5912-87-8Relevant academic research and scientific papers
One-pot hydroformylation/O-acylation of propenylbenzenes for the synthesis of polyfunctionalized fragrances
Delolo, Fábio G.,Vieira, Gabriel M.,Villarreal, Jesus A.A.,dos Santos, Eduardo N.,Gusevskaya, Elena V.
, p. 272 - 279 (2020/06/17)
A process involving the hydroformylation/O-acylation of propenylbenzenes with a phenolic group is described for eugenol, isoeugenol, chavicol, propenyl guaethol, 2-allylphenol, and 2-allyl-6-methylphenol. The reactions occur in parallel, under the same reaction conditions in anisole, a solvent with an impressive sustainability rank comparable to those of ethanol and water. The products contain formyl and acetoxy moieties, both established olfactory groups in flavor and fragrance industry, and present potential as new fragrance components with less allergenic properties. To the best of our knowledge, this is the first time that a one-pot process involving hydroformylation combined with further functionalization in a remote site is described.
Method for synthesizing E-methyl styrene compound
-
Page/Page column 7, (2020/03/25)
The method for preparing E-pyridyl or alkyl-substituted,bipyridine, in a solvent, in the presence of nitrogen protection, in, reaction 0 °C -50 °C in the presence of a metal nickel salt 24 - 36h, ligand and an additive is E, and the preparation method disclosed by the invention has the advantages, cheap 2,2 ’ - raw materials, easiness in obtaining 2,2 ’ - and the like. The ligand is,bipyridine or an alkyl-substituted bipyridyl compound, in the. presence of a nitrogen, protection agent, in a solvent.
A Pd-Catalyzed Site-Controlled Isomerization of Terminal Olefins
Ren, Wenlong,Sun, Fei,Chu, Jianxiao,Shi, Yian
supporting information, p. 1868 - 1873 (2020/03/03)
An effective Pd-catalyzed isomerization of olefins with 2-PyPPh2 as the ligand is described. A wide variety of trans-2-olefins bearing various functional groups can be obtained with high regio- A nd stereoselectivity under mild reaction conditions. The ligand is crucial for the reaction.
Hydrophilic (ν6-Arene)-Ruthenium(II) Complexes with P-OH ligands as catalysts for the isomerization of allylbenzenes and C-H bond arylation reactions in water
González-Fernández, Rebeca,Crochet, Pascale,Cadierno, Victorio
, p. 3696 - 3706 (2019/10/11)
Half-sandwich ruthenium(II) complexes containing ν6-coordinated 3-phenylpropanol and phosphinous-acid-type ligands, namely, [RuCl2(ν6-C6H5CH2CH2CH2OH){P(OH)R2}] (R = Me (2a), Ph (2b), 4-C6H4CF3 (2c), 4-C6H4OMe (2d), OMe (2e), OEt (2f), and OPh (2g), have been synthesized in 44-88% yield by reacting [RuCl2{ν6:κ1(O)-C6H5CH2CH2CH2OH}] (1) with the appropriate pentavalent phosphorus oxide R2P(═O)H. The structure of [RuCl2(ν6-C6H5CH2CH2CH2OH){P(OH)Me2}] (2a) was unequivocally confirmed by X-ray diffraction methods. Compounds 2a-g proved to be catalytically active in the isomerization of allylbenzenes into the corresponding (1-propenyl)benzene derivatives employing water as the sole reaction solvent, with [RuCl2(ν6-C6H5CH2CH2CH2OH){P(OH)(OPh)2}] (2g) showing the best performance and a broad substrate scope (73-93% isolated yields with E/Z ratios around 90:10 employing 1 mol % of 2g and 3 mol % of K2CO3, and performing the catalytic reactions at 80 °C for 4-24 h). The results herein presented show for the first time the utility of phosphinous acids as auxiliary ligands for metal-catalyzed olefin isomerization processes, reactions in which a cooperative role for the P - OH unit is proposed. On the other hand, the utility of complexes 2a-g as catalysts for ortho-arylation reactions of 2-phenylpyridine in water is also briefly discussed.
Modular palladium bipyrazoles for the isomerization of allylbenzenes - Mechanistic considerations and insights into catalyst design and activity, role of solvent, and additive effects
Spallek, Markus J.,Stockinger, Skrollan,Goddard, Richard,Trapp, Oliver
experimental part, p. 1466 - 1480 (2012/09/11)
The catalytic activity of novel bidentate N,N-chelated palladium complexes derived from electron excessive, backbone fused 3,3'-bipyrazoles in the selective isomerization of terminal arylpropenoids and 1-alkenes is described. The catalysts are easily modified by appropriate wing tip substitution, while maintaining the same bulky, rigid unreactive aliphatic backbone. Eleven novel palladium complexes with different electronic and steric properties were investigated. Their performance in the palladium(II)-catalyzed isomerization of a series of substituted allylbenzenes was evaluated in terms of electronic as well as steric effects. Besides the clear finding of a general trend towards higher catalyst activity with more electron-donating properties of the coordinated N,N-bidentate ligands, we found that the catalytic process strongly depends on the choice of solvents and additives. Extensive solvent screening revealed that reactions run best in a 2:1 toluene-methanol mixture, with the alcohol employed being a crucial factor in terms of electronic and steric factors. A reaction mechanism involving a hydride addition-elimination mechanism starting with a palladium hydride species generated in situ in alcoholic solutions, as corroborated by experiments using deuterium labeled allylbenzene, seems to be most likely. The proposed mechanism is also supported by the observed reaction rate orders of κobs[cat.]≈1 (0.94), κobs [substrate]=0.20→1.0 (t→∞) and κobs [methanol]=-0.51 for the isomerization of allylbenzene. Furthermore, the influence of acid and base, as well as the role of the halide coordinated to the catalyst, are discussed. The system catalyzes the isomerization of allylbenzenes very efficiently yielding high E:Z selectivities under very mild conditions (room temperature) and at low catalyst loadings of 1 mol% palladium even in unpurified solvents. The integrity and stability of the catalyst system were confirmed by multiple addition reaction cycles, successive filtration and isolation experiments, and the lack of palladium black formation. Copyright
Fast and green microwave-Assisted conversion of essential oil allylbenzenes into the corresponding aldehydes via alkene isomerization and subsequent potassium permanganate promoted oxidative alkene group cleavage
Luu, Thi Xuan Thi,Lam, Trinh To,Le, Thach Ngoc,Duus, Fritz
scheme or table, p. 3411 - 3424 (2010/01/16)
Essential oil allylbenzenes from have been converted quickly and efficiently into the corresponding benzaldehydes in good yields by a two-step "green" reaction pathway based on a solventless alkene group isomerization by KF/Al2O3 to form the corresponding l-arylpropene and a subsequent solventless oxidation of the latter to the corresponding benzaldehyde by KMnO4/CuSO4-5H2O. The assistance by microwave irradiation results in very short reaction times (2O3 under solvent-free conditions, respectively.
Retention behavior of compounds with active hydrogen atoms and their acetylated derivatives in reversed-phase HPLC
Zenkevich,Kosman
, p. 1173 - 1176 (2007/10/03)
In view of poor interlaboratory reproducibility of retention indices I in reversed-phase high-performance liquid chromatography, not the indices themselves but their differences for reactants and products of interaction with various reagents can be used to identify compounds with active hydrogen atoms. For acetylated derivatives of phenols and aromatic amines, the quantity ?I = I(ArXH) -I(ArXCOCH3), where X = O or NH. has statistically significant distinguishable values of 126 ± 15 and 70 ± 20, respectively. The additivity of the parameters ?I is first revealed for the polyfunctional compounds of these classes that are incapable of intramolecular hydrogen bonding. Abnormal ?I values and deviations from the additivity rule are observed only for substances with intramolecular hydrogen bonding. This finding can be used to confirm the presence of relevant structural units in molecules.
Studies on the Cleavage of β-Aryl Ether Bonds in Lignin Model Compounds Effected by Anthrone and its Derivatives
Poppius, Kristiina
, p. 611 - 616 (2007/10/02)
The β-ether cleavage reaction of the phenolic model compound 1, 1-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)-1-propanol, caused by anthrone or 10-methylanthrone in alkaline solution is compared with the degradation reactions of the anthrone adduct 2 and the 10-methylanthrone adduct 3, 1-(4-hydroxy-3-methoxyphenyl)-1-(9-oxo-9,10-dihydro-10-anthryl)-2-(2-methoxyphenoxy)propane and 1-(4-hydroxy-3-methoxyphenyl)-1-(9-oxo-10-methyl-9,10-dihydro-10-anthryl)-2-(2-methoxyphenoxy)propane, respectively.The amounts of the degradation products (guaiacol and trans-isoeugenol) indicate that there possibly is a pathway for the anthrone promoted β-ether cleavage not involving the formation of an adduct. 10,10'-Bianthrone, which was found among the reaction products, also has some ability to cleave β-ether bonds under the chosen conditions.
Adducts of Anthrahydroquinone and Anthranol with Lignin Model Quinone Methides. 1. Synthesis and Characterization
Landucci, Lawrence L.,Ralph, John
, p. 3486 - 3495 (2007/10/02)
Adduct formation of anthrahydroquinone (9,10-dihydroxyanthracene, AHQ) or anthranol (9-hydroxyanthracene) with lignin model quinone methides (4-methylenecyclohexa-2,5-dienones) was established.This reaction is thought to be the key step in AHQ-catalyzed delignification of wood under alkaline pulping conditions.Numerous quinone methides derived from both 1-aryl-2-O-arylethyl and 1-aryl-2-O-arylpropyl lignin models were used.A typical example is the reaction of the quinone methide derived from 1-(3-methoxy-4-hydroxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol with AHQto give the adduct threo-1-(3-methoxy-4-hydroxyphenyl)-1-(10-hydroxy-9-oxoanthracen-10-yl)-2-(2-methoxyphenoxy)propan-3-ol. 1H NMR spectra of the adducts revealed large diamagnetic shifts of the protons in the 1-aryl substituent due to its close approach to the shielding regions of the anthracenyl moiety.This effect dimished with increasing size of the 10-substituent (H to OH to OAc).In AHQ adducts, intense hydrogen bonding between the 10-OH and the ether oxygen of the 2-aryl ether substituent was indicated by a large paramagnetic shift of the hydroxyl proton.The unusually large diamagnetic and paramagnetic shifts reflect a distinct rigidity of the adduct conformation that is more pronounced in the adducts containing a propyl side chain.
Process for preparing methylvanillyl ketone from isoeugenol
-
, (2008/06/13)
Methylvanillyl ketone is prepared from a "through process" involving oxidation of isoeugenol followed by subsequent acidic hydrolysis.
