615-11-2Relevant academic research and scientific papers
Sodium organoaluminate containing bidentate pyrrolyl ligand: Synthesis, structure, and catalytic activity for the Tishchenko reaction
Liu, Yu,Guo, Zhiqiang,Wang, Yakong
, (2021/05/26)
An novel sodium organoaluminate containing bidentate pyrrolyl ligand [C4H3NH(2-CH2NHtBu)] was efficiently synthesized and characterized by X-ray crystallography. The molecular structure shows it is a monodimensional infinite chain structures with linear arrangements. Its basic repeat unit comprises the Al atom bonded to two deprotonated pyrrole rings and Na atom coordinated to of nitrogen atoms of –NtBu fragment, which undergoes further to coordinates a pyrrolyl ring of an adjacent molecule in a ?2-fasion. Furthermore, this sodium organoaluminate exhibited high catalytic activities for Tishchenko reaction.
Synthesis of amides and esters containing furan rings under microwave-assisted conditions
Janczewski, ?ukasz,Zieliński, Dariusz,Kolesińska, Beata
, p. 265 - 280 (2021/03/17)
In this work, we present a novel method for the synthesis of ester and amide derivatives containing furan rings (furfural derivatives) under mild synthetic conditions supported by microwave radiation. N-(Furan-2-ylmethyl)furan-2-carboxamide and furan-2-ylmethyl furan-2-carboxylate were produced using 2-furoic acid, furfurylamine, and furfuryl alcohol. The reactions were carried out in a microwave reactor in the presence of effective coupling reagents: DMT/NMM/TsO? or EDC. The reaction time, the solvent, and the amounts of the substrates were optimized. After crystallization or flash chromatography, the final compounds were isolated with good or very good yields. Our method allows for the synthesis of N-blocked amides using N-blocked amino acids (Boc, Cbz, Fmoc) and amine. As well as compounds with a monoamide and ester moiety, products with diamides and diester bonds (N,N-bis(furan-2-ylmethyl) furan-2,5-dicarboxamide, bis(furan-2-ylmethyl) furan-2,5dicarboxylate, and furan-3,4-diylbis(methylene) bis(furan-2-carboxylate)) were synthesized with moderate yields in the presence of DMT/NMM/TsO– or EDC, using 2,5-furan-dicarboxylic acid and 3,4-bis(hydroxymethyl)furan as substrates.
Base-Free and Acceptorless Dehydrogenation of Alcohols Catalyzed by an Iridium Complex Stabilized by a N, N, N-Osmaligand
Alabau, Roberto G.,Esteruelas, Miguel A.,Martínez, Antonio,Oliván, Montserrat,O?ate, Enrique
, p. 2732 - 2740 (2018/09/10)
The preparation of a N,N,N-osmaligand, its coordination to iridium to afford an efficient catalyst precursor, and the catalytic activity of the latter in dehydrogenation reactions of hydrogen carriers based on alcohols are reported. Complex OsH2Cl2(PiPr3)2 (1) reacts with 3-(2-pyridyl)pyrazol to give the osmium(II) complex 2H, which contains an acidic hydrogen atom. Deprotonation of the latter by the bridging methoxy groups of the dimer [Ir(μ-OMe)(n4-COD)]2 (COD = 1,5-cyclooctadiene) leads to Ir(2)( n 4-COD) (3), where osmaligand 2 has a free-nitrogen atom. Iridium complex 3 catalyzes the dehydrogenation of secondary and primary alcohols to ketones and aldehydes or esters, respectively, and the dehydrogenation of diols to lactones. Cyclooctatriene is detected during the catalysis by GC-MS, suggesting that the true catalyst of the reactions is a dihydride IrH2(2)-species with osmaligand 2 acting as N,N,N-pincer. The presence of a phenyl group in the substrates favors the catalytic processes. The dehydrogenative homocoupling of primary alcohols to esters appears to take place via the transitory formation of hemiacetals.
Synthesis, characterization and catalytic performances of benzimidazolin-2-iminato actinide (IV) complexes in the Tishchenko reactions for symmetrical and unsymmetrical esters
Liu, Heng,Khononov, Maxim,Fridman, Natalia,Tamm, Matthias,Eisen, Moris S.
, p. 123 - 137 (2017/10/25)
A new family of benzimdazolin-2-iminato actinide?(IV) complexes [(Bim7-MeDipp/MeN)An(N(SiMe3)2)3] (An = U (3), Th (4)) and [(Bim4-MeDipp/MeN)An(N(SiMe3)2)3] (An = U (5), Th (6)) were synthesized and their solid state structures were established by single-crystal X-ray diffraction analysis. The catalytic performances of complexes 3–6 towards the homo- and cross-coupling of aldehydes (Tishchenko reaction) were studied and the thorium complexes 4 and 6 displayed moderate to high activities for the production of the corresponding symmetric and unsymmetrical esters. Coupling of aldehyde and alcohols, known as the tandem proton-transfer esterification, and the intermolecular coupling reaction between aldehyde and trifluoromethylketones were also investigated by these thorium complexes, indicating a complementary method to obtain unsymmetrical esters selectively. Plausible mechanisms for these reactions are proposed based on stoichiometric studies.
Furoate cigarette spice, preparation method of furoate cigarette spice and application of furoate cigarette spice to cigarettes
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Paragraph 0026; 0030-0032; 0043-0046, (2021/03/25)
The invention belongs to the technical field of cigarette spice, and particularly relates to furoate cigarette spice, a preparation method of the furoate cigarette spice and application of the furoatecigarette spice to cigarettes. The cigarette spice uses furoic acid as raw materials, and another alcohol containing spice ingredients as ligands; through N,N'-carbonyl di-imidazole activation to synthesize the novel furoate sweet aroma compound; the compound has a simple structure; the synthesis method is simple; the burning smoking process thermal cracking study is performed on the compound; furan ingredients and other substances with unique fragrance features can be obtained through cracking. When the compound is applied to tobacco flavoring, the smoke gas richness can be enhanced; the smoke gas mouthfeel can be coordinated; the miscellaneous qi is reduced; the irritation is reduced; the aftertaste is improved; meanwhile, the mouthfeel such as sweet aroma and fruit aroma can also be obtained during the cigarette smoking evaluation through the spice addition; the smoking quality is improved.
Rhodium-catalyzed synthesis of imines and esters from benzyl alcohols and nitroarenes: Change in catalyst reactivity depending on the presence or absence of the phosphine ligand
Song, Taemoon,Park, Ji Eun,Chung, Young Keun
, p. 4197 - 4203 (2018/04/14)
The [Rh(COD)Cl]2/xantphos/Cs2CO3 system efficiently catalyzes the reductive N-alkylation of aryl nitro compounds with alcohols by a borrowing-hydrogen strategy to afford the corresponding imine products in good to excellent yields. In the absence of xantphos, the [Rh(COD)Cl]2/Cs2CO3 catalytic system behaves as an effective catalyst for the dehydrogenative coupling of alcohols to esters, with nitrobenzene as a hydrogen acceptor. The reactivity of the rhodium catalytic system can be easily manipulated to selectively afford the imine or ester.
Thorium complexes possessing expanded ring N-heterocyclic iminato ligands: Synthesis and applications
Ghatak, Tapas,Drucker, Shani,Fridman, Natalia,Eisen, Moris S.
supporting information, p. 12005 - 12009 (2017/09/25)
Six and seven membered N-heterocyclic iminato ligands (L) are introduced allowing access a new class of Th(iv) complexes of the type Cp?2Th(L)(CH3). These complexes were studied in the Tishchenko reaction. Stoichiometric reactions together with kinetic and thermodynamic studies permit us to propose a plausible mechanism.
Nitrous Oxide as a Hydrogen Acceptor for the Dehydrogenative Coupling of Alcohols
Gianetti, Thomas L.,Annen, Samuel P.,Santiso-Quinones, Gustavo,Reiher, Markus,Driess, Matthias,Grützmacher, Hansj?rg
supporting information, p. 1854 - 1858 (2016/02/03)
The oxidation of alcohols with N2O as the hydrogen acceptor was achieved with low catalyst loadings of a rhodium complex that features a cooperative bis(olefin)amido ligand under mild conditions. Two different methods enable the formation of either the corresponding carboxylic acid or the ester. N2 and water are the only by-products. Mechanistic studies supported by DFT calculations suggest that the oxygen atom of N2O is transferred to the metal center by insertion into the Rh-H bond of a rhodium amino hydride species, generating a rhodium hydroxy complex as a key intermediate.
The promoted Tishchenko reaction and catalytic intermediate by 2-aminopyrrolyl dilithium compounds
Guo, Zhiqiang,Wei, Xuehong,Tong, Hongbo,Chao, Jianbin,Liu, Diansheng
supporting information, p. 73 - 76 (2015/03/14)
The dimerization of aldehydes to the analogous carboxylic esters (Tischenko reaction) has been achieved in impressive yields using the dilithium compounds containing bidentate di-anionic pyrrolyl ligands as initiators. The initiated intermediate {[2-(tBuNCH)C4H3NLi][PhCH2OLi(TMEDA)]}2 was isolated and characterized by satisfactory C, H and N microanalysis, 1H, 13C{1H} and 7Li NMR spectra in pyridine-d5 at ambient temperature, and single crystal X-ray structural data. The processes involve a redox reaction of 2-aminopyrrolyl dilithium compound with aldehyde.
Mixed Imidazolin-2-iminato-Cp? Thorium(IV) Complexes: Synthesis and Reactivity Toward Oxygen-Containing Substrates
Karmel, Isabell S. R.,Fridman, Natalia,Tamm, Matthias,Eisen, Moris S.
supporting information, p. 2933 - 2942 (2015/06/30)
The mixed pentamethylcyclopentadienyl thorium(IV) imidazolin-2-iminato complexes Cp?2Th(ImDippN)(Me) (2) and Cp?2Th(ImMesN)(Me) (3) were synthesized in quantitative yields via rapid protonolysis of Cp?2Th(Me)2 (1) with the respective neutral imidazolin-2-iminato ligand ImRNH. Cp?2Th(ImDippN)(Me) (2) and Cp?2Th(ImMesN)(Me) (3) display short Th-N bond lengths and large Th-N-C angles. The reactivity of complex 2 and 3 toward oxygen-containing substrates was studied, and the catalytic activity of 2 was compared to the dimethyl (bispentamethyl-cyclopentadienyl) thorium complex 1. Complex 2 was applied in the catalytic Tishchenko reaction with aromatic, heteroaromatic, and branched aliphatic aldehydes, displaying a higher catalytic activity than Cp?2Th(Me)2 and Cp?2Th(ImMesN)(Me). Furthermore, 2 was applied as a catalyst in the crossed Tishchenko reaction and in the oligomerization of bis(aldehydes), as well as in the ring-opening polymerization of ε-caprolactone. In all reactions, the activity of Cp?2Th(ImDippN)(Me) (2) and Cp?2Th(ImMesN)(Me) (3) was higher than that observed for Cp?2Th(Me)2 (1), which can be attributed to the increased electron density introduced by the coordination of the imidazolin-2-iminato ligand. (Chemical Equation Presented).
