97-85-8Relevant articles and documents
Disproportionation of aliphatic and aromatic aldehydes through Cannizzaro, Tishchenko, and Meerwein–Ponndorf–Verley reactions
Sharifi, Sina,Sharifi, Hannah,Koza, Darrell,Aminkhani, Ali
, p. 803 - 808 (2021/07/20)
Disproportionation of aldehydes through Cannizzaro, Tishchenko, and Meerwein–Ponndorf–Verley reactions often requires the application of high temperatures, equimolar or excess quantities of strong bases, and is mostly limited to the aldehydes with no CH2 or CH3 adjacent to the carbonyl group. Herein, we developed an efficient, mild, and multifunctional catalytic system consisting AlCl3/Et3N in CH2Cl2, that can selectively convert a wide range of not only aliphatic, but also aromatic aldehydes to the corresponding alcohols, acids, and dimerized esters at room temperature, and in high yields, without formation of the side products that are generally observed. We have also shown that higher AlCl3 content favors the reaction towards Cannizzaro reaction, yet lower content favors Tishchenko reaction. Moreover, the presence of hydride donor alcohols in the reaction mixture completely directs the reaction towards the Meerwein–Ponndorf–Verley reaction. Graphic abstract: [Figure not available: see fulltext.].
Metal complex catalysts and method for catalytically reducing carboxylic acids
-
Paragraph 0085-0144; 0149; 0150; 0167-0168; 0178-0179, (2020/06/20)
The invention relates to a metal complex catalyst, which contains at least one of metal complexes with a chemical formula comprising a structural unit represented by a formula I. According to the invention, the center metal of the metal complex catalyst is iridium, and the metal complex catalyst is composed of pentamethylcyclopentadienyl, a bitetrahydropyrimidine ligand and proper coordination anions; the metal complex catalyst has activity on a carboxylic acid reduction reaction, and a carboxylic acid compound is reduced into an alcohol compound in the presence of hydrogen; and the method ismild in reaction condition, can be carried out at room temperature, and is good in catalytic performance and high in reduction product yield.
Preparation method of long-chain ester
-
Paragraph 0072; 0073; 0074; 0075; 0076; 0077-0093, (2019/03/23)
The invention relates to the field of organic synthesis and provides a preparation method of long-chain ester, which comprises the following steps: carrying out esterification reaction of the carboxylic acid and the alcohol through a catalyst and obtaining a long-chain ester phase and a water phase post the standing and layering of the reaction liquid; the catalyst comprises ionic liquid or eutectic solvent; purifying and separating the long-chain ester phase to obtain high-purity long-chain ester; introducing the residual substance again into the esterification reaction system for reaction after the water in the water phase is removed. The yield and the purity of the long-chain ester prepared by the invented method are as high as 99.8% and 99% respectively as indicated by the embodiment of the preparation method.
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.
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.
Manganese Pincer Complexes for the Base-Free, Acceptorless Dehydrogenative Coupling of Alcohols to Esters: Development, Scope, and Understanding
Nguyen, Duc Hanh,Trivelli, Xavier,Capet, Frédéric,Paul, Jean-Fran?ois,Dumeignil, Franck,Gauvin, Régis M.
, p. 2022 - 2032 (2017/08/14)
Aliphatic PNP pincer-supported earth-abundant manganese(I) dicarbonyl complexes behave as effective catalysts for the acceptorless dehydrogenative coupling of a wide range of alcohols to esters under base-free conditions. The reaction proceeds under neat conditions, with modest catalyst loading and releasing only H2 as byproduct. Mechanistic aspects were addressed by synthesizing key species related to the catalytic cycle (characterized by X-ray structure determination, multinuclear (1H, 13C, 31P, 15N, 55Mn) NMR, infrared spectroscopy, inter alia), by studying elementary steps connected to the postulated mechanism, and by resorting to DFT calculations. As in the case of related ruthenium and iron PNP catalysts, the dehydrogenation results from cycling between the amido and amino-hydride forms of the PNP-Mn(CO)2 scaffold. For the dehydrogenation of alcohols into aldehydes, our results suggest that the highest energy barrier corresponds to the hydrogen release from the amino-hydride form, although its value is close to that of the outer-sphere dehydrogenation of the alcohol into aldehyde. This contrasts with the ruthenium and iron catalytic systems, where dehydrogenation of the substrate into aldehyde is less energy-demanding compared to hydrogen release from the cooperative metal-ligand framework.
Rethinking the Claisen–Tishchenko Reaction
Morris, Stacey A.,Gusev, Dmitry G.
supporting information, p. 6228 - 6231 (2017/05/19)
Pincer-type complexes [OsH2(CO){PyCH2NHCH2CH2NHPtBu2}] and [OsH2(CO){HN(CH2CH2PiPr2)2}] catalyze the disproportionation reaction of aldehydes via an outer-sphere bifunctional mechanism achieving turnover frequencies up to 14 000 h?1. The N?H group of the catalysts is a key player in this process, elucidated with the help of DFT calculations.
Method for treating isobutyrate-containing wastewater by alcohol etherification
-
Paragraph 0033; 0034; 0035; 0036; 0037; 0041; 0042, (2016/12/26)
The invention discloses a method for treating isobutyrate-containing wastewater by alcohol etherification, comprising the following steps: 1), acidifying isobutyrate-containing wastewater with concentrated sulfuric acid, adding alcohol, subjecting a reaction system to etherification under reflux condition so as to generate isobutyrate, and stopping reacting until no water is generated in the reaction system; 2), cooling reaction liquid obtained in step 1) to room temperature, re-adding water separated from the reaction system and obtained in step 1), into the cooled reaction liquid, and stirring and standing to obtain oil phase and water phase; subjecting the water phase to solid-liquid separation to obtain low-COD wastewater and sulfate; 3), rectifying the oil phase obtained in step 2); collecting an alcohol fraction and an isobutyrate fraction. The wastewater treated by the method has low COD value.
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).
CATALYST CAPABLE OF FORMING 2,5-DIMETHYLHEXENES
-
Paragraph 0052, (2015/09/23)
A process of making a catalyst and the catalyst composition made by that process comprising a multinuclear metal compound of the formula Ma(PCy3)b(H)c(CO)d(OR)e(H2O)f with molar ratios a:b:c:d:e:f, wherein a is in the range from 2 to 2000, b is in the range from 0 to 4000, c is in the range from 0 to 6000 and d is in the range from 0 to 2000, e is in the range from 1 to 2000, and f is in the range from 0 to 100; wherein PCy3 indicates tricyclohexylphosphine, H indicates hydride, R is an alkyl group determined by the alcohol utilized and H2O is water from the reaction; and a is at least twice w. A method of making one or more 2,5-dimethylhexenes is described. A method of making p-xylene using one or more 2,5-dimethylhexenes is also described.
