24005-23-0Relevant articles and documents
Phosphonium-stibonium and bis-stibonium cations as pnictogen-bonding catalysts for the transfer hydrogenation of quinolines
Yang, Mengxi,Hirai, Masato,Gabba?, Fran?ois P.
, p. 6685 - 6689 (2019)
Bifunctional Lewis acidic group 15 compounds have emerged as appealing platforms for anion sensing and organocatalysis. As part of our interest in the chemistry of these compounds, we have now compared the catalytic properties of [o-(MePPh2)Cs
Cobalt catalyzed sp3 C-H amination utilizing aryl azides
Villanueva, Omar,Weldy, Nina MacE,Blakey, Simon B.,MacBeth, Cora E.
, p. 6672 - 6675 (2015)
A dinuclear Co(ii) complex supported by a modular, tunable redox-active ligand system is capable of selective C-H amination to form indolines from aryl azides in good yields at low (1 mol%) catalyst loading. The reaction is tolerant of medicinally relevant heterocycles, such as pyridine and indole, and can be used to form 5-, 6-, and 7-membered rings. The synthetic versatility obtained using low loadings of an earth abundant transition metal complex represents a significant advance in catalytic C-H amination technology.
Deciphering a Reaction Network for the Switchable Production of Tetrahydroquinoline or Quinoline with MOF-Supported Pd Tandem Catalysts
Bao, Zongbi,Chen, Jingwen,Huang, Wenyu,Kobayashi, Takeshi,Nie, Renfeng,Qi, Long,Qi, Zhiyuan,Ren, Qilong,Sun, Qi,Yang, Qiwei,Zhang, Biying,Zhang, Zhiguo
, p. 5707 - 5714 (2020)
A mechanistic study of heterogeneous tandem catalytic systems is crucial for understanding and improving catalyst activity and selectivity but remains challenging. Here, we demonstrate that a thorough mechanistic study of a multistep reaction can guide us to the controllable selective synthesis of phenyltetrahydroquinoline or phenylquinoline with easily accessible precursors. The one-pot production can be achieved, catalyzed by a well-defined, bifunctional metal-organic framework-supported Pd nanoparticles, with only water as the side product. Our mechanistic study identifies six transient intermediates and ten transformation steps from the operando magic angle spinning nuclear magnetic resonance study under 27.6 bar H2. In particular, reactive intermediate 2-phenyl-3,4-dihydroquinoline cannot be observed with conventional chromatographic techniques but is found to reach the maximal concentration of 0.11 mol L-1 under the operando condition. The most probable reaction network is further deduced based on the kinetic information of reaction species, obtained from both operando and ex situ reaction studies. This deep understanding of the complex reaction network enables the kinetic control of the conversions of key intermediate, 2-phenyl-3,4-dihydroquinoline, with the addition of a homogeneous co-catalyst, allowing the selective production of tetrahydroquinoline or quinoline on demand. The demonstrated methods in this work open up new avenues toward efficient modulation of reactions with a complex network to achieve desired selectivities.
Thiophostone-derived Bronsted acids in the organocatalyzed transfer hydrogenation of quinolines: Influence of the P-stereogenicity
Ferry, Angelique,Stemper, Jeremy,Marinetti, Angela,Voituriez, Arnaud,Guinchard, Xavier
, p. 188 - 193 (2014)
A new approach to Bronsted acid organocatalysis is described and is based on the use of thiophosphonic acids possessing both a chiral backbone and a chiral phosphorus function. The influence of the phosphorus stereochemistry on the enantioselectivity prov
Liberating N-CNTs Confined Highly Dispersed Co?Nx Sites for Selective Hydrogenation of Quinolines
Gong, Wanbing,Yuan, Qinglin,Chen, Chun,Lv, Yang,Lin, Yue,Liang, Changhao,Wang, Guozhong,Zhang, Haimin,Zhao, Huijun
, (2019)
Selective hydrogenation of quinoline and its derivatives is an important means to produce corresponding 1,2,3,4-tetrahydroquinolines for a wide spectrum of applications. A facile and efficient “laser irradiation in liquid” technique to liberate the inaccessible highly dispersed Co?Nx active sites confined inside N-doped carbon nanotubes is demonstrated. The liberated Co?Nx sites possess generic catalytic activities toward selective hydrogenation of quinoline and its hydroxyl, methyl, and halogen substituted derivatives into corresponding 1,2,3,4-tetrahydroquinolines with almost 100% conversion efficiency and selectivity. This laser irradiation treatment approach should be widely applicable to unlock the catalytic powers of inaccessible catalytic active sites confined by other materials.
Chiral chalcogen bond donors based on the 4,4'-bipyridine scaffold
Weiss, Robin,Aubert, Emmanuel,Peluso, Paola,Cossu, Sergio,Pale, Patrick,Mamane, Victor
, (2019)
Organocatalysis through chalcogen bonding (ChB) is in its infancy, as its proof-of-principle was only reported in 2016. Herein, we report the design and synthesis of new chiral ChB donors, as well as the catalytic activity evaluation of the 5,50-dibromo-2
Tuning porosity and activity of microporous polymer network organocatalysts by co-polymerisation
Schmidt, Johannes,Kundu, Dipti Sankar,Blechert, Siegfried,Thomas, Arne
, p. 3347 - 3349 (2014)
Microporous polymer networks based on binaphthyl phosphoric acids are suitable heterogeneous asymmetric organocatalysts. Herein we show that the porous characteristics of such networks can be fine-tuned by co-polymerisation. This enables us to investigate the influence of the surface area and porosity in microporous networks on their catalytic performance. In this case, the activity of the polymers in an asymmetric hydrogenation reaction is increased by the use of polymers with higher surface areas. The Royal Society of Chemistry 2014.
Catalysis with Chalcogen Bonds
Benz, Sebastian,López-Andarias, Javier,Mareda, Jiri,Sakai, Naomi,Matile, Stefan
, p. 812 - 815 (2017)
Herein, we introduce catalysts that operate with chalcogen bonds. Compared to conventional hydrogen bonds, chalcogen bonds are similar in strength but more directional and hydrophobic, thus ideal for precision catalysis in apolar solvents. For the transfer hydrogenation of quinolines and imines, rate enhancements well beyond a factor of 1000 are obtained with chalcogen bonds. Better activities with deeper σ holes and wider bite angles, chloride inhibition and correlation with computed anion binding energies are consistent with operational chalcogen bonds. Comparable to classics, such as 2,2′-bipyrroles or 2,2′-bipyridines, dithieno[3,2-b;2′,3′-d]thiophenes (DTTs), particularly their diimides, but also wide-angle cyclopentadithiazole-4-ones are identified as privileged motifs to stabilize transition states in the focal point of the σ holes on their two co-facial endocyclic sulfur atoms.
Method for selective catalytic hydrogenation of aromatic heterocyclic compounds in non-hydrogen participation manner
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Paragraph 0025-0029; 0080-0084, (2021/08/19)
The invention discloses a method for selective catalytic hydrogenation of aromatic heterocyclic compounds in a non-hydrogen participation manner. The method comprises the following steps: by taking 1, 5-cyclooctadiene iridium chloride dimer as a catalyst and phenylsilane as a hydrogen source, carrying out stirring reaction under mild conditions without adding a ligand, namely catalytically hydrogenating the aromatic heterocyclic compounds to obtain hydrogenated products of the aromatic heterocyclic compounds. The method has the advantages of low cost, mild reaction conditions, high selectivity and the like, and special equipment such as a high-pressure kettle and the like and high-temperature conditions which are required when hydrogen is used are avoided.
PREPARATION METHOD OF 2-SUBSTITUTED 1,2,3,4-TETRAHYDROQUINOLINE COMPOUND
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Paragraph 0111-0121, (2021/08/05)
2 -substituted quinoline compounds are disclosed. The present invention relates to a 2 -substituted 2 -tetrahydroquinoline compound by hydroconversion of 1, 2, 3, 4 -substituted quinoline compounds using a catalyst composition comprising an isothiuronium salt and a Handoesr. In accordance with the present invention, 2 -substituted 1, 2, 3, 4 -tetrahydroquinoline compounds can be produced in high yield with improved reaction efficiency and reaction rate.
