728-99-4Relevant academic research and scientific papers
Hf(OTf)4 as a highly potent catalyst for the synthesis of Mannich bases under solvent-free conditions
Gong, Shan-Shan,Han, Shuai-Bo,Liu, Rong,Peng, Xiao-Chong,Sun, Qi,Wei, Jing-Ying
, (2020/01/28)
Hf(OTf)4 was identified as a highly potent catalyst (0.1–0.5 mol%) for three-component Mannich reaction under solvent-free conditions. Hf(OTf)4-catalyzed Mannich reaction exhibited excellent regioselectivity and diastereoselectivity when alkyl ketones were employed as substrates. 1H NMR tracing of the H/D exchange reaction of ketones in MeOH-d4 indicated that Hf(OTf)4 could significantly promote the keto-enol tautomerization, thereby contributing to the acceleration of reaction rate.
two chlorine two luxuriant titanium polyethylene and non-homogeneous catalytic synthesis of β-amino carbonyl compounds
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Paragraph 0033; 0034; 0035; 0036, (2016/10/08)
The invention discloses a method for synthesizing a beta-amidogen carbonyl compound through poly-aminophenol and titanocene dichloride in a heterogeneous catalysis mode. The beta-amidogen carbonyl compound is obtained by making ketone, aromatic aldehyde and aromatic amine to react at the temperature ranging from 25 DEG C to 50 DEG C at the presence of the titanocene dichloride serving as a catalyst and poly-ortho-aminophenol or poly-m-aminophenol. According to the method, the poly-aminophenol and the titanocene dichloride are added to a reaction system at the same time, a catalytic active species with high activity can be formed in situ, operation is simple, no solvent is added, reaction conditions are mild, the catalyst is low in price, nontoxic, stable in air and water, high in catalytic activity and capable of being repeatedly used, products are prone to separation, and the productivity is high. The method has the advantages that cost is low, environmental friendliness is achieved, and atom economy is high. The method has wide application prospects for the beta-amidogen carbonyl compound.
Synthesis of [beta]-amino ketone compounds through catalysis by bifunctional ionic liquid
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Paragraph 0029; 0030, (2017/05/18)
The invention discloses a synthesis method of [beta]-amino ketone compounds through catalysis by a bifunctional ionic liquid. A key of the technical scheme is that the bifunctional ionic liquid having bifunctional groups of Bronsted acid and Lewis acid is employed as a catalyst while water/ethanol are employed as a reaction medium. Raw materials, including aromatic aldehyde, ketone and aromatic amine, are subjected to a reaction at normal temperature and under normal pressure to obtain a target product. The synthesis method has the advantages of: 1) the raw materials are widely-sourced and the compounds are easy to prepare; 2) the catalyst has bifunctional groups, wherein the Bronsted acid and the Lewis acid in the molecule achieve synergistic catalysis, and the catalyst can be recycled, thereby achieving significant energy-saving and emission-reducing effects; and 3) the synthesis method is carried out with the water/ethanol as the reaction medium, so that the method has safe and stable reactions, is easy to industrially amplify and is an environment-friendly chemical engineering process.
Solvent strategy for unleashing the Lewis acidity of titanocene dichloride for rapid Mannich reactions
Wu, Ya,Wang, Xiu,Luo, Yanlong,Wang, Jing,Jian, Yajun,Sun, Huaming,Zhang, Guofang,Zhang, Weiqiang,Gao, Ziwei
, p. 15298 - 15303 (2016/02/23)
The remarkable activation effect of alcohol solvent on kinetically inert titanocene dichloride was found to promote rapid three-component Mannich reactions. NMR and ESI-MS analyses as well as a control experiment of catalytic active species elucidated that the coordination of MeOH to the titanocene moiety unleashed the Lewis acid [Cp2Ti(OMe)2] and Br?nsted acid HCl, which led to the enhanced catalytic activity of [Cp2TiCl2].
Polyelectrolyte Br?nsted acid catalyzed three-component Mannich reactions accelerated by emulsion
Chen, Xi,Sun, Huaming,Luo, Yanlong,Jian, Yajun,Wu, Ya,Zhang, Weiqiang,Gao, Ziwei
, p. 39343 - 39347 (2016/05/24)
An effective polyelectrolyte Br?nsted acid (polyacrylic acid) catalyzed three-component Mannich reaction accelerated by emulsion has been developed. The results demonstrated that the polyacrylic acid (PAA) provided the best catalytic activity in water because of the formation of emulsions during the reaction. This newly developed simple catalyst could be recycled at least five times without any loss of activity.
Deep Eutectic Solvent as a Recyclable Catalyst for Three-Component Synthesis of β-Amino Carbonyls
Keshavarzipour, Fariba,Tavakol, Hossein
, p. 1062 - 1066 (2015/02/19)
We have reported one-pot, three-component Mannich type reaction of aldehyde, amines and ketone (acetone and acetophenones), catalyzed by deep eutectic solvent (choline chloride/zinc chloride) at room temperature to give β-amino carbonyls in good yields. The catalyst could be recycled at least four times without remarkable decrease in its catalytic activity. The general method is easy, fast and environmental friendly.
Titanocene dichloride and poly(o-aminophenol) as a new heterogeneous cooperative catalysis system for three-component Mannich reaction
Zhu, Xuyang,Chen, Chun,Yu, Binxun,Wu, Ya,Zhang, Guofang,Zhang, Weiqiang,Gao, Ziwei
, p. 4346 - 4349 (2015/09/01)
A new heterogeneous cooperative catalysis system featuring the synergistic effect of an organometallic Lewis acid and a Bronsted acid supporter was developed. The catalysis system successfully catalyzed the direct Mannich reaction of both aromatic and aliphatic ketones in excellent yields. The catalyst can be recycled at least five times and the yield of the Mannich product remains over 90%.
The zeolite ZSM-5-SO3H catalyzed aza-Michael addition of amines and sulfonamides to electron-deficient alkenes under solventfree conditions
Douraki, Saba Mohammadi,Massah, Ahmad Reza
, p. 1346 - 1349 (2015/11/10)
Aza-Micheal addition of aromatic and aliphatic amines and sulfonamides to α,β-unsaturated esters, ketones and nitriles has been developed using the zeolite ZSM-5-SO3H as catalyst under solvent-free conditions.
The zeolite ZSM-5-SO3H catalyzed aza-Michael addition of amines and sulfonamides to electron-deficient alkenes under solvent-free conditions
Douraki, Saba Mohammadi,Massah, Ahmad Reza
, p. 1346 - 1349 (2016/02/26)
Aza-Micheal addition of aromatic and aliphatic amines and sulfonamides to α,β-unsaturated esters, ketones and nitriles has been developed using the zeolite ZSM-5-SO3H as catalyst under solvent-free conditions.
Cooperative catalysis of p-aminophenol and titanocene dichloride in direct Mannich reactions with acetone
Zhu, Xuyang,Chen, Chun,Yu, Binxun,Zhang, Guofang,Zhang, Weiqiang,Gao, Ziwei
, p. 1832 - 1834 (2015/01/16)
A new binary acid system featuring an air stable organometallic precursor, titanocene dichloride and a simple Bronsted acidbase compound, was developed. The new catalyst system allowed for mild and highly efficient direct three-component Mannich reactions of both aryl ketones and alkyl ketones, in particular, acetone and its derivatives with excellent yields. Mechanistic study elucidated the dramatic synergistic effect of the new binary acid system.
