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.
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.
Method for catalytically synthesizing isooctyl p-methoxycinnamate
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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.
