and application of octyl methoxycinnamate
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The invention discloses a preparation method of octyl methoxycinnamate (OMC). The preparation method comprises the following steps: firstly, uniformly stirring p-methoxybenzaldehyde, acetate, organic amine substances and a solvent, and controlling the temperature to be from 20 DEG C below zero to 10 DEG C; then dropwise adding a titanium tetrachloride catalyst, and after dropwise addition, rising the temperature to 10 to 40 DEG C, and carrying out reaction for 2 to 16h; after the reaction is completed, washing a reaction solution with dilute acid until being neutral, washing with water, drying an organic phase with anhydrous sodium sulfate, and carrying out solvent removal to obtain the octyl methoxycinnamate, wherein the yield reaches 98 percent or above. The preparation method has the characteristics of simpleness, convenience, easiness in control and industrial production, small environmental pollution, low energy consumption, capability of recycling materials, high purity and the like. The prepared octyl methoxycinnamate has the advantages of being colorless and transparent, high purity and the like and can be applied to the field of sun-screening cosmetics, chemical industry for daily supplies, plastics, rubber, coatings and the like.
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Paragraph 0055; 0056; 0057; 0058; 0059; 0060
(2017/07/20)
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- A sun-screening agent to the methoxy cinnamic acid process of isooctyl ester (by machine translation)
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The invention relates to a sun-screening agent to the methoxy cinnamic acid isooctyl (OMC) clean synthetic process. The process adopts a one-pot preparation of methoxy cinnamic acid isooctyl: in a small amount of toluene sulfonic acid under the catalysis of the methyl acetate and isooctanol under isooctyl ester exchange reaction to produce acetic acid, then, in the sodium methoxide under the catalysis of the formaldehyde with the methoxyl condensation reaction, generating to the methoxy cinnamic acid ester. This invention adopts the advanced good ester exchange reaction and then condensation reaction process flow of expensive raw materials to help to improve the utilization rate of the methoxy benzaldehyde, in the process of synthesis does not use any other solvent, no waste water is produced, safety and environmental protection, and the product yield is as high as 97% or more. (by machine translation)
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Paragraph 0024-0033
(2018/04/01)
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- p-Cymene as Solvent for Olefin Metathesis: Matching Efficiency and Sustainability
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The underexploited biorenewable p-cymene is employed as a solvent for the metathesis of various substrates. p-Cymene is a nontoxic compound that can be obtained in large amounts as a side product of the cellulose and citrus industry. For the cross-metathesis of estragole with methyl acrylate, this solvent prevents the consecutive double-bond isomerization of the product and affords the best yield of all solvents tested. Undesired consecutive isomerization is a major challenge for many substrates in olefin metathesis, including pharmaceutical precursors, and the use of p-cymene as a solvent may be a way to prevent it. This solvent results in a better metathesis performance than toluene for the three substrates tested in this work, matching its performance for two other substrates.
- Granato, Artur V.,Santos, Alexandra G.,dos Santos, Eduardo N.
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p. 1832 - 1837
(2017/04/27)
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- Overcoming Catalyst Decomposition in Acrylate Metathesis: Polyphenol Resins as Enabling Agents for PCy3-Stabilized Metathesis Catalysts
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Phosphine-stabilized metathesis catalysts are among the most popular and widely used catalysts in organic synthesis. The second-generation Grubbs catalyst GII, in particular, dominates synthetic applications of olefin metathesis. This is commonly true even for reactions that are fundamentally incompatible with free PCy3, which is released upon entry of GII into the catalytic cycle. A leading example is cross-metathesis with electron-deficient olefins such as acrylates, for which yields are seriously degraded by a deleterious side reaction involving attack of free PCy3 on the acrylate olefin, and production of an enolate anion that decomposes the active catalyst. Here we describe a simple, powerful means of upgrading the performance of GII and its indenylidene analogue M2 to levels matching or exceeding that of the important, but more costly, phosphine-free Hoveyda catalyst HII. Key to this improvement is carrying out the reaction in the presence of a phenol-functionalized polymer resin. We demonstrate that, at standard catalyst loadings (which correspond to low concentrations of PCy3), the beneficial effect of phenol arises not from protonation of PCy3 itself, but from protonation of the enolate, thereby converting this aggressive base into an innocuous phosphonium salt. The methodology is showcased in the demanding cross-metathesis of the renewable phenylpropanoid trans-anethole with 2-ethylhexyl acrylate (an efficient route to the high-value antioxidant octylmethoxycinnamate, an active ingredient in sunscreen formulations with the tradename Octinoxate), as well as methyl acrylate, a ubiquitous and more sterically accessible coupling partner. Experiments with water-saturated toluene indicate that water cannot be substituted for the resin as a sacrificial proton donor, such treatment resulting in drastically reduced productivity. Control experiments involving macrocyclization indicate that the resin has an additional protective function beyond enolate quenching, potentially due to hydrogen bonding of polar contaminants present as impurities in the reagents or reaction medium.
- Santos, Alexandra G.,Bailey, Gwendolyn A.,Dos Santos, Eduardo N.,Fogg, Deryn E.
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p. 3181 - 3189
(2017/06/09)
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- Preparation method for isooctyl p-methoxy cinnamate sun-screening agent
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The invention belongs to the field of chemical industry, and discloses a preparation method for an isooctyl p-methoxy cinnamate sun-screening agent. The method comprises the following steps that p-anisaldehyde, acetic acid ester, a sodium alkoxide solution and isooctyl alcohol are mixed and stirred to be uniform, and reacting is performed for 3-8 hours at the temperature of 55 DEG C-75 DEG C; the pH is adjusted to 12-14 through non-oxidative acid, reacting is performed for 2-8 hours after the pressure is reduced and the temperature is increased to 70 DEG C-110 DEG C, solvent with the low boiling point is recycled, reaction liquid is washed to be neutral through acid, solvent removing and rectifying are performed to obtain the isooctyl p-methoxy cinnamate, and isooctyl alcohol is recycled. According to the technology, the raw material cost is lowered, operation and procedures are simplified, the viscosity in the reaction process can be effectively decreased, and the requirements for equipment are reduced.
- -
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Paragraph 0040; 0041
(2016/11/17)
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- Attractive aerobic access to the α,β-unsaturated acyl azolium intermediate: Oxidative NHC catalysis via multistep electron transfer
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To replace high molecular weight oxidants with air (O2) we introduce multistep electron transfer NHC catalysis. The method provides a general and selective oxidation of the α,β-unsaturated aldehyde derived homoenolate to the synthetically useful α,β-unsaturated acyl azolium intermediate. Several independent oxidative NHC-catalyzed reactions are viable with this strategy and the products can be isolated in high to excellent yields.
- Ta,Axelsson,Sundén
-
supporting information
p. 686 - 690
(2016/02/12)
-
- METHOD FOR COUPLING A FIRST COMPOUND TO A SECOND COMPOUND
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The present disclosure describes a method of coupling a first compound to a second compound, the method comprising: providing the first compound having a fluorosulfonate substituent; providing the second compound comprising an alkene; and reacting the first compound and the second compound in a reaction mixture, the reaction mixture including a catalyst having at least one group 10 atom, the reaction mixture under conditions effective to couple the first compound to the second compound.
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Paragraph 0047; 0048; 0049; 0050; 0052; 0053
(2016/05/02)
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- Tandem catalysis: Versus one-pot catalysis: Ensuring process orthogonality in the transformation of essential-oil phenylpropenoids into high-value products via olefin isomerization-metathesis
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Conversion of essential-oil allylbenzenes (phenylpropenoids) to high-value fine chemicals via isomerization-metathesis is reported. The target reaction sequence involves isomerization of ArCH2CH=CH21 into the corresponding conjugated olefins 2, and ensuing cross-metathesis with acrylates to generate ArCH=CHCO2R 3. The second-generation Hoveyda catalyst HII was chosen for the metathesis step. A range of lead candidates was assessed for the isomerization step, of which most active was the Grotjahn catalyst [CpRu(PN)(MeCN)]PF6([4]PF6; PN = 2-PiPr2-4-tBu-1-Me-imidazole). The following order of isomerization activity was determined, using the isomerization of estragole 1a to anethole 2a (Ar = p-MeOC6H4) as a probe reaction: [CpRu(PN)(MeCN)]PF6> RuHCl(CO)(PPh3)3> Ru(Me-allyl)2(COD) > Pd2Br2(PtBu3)2> RuHCl(PPh3)3> RuCl3(μ2-C)(μ2,κ1-C,η6-Mes-H2IMes)Ru(H)(H2IMes) (the "Grubbs hydride") > RuHCl(CO)(H2IMes)(PCy3) > RuHCl(CO)(IMes)(PCy3) > RuHCl(CO)(PCy3)2. To maximize process efficiency, a systematic comparison of orthogonal tandem catalysis versus sequential catalyst addition was undertaken, using catalysts [4]PF6and HII. The impact of each process type on product selectivity and catalyst compatibility was assessed. Selectivity was undermined in tandem isomerization-metathesis by competing metathesis of 1. Sequential catalyst addition eliminated this problem. The isomerization catalyst [4]PF6adversely affected metathesis yields when equimolar with HII, an effect traced to the imidazole functionality in [4]PF6. However, at the low catalyst loadings required for efficient isomerization (0.1 mol% [4]PF6), negligible impact on metathesis yields was evident. The target cinnamates and ferrulates were obtained in quantitative yields by coupling these steps in a one-pot isomerization-metathesis protocol.
- Higman, Carolyn S.,De Araujo,Fogg, Deryn E.
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p. 2077 - 2084
(2016/04/26)
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- Improving reactivity and selectivity of aqueous-based Heck reactions by the local hydrophobicity of phosphine ligands
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Modification of a triarylphosphine with a cholate moiety affords a new ligand, 1, which is effective in palladium-catalyzed Heck cross-couplings between acrylates and aryl iodides under mild, aqueous reaction conditions. High yields, up to 99%, were achieved in water at 40 °C. In competition studies, a more hydrophobic substrate (n-Bu acrylate) was preferred over the least hydrophobic substrate (methyl acrylate), supportive of a localized hydrophobic microenvironment near the catalytic center. The enhanced reactivity and selectivity for hydrophobic substrates disappeared when the local hydrophobicity was eliminated using a standard water-soluble phosphine or in organic solvents.
- Roberts, Gina M.,Zhang, Shiyong,Zhao, Yan,Woo, L. Keith
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p. 8263 - 8270
(2015/10/05)
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- METHOD FOR PRODUCING 4-METHOXY CINNAMIC ACID 2-ETHYLHEXYL COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for producing a 4-methoxy cinnamic acid 2-ethylhexyl compound friendly for the environment under mild conditions using an inexpensive reagent. SOLUTION: A 4-methoxy cinnamic acid 2-ethylhexyl compound is obtained through: a first step in which a 4-hydroxy cinnamic acid amide compound is treated with a methylation agent to obtain a 4-methoxy cinnamic acid amide compound; a second step in which the 4-methoxy cinnamic acid amide compound is hydrolyzed with acid or a base to obtain a 4-methoxy cinnamic acid compound; and a third step in which the 4-methoxy cinnamic acid compound and the 2-ethyl-1-hexanol are condensed to form an ester linkage. COPYRIGHT: (C)2015,JPOandINPIT
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- General Olefin Synthesis by the Palladium-Catalyzed Heck Reaction of Amides: Sterically Controlled Chemoselective N-C Activation
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Metal-catalyzed reactions of amides proceeding via metal insertion into the N-CO bond are severely underdeveloped due to resonance stabilization of the amide bond. Herein we report the first Heck reaction of amides proceeding via highly chemoselective N-CO cleavage catalyzed by Pd0 utilizing amide bond ground-state destabilization. Conceptually, this transformation provides access to a myriad of metal-catalyzed transformations of amides via metal insertion/decarbonylation.
- Meng, Guangrong,Szostak, Michal
-
supporting information
p. 14518 - 14522
(2016/01/25)
-
- Method to reduce substantivity of cloth staining caused by sunscreens
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Suggested is a cosmetic and/or pharmaceutical preparation, especially dermatological preparation and its used for the protection of the human skin and human hair against the harmful effects of ultraviolet solar radiation comprising the water soluble UVA absorbing substance disodium phenyl dibenzimidazole tetrasulfonate, wherein the preparation is free from the UVA filters selected from the group consisting of 2,4-bis[{(4-(2-ethylhexyloxy)-2-hydroxy}phenyl]--6-(4-methoxyphenyl)-1,3,5-triazine, (Tinosorb?S), hexyl 2-(4-diethylamino-2-hydroxybenzoyl)benzoate (Uvinul? A Plus), 2-hydroxy-4-methoxybenzo-phenone (Benzophenone-3, Oxybenzone, Neo Heliopan? BB), Tris-Biphenyl Triazine (Tinosorb? A2B) or mixtures thereof.
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- "nok": A phytosterol-based amphiphile enabling transition-metal-catalyzed couplings in water at room temperature
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The third-generation designer amphiphile/surfactant, "Nok" (i.e., SPGS-550-M; β-sitosterol methoxypolyethyleneglycol succinate), soon to be commercially available from Aldrich, can be prepared in two steps using an abundant plant feedstock and β-sitosterol, together with succinic anhydride and PEG-550-M. Upon dissolution in water, it forms nanomicelles that serve as nanoreactors, which can be characterized by both cryo-TEM and dynamic light scattering analyses. Several transition-metal-catalyzed reactions have been run under micellar conditions to evaluate this surfactant relative to results obtained in nanoparticles composed of TPGS-750-M (i.e., a second-generation surfactant). It is shown that Nok usually affords yields that are, in general, as good or better than those typically obtained with TPGS-750-M, and yet is far less costly.
- Klumphu, Piyatida,Lipshutz, Bruce H.
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p. 888 - 900
(2014/03/21)
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- Cosmetic compositions
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Suggested is a cosmetic compositions comprising (a) a crosspolymer obtained from copolymerisation of at least two different polyols and at least one dicarboxylic acid and (b) at least one fragrance.
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- A composition for lightening skin and hair
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Suggested is a composition comprising (a) sclareolide and (b1) at least one tyrosinase inhibitor; and/or (b2) at least one sun protection factor; and/or (b3) at least one anti-oxidants; and/or (b4) at least one anti-inflammatory agent; and/or (b5) at least one desquamating agent.
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- Water-stabilized three- and four-atom palladium clusters as highly active catalytic species in ligand-free C-C cross-coupling reactions
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Elite cliques: Palladium clusters with three and four atoms were found to be the catalytically active species for ligand-free palladium-catalyzed C-C bond-forming reactions (see picture). These palladium cluster species could be stabilized in water and stored for long periods of time for use on demand with no loss of activity. High yields of products and turnover frequencies (TOFs) of up to 105 h-1 were observed. Copyright
- Leyva-Perez, Antonio,Oliver-Meseguer, Judit,Rubio-Marques, Paula,Corma, Avelino
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supporting information
p. 11554 - 11559
(2013/11/06)
-
- An efficient protocol for synthesis of 4-methoxy cinnamate in ionic liquid
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Synthesis of 2-ethylhexyl-4-methoxy cinnamate was carried out efficiently using palladium-catalyzed Heck reaction of 4-bromoanisole and 2-ethylhexylacrylate in tetrabutyl ammonium bromide-based ionic liquid. The ionic liquid was used as a cost-effective reaction medium and the catalyst in it is stable and can be recycled for at least four times without significant loss in activity.
- Wang, Yu Fang,Yang, Qi Chao,Zhang, Bao Ji,Lin, Dong,Zhang, Ming Jie
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p. 489 - 492
(2013/11/06)
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- Chemical plants: High-value molecules from essential oils
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As society faces a future of dwindling petrochemical supplies at increasing cost, much attention has been focused on methods to degrade biomass into renewable commodity-chemical building blocks. Reported here is a powerful complementary approach that amplifies the complexity of molecular structures present in plant materials. Essential-oil phenylpropenoids are transformed via acrylate cross-metathesis into potent antioxidants that are widely used in perfumery and cosmetics, and in treating disorders associated with oxidative damage.
- Lummiss, Justin A. M.,Oliveira, Kelley C.,Pranckevicius, Alexandre M. T.,Santos, Alexandra G.,Dos Santos, Eduardo N.,Fogg, Deryn E.
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supporting information
p. 18889 - 18891
(2013/01/15)
-
- A newly-designed PE-supported arsine for efficient and practical catalytic Wittig olefination
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A newly designed PE-supported arsine has been developed as an excellent catalyst for catalytic Wittig-type olefination. Simple ketones, in particular inactive ketones prove to be suitable substrates for the first time. This reaction provides an easy access to di-, tri-, and tetra-substituted olefins in high yield.
- Wang, Peng,Liu, Chun-Rong,Sun, Xiu-Li,Chen, Shuai-Shuai,Li, Jun-Fang,Xie, Zuowei,Tang, Yong
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supporting information; experimental part
p. 290 - 292
(2012/01/06)
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- AHR MEDIATORS
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The invention relates to a method for finding and assessing agonists [and] antagonists of the aryl hydrocarbon receptor (Ah receptor; AhR), to the agonists and antagonists themselves and to uses thereof
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- Palladium nanoparticles supported on polyvinylpyridine: Catalytic activity in Heck-type reactions and XPS structural studies
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Palladium nanoparticles, obtained by metal vapour synthesis (MVS), were deposited on cross-linked polyvinylpyridine. The Pd/PVPy system showed high catalytic activity in the Heck C{single bond}C coupling reaction of iodo- and bromo-arenes (iodobenzene, bromobenzene, p-nitrobromobenzene, p-bromoacetophenone, p-(methoxy)bromobenzene) with alkyl acrylates (methyl acrylate, n-butyl acrylate, ethylhexyl trans-3-(4-methoxyphenyl)acrylate) at 100 °C-175 °C working under nitrogen atmosphere as well as in air. The catalyst is stable and the leaching of metal in solution is very low. When reused, the recovered Pd/PVPy maintains the catalytic activity of the pristine material. XPS structural studies performed on the starting catalyst as well as on the recovered one indicate the presence of a interaction between the basic nitrogen of the pyridine present in the polymer and the metal.
- Evangelisti, Claudio,Panziera, Nicoletta,Pertici, Paolo,Vitulli, Giovanni,Salvadori, Piero,Battocchio, Chiara,Polzonetti, Giovanni
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experimental part
p. 287 - 293
(2009/05/08)
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- Heck couplings at room temperature in nanometer aqueous micelles
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(Chemical Equation Presented) A nonionic amphiphile such as Triton X-100 or the vitamin E-based PTS, both of which form nanomicelles in water, promotes Heck crosscouplings of non-water-soluble partners at ambient temperatures. These are the first examples of Heck reactions conducted in water (as the only solvent) at room temperature.
- Lipshutz, Bruce H.,Taft, Benjamin R.
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supporting information; experimental part
p. 1329 - 1332
(2009/04/10)
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- A practical, efficient, and atom economic alternative to the Wittig and Horner-Wadsworth-Emmons reactions for the synthesis of (E)-α,β- unsaturated esters from aldehydes
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We describe a highly efficient new methodology for the synthesis of (E)-α,β-unsaturated esters from aldehydes. In our DMAP-catalyzed reaction, both aromatic as well as aliphatic aldehydes furnish the desired products highly regio- and stereoselectively if treated with commercially available or synthetically easily accessible malonic acid half ester. A large scale application in the synthesis of p-methoxycinnamates, which are of use as sunscreen ingredients, is described.
- List, Benjamin,Doehring, Arno,Hechavarria Fonseca, Maria T.,Job, Andreas,Rios Torres, Ramon
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p. 476 - 482
(2007/10/03)
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- Novel nickel-carbene, palladium-carbene and platinum-carbene complexes, their produciton and use in catalytic reactions
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The invention relates to novel monocarbene complexes of nickel, palladium or platinum with electron-deficient olefin ligands, to their preparation and to their use in the homogeneous catalysis of organic reactions.
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Page/Page column 8
(2008/06/13)
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- Method of producing alkoxycinnamic acid ester
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The invention relates to a method of producing alkoxycinnamic acid ester (alkoxy cinnamate) by condensing C5-C8acetic acid esters with C1-C4alkoxybenzaldehyde in the presence of an alkaline and/or alkaline earth C1-C4alcohalate and removing the C1-C4alcohol that is produced by this reaction from the reaction mixture.
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Page column 5
(2008/06/13)
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- Synthetic applications of oxime-derived palladacycles as versatile catalysts in cross-coupling reactions
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Palladacycles 1 and 2, derived from 4,4′-dichlorobenzophenone and 4-hydroxyacetophenone oximes, respectively, are very efficient and versatile pre-catalysts for a wide range of carbon-carbon bond coupling reactions such as, Mizoroki-Heck, Suzuki-Miyaura, Stille, Ullmann-type, Sonogashira, sila-Sonogashira, Glaser and acylation of alkynes under very low loading conditions in air and either in organic or aqueous solvents, employing reagent-grade chemicals. High yielding, general, and practical procedures for the palladium-catalyzed Mizoroki-Heck, Suzuki-Miyaura, Ullmann-type, Sonogashira and sila-Sonogashira reactions are described.
- Alonso, Diego A.,Botella, Luis,Najera,Pacheco, Ma. Carmen
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p. 1713 - 1718
(2007/10/03)
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- Polymer bound Pd(0) phosphine catalyst for homogeneous catalysis
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Facile synthesis of water-soluble polymer bound Pd(0) phosphine catalyst is described. This recyclable polymeric catalyst is soluble in aqueous or aqueous/organic media and has high activity in nucleophilic allylic substitution, Heck reaction and hydrogenation.
- Koshti, Nirmal,Naik, Shubhangi,Parab, Bharat
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p. 852 - 856
(2007/10/03)
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- SUNSCREEN COMPOSITIONS
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The present invention relates to improved sunscreen compositions, more preferably to improved sunscreen compositions containing at least one sunscreening agent (sunscreen) and a silicone-polyamide copolymer.
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- Novel indanylidene compounds
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Novel indanylidene compounds can be used as UV-A filters in cosmetic compositions for protecting skin and hair and for technical applications.
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- Synthesis of monocarbenepalladium(0) complexes and their catalytic behavior in cross-coupling reactions of aryldiazonium salts
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The first monocarbenepalladium(0) complexes with benzoquinone and naphthoquinone as additional ligands have been prepared. As demonstrated by NMR spectroscopy and X-ray analysis, the complexes show a unique coordination mode giving quinone-bridged dimers. The monocarbenepalladium(0) complexes allow efficient cross-coupling reactions of aryldiazonium salts with olefins (Heck reaction) and arylboronic acids (Suzuki reaction).
- Selvakumar, Kumaravel,Zapf, Alexander,Spannenberg, Anke,Beller, Matthias
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p. 3901 - 3906
(2007/10/03)
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- Method for producing olefins
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Olefins containing aromatic substituents are synthesized without the addition of phosphonium salts or phosphanes with the aid of a PdIIcompound as a catalyst in the presence of nitrogen-containing additives such as N,N-dimethylglycine and a base.
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Page column 8
(2008/06/13)
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- A versatile catalyst for heck reactions of aryl chlorides and aryl bromides under mild conditions
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In the presence of Cy2NMe, Pd/P(t-Bu)3 serves as an exceptionally mild and versatile catalyst for Heck reactions of aryl chlorides and bromides. A sterically and electronically diverse array of aryl bromides, as well as activated aryl chlorides, couple with a range of mono- and disubstituted olefins at room temperature, furnishing the arylated product with high E/Z stereoselection. The corresponding reactions of a broad spectrum of electron-neutral and electron-rich aryl chlorides proceed at elevated temperature, also with high selectivity. In terms of scope and mildness, Pd/P(t-Bu)3/Cy2NMe represents an advance over previously reported catalysts for these Heck coupling processes.
- Littke,Fu
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p. 6989 - 7000
(2007/10/03)
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- A new efficient palladium catalyst for Heck reactions of deactivated aryl chlorides
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A new palladium catalyst consisting of Pd(dba)2 and di-1-adamantyl-n-butylphosphine is described for the Heck reaction of non-activated and deactivated aryl chlorides. The new catalyst is more efficient and gives improved results compared to the previously known best catalyst system.
- Ehrentraut,Zapf,Beller
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p. 1589 - 1592
(2007/10/03)
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- Sulphonic acids and their use as UV absorbers
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PCT No. PCT/EP96/04325 Sec. 371 Date Apr. 16, 1998 Sec. 102(e) Date Apr. 16, 1998 PCT Filed Oct. 4, 1996 PCT Pub. No. WO97/14680 PCT Pub. Date Apr. 24, 1997Sulphonic acids of formula (I) in which the components and indices have the meanings given in the description, are eminently suitable as u/v absorbers, especially in cosmetic sun-screening agents.
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- Indanylidene compounds, a process for their preparation and their use as UV absorbers
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Compounds of the formula I according to claim 1 are excellently suitable as UV absorbers for use in cosmetic products, in particular sunscreen compositions, daytime care products and hair care products. They are furthermore suitable for protection of products.
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- Cosmetic skin-care product against ageing of the skin as an effect of light
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The present invention relates to a new cosmetic skin-care product for external use, which is based on UV-radiation-absorbing substances in combination with a free-radical scavenger system.
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- Application of a new combination of palladium and CaCo3 for an aerobic heck reaction using arenediazonium-salts
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Efficient Heck reactions under aerobic conditions were carried out using Pd-catalyst in the presence of CaCO3. Under these conditions a neat Heck Reaction rising arenediazonium salts bearing functional groups including nitro functionalities can generally take place in good yields tip to 95%.
- Brunner, Heiko,De Courcy, Nathalie Le Cousturier,Genet, Jean-Pierre
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p. 4815 - 4818
(2007/10/03)
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- Process for the preparation of cinnamic acid derivatives
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The invention relates to a process for the preparation of cinnamic acid derivatives which involves reacting chlorinated aromatic compounds and acrylic acid derivatives in the presence of palladium catalysts.
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- Cosmetic composition with photoprotective properties
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The invention is directed to a cosmetic composition with synergistically improved photoprotective properties, comprising at least one component selected from the group of Vitamin E, Vitamin C, derivatives of Vitamin E, derivatives of Vitamin C, and combinations of at least two of these components, and at least one natural polyamine or derivative.
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