95465-72-8Relevant academic research and scientific papers
BTP-Rh@g-C3N4 as an efficient recyclable catalyst for dehydrogenation and borrowing hydrogen reactions
Luo, Lan,Liu, Hongqiang,Zeng, Wei,Hu, Wenkang,Wang, Dawei
, (2021/11/16)
Highly active catalysts play an important role in modern catalysis. A novel and efficient ligand benzotriazole-pyrimidine (BTP) and the corresponding rhodium composite on C3N4 were successfully synthesized. The resulting rhodium composite was fully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), thermogravimetric analysis (TGA), and x-ray photoelectron spectroscopy (XPS). The obtained composite exhibited good catalytic activity and good recovery performance in the synthesis of quinoxaline from 2-aminobenzyl alcohol and benzonitrile, and more than 20 quinoxalines were obtained in good yields. Additionally, it also showed that rhodium composite could achieved good catalytic performance in the synthesis of functionalized ketone through borrowing hydrogen strategy.
Complementary Photocatalytic Toolbox: Control of Intramolecular endo-versus exo-trig Cyclizations of α-Phenyl Olefins to Oxaheterocyclic Products
Belov, Arina,Steuernagel, Desirée,Wagenknecht, Hans-Achim,Weick, Fabian
, (2022/03/03)
The regioselectivity of the intramolecular cyclization of bifunctional α-phenyl alkenes can be controlled simply by the choice of the organic chromophore as the photocatalyst. The central photoredox catalytic reaction in both cases is a nucleophilic addition of the hydroxyl function to the olefin function of the substrates. N,N-(4-Diisobutylaminophenyl) phenothiazine catalyzes exo-trig cyclizations, whereas 1,7-dicyanoperylene-3,4,9,10-tetracarboxylic acid bisimides catalyze endo-trig additions to products with anti-Markovnikov regioselectivity. We preliminarily report the photoredox catalytic conversions of 11 representative substrates into 20 oxaheterocycles in order to demonstrate the similarity, but also the complementarity, of these two variants in this photoredox catalytic toolbox.
Nickel-Catalyzed Selective Synthesis of α-Alkylated Ketones via Dehydrogenative Cross-Coupling of Primary and Secondary Alcohols
Bains, Amreen K,Biswas, Ayanangshu,Adhikari, Debashis
supporting information, p. 47 - 52 (2021/10/14)
Herein, we describe an isolable, air-stable, homogeneous, nickel catalyst that performs dehydrogenative cross-coupling reaction between secondary and primary alcohols to result α-alkylated ketone products selectively. The sequence of steps involve in this one-pot reaction is dehydrogenation of both alcohols, condensation between the ketone and the aldehyde, and hydrogenation of the in situ-generated α,β-unsaturated ketone. Preliminary mechanistic investigation hints a radical mechanism following borrowing hydrogen reaction. (Figure presented.).
Unveiling the catalytic nature of palladium-N-heterocyclic carbene catalysts in the α-alkylation of ketones with primary alcohols
?etinkaya, Bekir,Ero?lu, Zafer,Gülcemal, Süleyman,Metin, ?nder,Ovezova, Mamajan
supporting information, p. 10896 - 10908 (2021/08/17)
We report herein the synthesis of four new Pd-PEPPSI complexes with backbone-modified N-heterocyclic carbene (NHC) ligands and their application as catalysts in the α-alkylation of ketones with primary alcohols using a borrowing hydrogen process and tandem Suzuki-Miyaura coupling/α-alkylation reactions. Among the synthesized Pd-PEPPSI complexes, complex2chaving 4-methoxyphenyl groups at the 4,5-positions and 4-methoxybenzyl substituents on the N-atoms of imidazole exhibited the highest catalytic activity in the α-alkylation of ketones with primary alcohols (18 examples) with yields reaching up to 95%. Additionally, complex2cwas demonstrated to be an effective catalyst for the tandem Suzuki-Miyaura-coupling/α-alkylation of ketones to give biaryl ketones with high yields. The heterogeneous nature of the present catalytic system was verified by mercury poisoning and hot filtration experiments. Moreover, the formation of NHC-stabilized Pd(0) nanoparticles during the α-alkylation reactions was identified by advanced analytical techniques.
Synthesis of α-Alkylated Ketones via Selective Epoxide Opening/Alkylation Reactions with Primary Alcohols
Gen?, Serta?,Gülcemal, Süleyman,Günnaz, Salih,?etinkaya, Bekir,Gülcemal, Derya
supporting information, p. 5229 - 5234 (2021/07/19)
A new method for converting terminal epoxides and primary alcohols into α-alkylated ketones under borrowing hydrogen conditions is reported. The procedure involves a one-pot epoxide ring opening and alkylation via primary alcohols in the presence of an N-heterocyclic carbene iridium(I) catalyst, under aerobic conditions, with water as the side product.
Iridium Complexes as Efficient Catalysts for Construction of α-Substituted Ketones via Hydrogen Borrowing of Alcohols in Water
Luo, Nianhua,Zhong, Yuhong,Wen, Huiling,Shui, Hongling,Luo, Renshi
, p. 1355 - 1364 (2021/03/03)
Ketones are of great importance in synthesis, biology, and pharmaceuticals. This paper reports an iridium complexes-catalyzed cross-coupling of alcohols via hydrogen borrowing, affording a series of α-alkylated ketones in high yield (86 %–95 %) and chemoselectivities (>99 : 1). This methodology has the advantages of low catalyst loading (0.1 mol%) and environmentally benign water as the solvent. Studies have shown the amount of base has a great impact on chemoselectivities. Meanwhile, deuteration experiments show water plays an important role in accelerating the reduction of the unsaturated ketones intermediates. Remarkably, a gram-scale experiment demonstrates this methodology of iridium-catalyzed cross-coupling of alcohols has potential application in the practical synthesis of α-alkylated ketones.
Ir(NHC)-Catalyzed Synthesis of β-Alkylated Alcohols via Borrowing Hydrogen Strategy: Influence of Bimetallic Structure
Sung, Kihyuk,Lee, Mi-hyun,Cheong, Yeon-Joo,Kim, Yu Kwon,Yu, Sungju,Jang, Hye-Young
supporting information, p. 3090 - 3097 (2021/05/10)
Multi N-heterocyclic carbene(NHC)-modified iridium catalysts were employed in the β-alkylation of alcohols; dimerization of primary alcohols (Guerbet reaction), cross-coupling of secondary and primary alcohols, and intramolecular cyclization of alcohols. Mechanistic studies of Guerbet reaction, including kinetic experiments, mass analysis, and density functional theory (DFT) calculation, were employed to explain the fast reaction promoted by bimetallic catalysts, and the dramatic reactivity increase of monometallic catalysts at the late stage of the reaction. (Figure presented.).
Synthesis and catalytic applications of Ru and Ir complexes containing N,O-chelating ligand
Pakyapan, Bilge,Kavukcu, Serdar Bat?kan,?ahin, Zarife Sibel,Türkmen, Hayati
, (2020/09/01)
A series of monometallic complexes (Ru1–3, Ir1–3) which have N,O-chelating ligand (pyrazine-2-carboxylate (1), pyridine-2-carboxylate (2), quinoline carboxylate(3) and bimetallic complexes (Ru4,5, Ir4,5) bridged by pyrazine-2,3- dicarboxylate (4) and imidazole-4,5-dicarboxylate(5) were synthesized and characterized by 1H-, 13C NMR, FT-IR, and elemental analysis. The crystal structure of Ir2 was determined by X-ray crystallography. The complexes (Ru1–5, Ir1–5) were applied to investigate the electronic and steric effect of ligand in their catalytic activities in transfer hydrogenation and alpha(α)-alkylation reaction of ketones with alcohols. The activities of iridium complexes (Ir1–5) were much more efficient than ruthenium complexes (Ru1–5). The highest activity for both reactions was observed for the complex (Ir2) with pyridine-2-carboxylate. The Ir hydride species was monitored for both reactions.
C-C coupling formation using nitron complexes
Sevim, Mehmet,Kavukcu, Serdar Batikan,Kinal, Arma?an,?ahin, Onur,Türkmen, Hayati
supporting information, p. 16903 - 16915 (2020/12/18)
A series of RuII (1), RhIII (2), IrIII (3, 4), IrI (5) and PdII (6-9) complexes of the 'instant carbene' nitron were prepared and characterized by 1H- and 13C-NMR, FT-IR and elemental analysis. The molecular structures of complexes 1-4 and 6 were determined by X-ray diffraction studies. The catalytic activity of the complexes (1-9) was evaluated in alpha(α)-alkylation reactions of ketones with alcohol via the borrowing hydrogen strategy under mild conditions. These complexes were able to perform this catalytic transformation in a short time with low catalyst and base amounts under an air atmosphere. Also, the PdII-nitron complexes (6-9) were applied in the Suzuki-Miyaura C-C coupling reaction and these complexes successfully initiated this reaction in a short time (30 minutes) using the H2O/2-propanol (1.5?:?0.5) solvent system. The DFT calculations revealed that the Pd0/II/0 pathway was more preferable for the mechanism
Synthesis and Structures of Arene Ruthenium (II)–NHC Complexes: Efficient Catalytic α-alkylation of ketones via Hydrogen Auto Transfer Reaction
Balamurugan, Gunasekaran,Balaji, Sundarraman,Ramesh, Rengan,Bhuvanesh, Nattamai S.P.
, (2018/11/25)
A panel of six new arene Ru (II)-NHC complexes 2a-f, (NHC?=?1,3-diethyl-(5,6-dimethyl)benzimidazolin-2-ylidene 1a, 1,3-dicyclohexylmethyl-(5,6-dimethyl)benzimidazolin-2-ylidene 1b and 1,3-dibenzyl-(5,6-dimethyl)benzimidazolin-2-ylidene 1c) were synthesized from the transmetallation reaction of Ag-NHC with [(η6-arene)RuCl2]2 and characterized. The ruthenium (II)-NHC complexes 2a-f were developed as effective catalysts for α-alkylation of ketones and synthesis of bioactive quinoline using primary/amino alcohols as coupling partners respectively. The reactions were performed with 0.5?mol% catalyst load in 8?h under aerobic condition and the maximum yield was up to 96%. Besides, the different alkyl wingtips on NHC and arene moieties were studied to differentiate the catalytic robustness of the complexes in the transformations.
