88927-00-8Relevant academic research and scientific papers
Ruthenium-Catalyzed E-Selective Partial Hydrogenation of Alkynes under Transfer-Hydrogenation Conditions using Paraformaldehyde as Hydrogen Source
Fetzer, Marcus N. A.,Tavakoli, Ghazal,Klein, Axel,Prechtl, Martin H. G.
, p. 1317 - 1325 (2021/02/11)
E-alkenes were synthesized with up to 100 % E/Z selectivity via ruthenium-catalyzed partial hydrogenation of different aliphatic and aromatic alkynes under transfer-hydrogenation conditions. Paraformaldehyde as a safe, cheap and easily available solid hydrogen carrier was used for the first time as hydrogen source in the presence of water for transfer-hydrogenation of alkynes. Optimization reactions showed the best results for the commercially available binuclear [Ru(p-cymene)Cl2]2 complex as pre-catalyst in combination with 2,2-bis(diphenylphosphino)-1,1-binaphthyl (BINAP) as ligand (1 : 1 ratio per Ru monomer to ligand). Mechanistic investigations showed that the origin of E-selectivity in this reaction is the fast Z to E isomerization of the formed alkenes. Mild reaction conditions plus the use of cheap, easily available and safe materials as well as simple setup and inexpensive catalyst turn this protocol into a feasible and promising stereo complementary procedure to the well-known Z-selective Lindlar reduction in late-stage syntheses. This procedure can also be used for the production of deuterated alkenes simply using d2-paraformaldehyde and D2O mixtures.
Hydrogen-bond-assisted transition-metal-free catalytic transformation of amides to esters
Huang, Changyu,Li, Jinpeng,Wang, Jiaquan,Zheng, Qingshu,Li, Zhenhua,Tu, Tao
, p. 66 - 71 (2020/11/18)
The amide C-N cleavage has drawn a broad interest in synthetic chemistry, biological process and pharmaceutical industry. Transition-metal, luxury ligand or excess base were always vital to the transformation. Here, we developed a transition-metal-free hydrogen-bond-assisted esterification of amides with only catalytic amount of base. The proposed crucial role of hydrogen bonding for assisting esterification was supported by control experiments, density functional theory (DFT) calculations and kinetic studies. Besides broad substrate scopes and excellent functional groups tolerance, this base-catalyzed protocol complements the conventional transition-metal-catalyzed esterification of amides and provides a new pathway to catalytic cleavage of amide C-N bonds for organic synthesis and pharmaceutical industry. [Figure not available: see fulltext.]
Oxidative esterification of alcohols by a single-side organically decorated Anderson-type chrome-based catalyst
Wang, Jingjing,Jiang, Feng,Tao, Chaofu,Yu, Han,Ruhlmann, Laurent,Wei, Yongge
supporting information, p. 2652 - 2657 (2021/04/21)
The direct esterification of alcohols with non-noble metal-based catalytic systems faces great challenges. Here, we report a new chrome-based catalyst stabilized by a single pentaerythritol decorated Anderson-type polyoxometalate, [N(C4H9)4]3[CrMo6O18(OH)3C{(OCH2)3CH2OH}], which can realize the efficient transformation from alcohols to esters by H2O2oxidation in good yields and high selectivity without extra organic ligands. A variety of alcohols with different functionalities including some natural products and pharmaceutical intermediates are tolerated in this system. The chrome-based catalyst can be recycled several times and still keep the original configuration and catalytic activity. We also propose a reasonable catalytic mechanism and prove the potential for industrial applications.
A Straightforward Conversion of Activated Amides and Haloalkanes into Esters under Transition-Metal-Free Cs 2 CO 3 /DMAP Conditions
Chen, Liuqing,Gu, Ying,Jian, Junsheng,Liu, Yueping,Miao, Liqiong,Wang, Zijia,Zeng, Zhuo
, p. 4078 - 4084 (2019/10/28)
The esterification of activated amides, N -acylsaccharins, under transition-metal-free conditions with good functional group tolerance has been developed, resulting in C-N cleavage leading to efficient synthesis of a variety of esters in moderate to good yields. This work demonstrates that esterification may proceed by using simple N -acylsaccharins, haloalkanes, and Cs 2 CO 3 as oxygen source.
Aldehydes as potential acylating reagents for oxidative esterification by inorganic ligand-supported iron catalysis
Yu, Han,Wang, Jingjing,Wu, Zhikang,Zhao, Qixin,Dan, Demin,Han, Sheng,Tang, Jiangjiang,Wei, Yongge
supporting information, p. 4550 - 4554 (2019/08/21)
The oxidative esterification of various aldehydes with alcohols could be achieved by a heterogeneous iron(iii) catalyst supported on a ring-like POM inorganic ligand under mild conditions, affording the corresponding esters, including several drug molecules and natural products, in high yields. ESI-MS and control experiments demonstrated that POM-FeV(O) was the active catalytic species and the plausible mechanism was presented. More importantly, the 6th run of the iron catalyst recycles shows only a slight decrease in the yield.
Method for generating ester through reaction of benzoyl chloride and halogenated hydrocarbon
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Paragraph 0036; 0037; 0038, (2017/08/31)
The invention discloses a method for generating ester through reaction of benzoyl chloride and halogenated hydrocarbon. According to the method, benzoyl chloride, halogenated hydrocarbon and carbonate which are reaction substrates are heated and stirred to react in the presence of a catalyst 4-dimethylaminopyridine (DMAP) in an air or inert gas atmosphere to generate a corresponding ester product. The method disclosed by the invention has the beneficial effects that benzoyl chloride, halogenated hydrocarbon and carbonate are taken as the reaction substrates for the first time, carbonate is found as a source of oxygen in the product for the first time, and the reaction is found as a free radical mechanism for the first time.
METHOD OF CONVERTING ALCOHOL TO HALIDE
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Page/Page column 53; 110, (2017/01/02)
The present invention relates to a method of converting an alcohol into a corresponding halide. This method comprises reacting the alcohol with an optionally substituted aromatic carboxylic acid halide in presence of an N-substituted formamide to replace a hydroxyl group of the alcohol by a halogen atom. The present invention also relates to a method of converting an alcohol into a corresponding substitution product. The second method comprises: (a) performing the method of the invention of converting an alcohol into the corresponding halide; and (b) reacting the corresponding halide with a nucleophile to convert the halide into the nucleophilic substitution product.
An Effective Method for the Construction of Esters Using Cs2CO3 as Oxygen Source
Ren, Lanhui,Wang, Lianyue,Lv, Ying,Li, Guosong,Gao, Shuang
supporting information, p. 5172 - 5175 (2015/11/24)
An effective method for the construction of esters from acyl chloride and halohydrocarbon using Cs2CO3 as an oxygen source was achieved for the first time. The methodology has a wide scope of substrates and can be scaled up. The study of a preliminary reaction mechanism demonstrated that the O in the products comes from Cs2CO3 and this esterification proceeds through a free radical reaction. It was also found that CO2 can also be used in this esterification reaction as an oxygen source.
Solvent-free esterification of carboxylic acids and alcohols in the presence of silphos [PCl3-n(SiO2)n] as a heterogeneous phosphine reagent
Rao, Ambati Narasimha,Ganesan, Kumaran,Shinde, Chandra Kant
experimental part, p. 2299 - 2308 (2012/06/18)
An efficient solvent-free method for the preparation of esters from various aromatic and aliphatic acids with primary, secondary, and tertiary alcohols using a heterogeneous phosphine reagent, silphos [PCl3-n(SiO 2)n], in good yields is reported.
[IrCl(cod)]2-catalyzed direct oxidative esterification of aldehydes with alcohols
Kiyooka, Syun-ichi,Wada, Yosuke,Ueno, Mahuyu,Yokoyama, Takeshi,Yokoyama, Reiko
, p. 12695 - 12701 (2008/03/14)
[IrCl(cod)]2 catalyzed the oxidative esterification of a variety of aldehydes with methanol as a solvent in combination with K2CO3 under mild conditions (rt, 12 h). The oxidative esterification reaction of aliphatic aldehydes also took place with olefinic alcohols as reagents in toluene under similar conditions.
