46230-01-7Relevant academic research and scientific papers
Furfural and 5-(hydroxymethyl)furfural valorization using homogeneous Ni(0) and Ni(II) catalysts by transfer hydrogenation
Arévalo, Alma,García, Juventino J.,Jurado-Vázquez, Tamara
supporting information, (2021/11/27)
The complex [dippeNi(COD)] (dippe =1,2-bis(diisopropyl phosphino)ethane) was used as a catalytic precursor in furfural (FF) and 5-(hydroxymethyl)furfural (HMF) valorization, along with formic acid as hydrogen transfer agent, to produce the corresponding a
Ru(II)-NHC catalysed N-Alkylation of amines with alcohols under solvent-free conditions
Karaca, Emine ?zge,Dehimat, Zieneb Imene,Ya?ar, Sedat,Gürbüz, Nevin,Tebbani, Dahmane,?etinkaya, Bekir,?zdemir, ?smail
, (2021/04/02)
The reaction of [RuCl2(p-cymene)]2 with in situ prepared Ag-N-heterocyclic carbene (NHC) complexes yields a series of [RuCl2(p-cymene)(NHC)] complexes (2). All of the complexes have been characterised by elemental analysis, and 1H NMR and 13C NMR spectroscopies. These complexes have been tested for the N-alkylation of aromatic amines with arylmethyl alcohols under neat conditions in the presence of KOtBu at 120 °C. Compounds (2) are stable and have high catalytic/selective activity for the N-alkylation reactions of primary amines to afford secondary amines.
Half-sandwich Ru(ii) arene complexes bearing benzimidazole ligands for theN-alkylation reaction of aniline with alcohols in a solvent-free medium
?i?ek, Metin,Gürbüz, Nevin,?zdemir, Nam?k,?zdemir, ?smail,?spir, Esin
, p. 11075 - 11085 (2021/07/02)
In this article, the directN-alkylation reactions of amines with alcohol derivatives using the borrowing hydrogen methodology have been investigated. For this purpose, a new series of half-sandwich ruthenium(ii) complexes bearing N-coordinated benzimidazole complexes have been synthesized and fully characterized by FT-IR,1H NMR and13C NMR spectroscopies. Additionally, the structures of the complexes2a-2ehave been characterized by X-ray crystallography. All new complexes were investigated for their catalytic activities in the alkylation reaction of amines with alcohol derivatives. It was found that alkylation reactions in a solvent-free medium are efficient and selective.
Active ruthenium(II)-NHC complexes for alkylation of amines with alcohols using solvent-free conditions
Yi?it, Beyhan,?zge Karaca, Emine,Yi?it, Murat,Gürbüz, Nevin,Arslan, Hakan,?zdemir, ?smail
, (2019/11/26)
A series of new ruthenium(II) complexes bearing N-heterocyclic carbene ligands with benzylic groups were prepared by transmetallation reactions between silver(I) N-heterocyclic carbene complexes and [RuCl2(p-cymene)]2. All of the obtained complexes were characterized by FT-IR, 1H NMR and 13C NMR spectroscopy, and the molecular structure of compound 3c was also determined by X-ray crystallography. These ruthenium complexes were tested for the alkylation of aromatic amines with a wide range of primary alcohols under solvent-free conditions using the hydrogen borrowing strategy. All of the compounds tested here showed excellent catalytic activity for these reactions and N-monoalkylated products were obtained selectively using 2.5 mol% of the ruthenium complexes.
First used of Alkylbenzimidazole-Cobalt(II) complexes as a catalyst for the N-Alkylation of amines with alcohols under solvent-free medium
?zdemir, ?smail,?zdemir, Nam?k,?ahin, Neslihan,Gürbüz, Nevin,Y?ld?r?m, ?lkay
, (2020/04/28)
In this study, alkylbenzimidazole-cobalt(II)-catalyzed direct N-alkylation reactions of amines with alcohols derivatives have been investigated under solvent-free medium. For this purpose, a series of cobalt(II) complexes bearing N-alkylbenzimidazole complexes have been synthesized and novel complexes fully characterized by elemental analysis, FT-IR, 1H NMR and, 13C{1H} NMR spectroscopies. Also, the structure of the complex 2a has been confirmed by X-ray crystallography. Generally, the N-alkylating reaction is usually performed in toluene with various metal complexes including cobalt. In this catalytic study of complexes, 2a-c has carried out in without solvent and alcohol acted both as solvent and reactant. Conversion and selectivity of amine products according to imine products for alkylation reactions have been seen high yield in medium solvent-free relative to in toluene.
Novel N-Alkylbenzimidazole-Ruthenium (II) complexes: Synthesis and catalytic activity of N-alkylating reaction under solvent-free medium
?ahin, Neslihan,?zdemir, Nam?k,Gürbüz, Nevin,?zdemir, ?smail
, (2019/01/04)
In this article, direct N-alkylation reactions of amines with alcohols derivatives have been investigated. For this purpose, a new series ruthenium (II) complexes bearing N-coordinated benzimidazole complexes with have been synthesized and fully characterized by elemental analysis, FT-IR, 1H NMR and, 13C NMR spectroscopies. Additionally, the structures of the complexes 2b and 2c have been confirmed by X-ray crystallography. Although the N-alkylating reaction is usually performed in toluene, the catalytic study of complexes 2a-d has carried out no additional solvent and alcohol acted both as solvent and reactant of alkylating by using a little excess of alcohols. Surprisingly, conversion and selectivity of amine product for alkylation reaction have been seen high in medium solvent-free relative to in toluene.
Benzimidazolium sulfonate ligand precursors and application in ruthenium-catalyzed aromatic amine alkylation with alcohols
Kaloglu, Nazan,?zdemir, Ismail,Gürbüz, Nevin,Achard, Mathieu,Bruneau, Christian
, p. 33 - 38 (2015/11/17)
New benzimidazolium sulfonate salts have been prepared and fully characterized. They have been associated in situ with [RuCl2(p-cymene)]2 to generate efficient catalytic systems operating at 120 °C under neat conditions in the presence of potassium tert-butylate for selective N-alkylation of primary aromatic amines into secondary amines.
Synchronizing steric and electronic effects in {RuII(NNNN,P)} complexes: The catalytic dehydrative alkylation of anilines by using alcohols as a case study
Weickmann, Daniel,Frey, Wolfgang,Plietker, Bernd
supporting information, p. 2741 - 2748 (2013/03/14)
A series of new hexacoordinated {RuII(NNNN,P)} complexes was prepared from [RuCl2(R3P)3]. Their structure was determined by X-ray crystallography. The catalytic potential of this new class of complexes was tested in the alkylation of aniline with benzyl alcohol. In this test reaction, the influence of the counteranion plus electronic influences at the tetradentate ligand and the phosphine ligand were examined. The electrochemistry of all complexes was studied by cyclic voltammetry. Depending on the substituent at the ligand backbone, the complexes showed a different behavior. For all N-benzyl substituted complexes, reversible Ru II/III redox potentials were observed, whereas the N-methyl substituted complex possessed an irreversible oxidation event at small scan rates. Furthermore, the electronic influence of different substituents at the ligand scaffold and at the phosphine on the RuII/III redox potential was investigated. The measured E0 values were correlated to the theoretically determined HOMO energies of the complexes. In addition, these HOMO energies correlated well with the reactivity of the single complexes in the alkylation of aniline with benzyl alcohol. The exact balance of redox potential and reactivity appears to be crucial for synchronizing the multiple hydrogen-transfer events. The optimized catalyst structure was applied in a screening on scope and limitation in the catalytic dehydrative alkylation of anilines by using alcohols.
Selective alkylation of (Hetero)aromatic amines with alcohols catalyzed by a ruthenium pincer complex
Agrawal, Santosh,Lenormand, Maud,Martin-Matute, Belen
supporting information; experimental part, p. 1456 - 1459 (2012/05/04)
A readily available pincer ruthenium(II) complex catalyzes the selective monoalkylation of (hetero)aromatic amines with a wide range of primary alcohols (including pyridine-, furan-, and thiophene-substituted alcohols) with high efficiency when used in low catalyst loadings (1 mol %). Tertiary amine formation via polyalkylation does not occur, making this ruthenium system an excellent catalyst for the synthesis of sec-amines.
An efficient method for the selective iridium-catalyzed monoalkylation of (hetero)aromatic amines with primary alcohols
Blank, Benoit,Madalska, Martyna,Kempe, Rhett
supporting information; experimental part, p. 749 - 758 (2009/04/10)
An efficient multi-gram scale synthesis protocol of a variety of P,N ligands is described. The synthesis is achieved in a two-step reaction. First, the amine is deprotonated and subsequently the chlorophosphine is added to yield the corresponding P,N ligand. Deprotonation of the amine is normally achieved with n-BuLi at low temperature, but for the preparation of ligands with a 2,2′-dipyridylamino backbone and phosphines with a high steric demand KH has to be employed in combination with reaction temperatures of 110°C for the salt metathesis step. The reaction of two equivalents of a selected P,N ligand with one equivalent of the iridium complex [IrCl(cod)]2 (cod=1,5-cyclooctadiene) affords P,N ligand-coordinated iridium complexes in quantitative yield. X-Ray single crystal structure analysis of one of these complexes reveals a monomeric five-coordinated structure in the solid state. The iridium complexes were used to form catalysts for the N-alkylation of aromatic amines with alcohols. The catalyst system was optimized by studying 8 different P,N ligands, 9 different solvents and 14 different bases. Systematic variation of the substrate to base and the amine to alcohol ratios as well as the catalyst loading led to optimized catalytic reaction conditions. The substrate scope of the developed catalytic protocol was shown by synthesizing 20 different amines of which 12 could be obtained in isolated yields higher than 90%. A new efficient catalyst system for the selective monoalkylation of primary aromatic and heteroaromatic amines with primary aromatic, heteroaromatic as well as aliphatic alcohols has been established. The reaction proceeds with rather moderate catalyst loadings.
