5466-77-3Relevant articles and documents
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
Kaczanowska, Katarzyna,Trzaskowski, Bartosz,Peszczyńska, Aleksandra,Tracz, Andrzej,Gawin, Rafa?,Olszewski, Tomasz K.,Skowerski, Krzysztof
, p. 6366 - 6374 (2020)
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.
Olefin Metathesis, p-Cresol, and the Second Generation Grubbs Catalyst: Fitting the Pieces
Swart, Marthinus R.,Twigge, Linette,Erasmus, Elizabeth,Marais, Charlene,Bezuidenhoudt, Barend C. B.
supporting information, p. 1752 - 1762 (2021/05/06)
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.
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
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)
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.
Palladium-Based Catalysts Supported by Unsymmetrical XYC–1 Type Pincer Ligands: C5 Arylation of Imidazoles and Synthesis of Octinoxate Utilizing the Mizoroki–Heck Reaction
Maji, Ankur,Singh, Ovender,Singh, Sain,Mohanty, Aurobinda,Maji, Pradip K.,Ghosh, Kaushik
, p. 1596 - 1611 (2020/04/29)
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.
S,O-Functionalized Metal-Organic Frameworks as Heterogeneous Single-Site Catalysts for the Oxidative Alkenylation of Arenes via C-H activation
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)
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.
Method for catalytically synthesizing isooctyl p-methoxycinnamate
-
Paragraph 0022-0027, (2020/01/14)
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.
Base-Controlled Heck, Suzuki, and Sonogashira Reactions Catalyzed by Ligand-Free Platinum or Palladium Single Atom and Sub-Nanometer Clusters
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)
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.
Utilization of Synthetic Calcium-Phyllosilicates as Bifunctional Bases in the Matsuda-Heck Reaction
Brunner, Heiko,Vedder, Lennart
, p. 698 - 702 (2019/01/04)
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.
Green clean production process of isooctyl p-methoxycinnamate
-
Paragraph 0085-0087; 0099-0104, (2019/12/25)
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.
A Palladium NNC-Pincer Complex as an Efficient Catalyst Precursor for the Mizoroki?Heck Reaction
Hamasaka, Go,Ichii, Shun,Uozumi, Yasuhiro
supporting information, p. 1833 - 1840 (2018/04/05)
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.).
