5681-31-2Relevant academic research and scientific papers
Catalyst for α alkylation of nitriles and uses thereof
-
Paragraph 0060-0063; 0069, (2021/06/22)
The invention discloses a nitrile alpha-alkylation reaction catalyst and application thereof. The nitrile alkylation reaction catalyzed by pyridine-pyridine-imidazoline asymmetric pincerlike rutheniumcompounds has a reaction general formula shown in the specification, and in the general formula, a catalyst is a pyridine-pyridine-imidazoline asymmetric pincerlike ruthenium compound, R1 is aryl, and R2 is aryl or alkyl, wherein aryl is phenyl, p-methylphenyl, p-methoxyphenyl, p-chlorophenyl, thiophene and the like, and alkyl is n-butyl, phenylpropyl and the like. The synthesis method comprisesthe following synthesis steps: adding an asymmetric pincerlike ruthenium compound, an alkali, a nitrile compound and an alcohol into a solvent for reaction, and after the reaction is finished, conducting separating and purifying to obtain a corresponding target product. Alcohol is used as an alkylating reagent, generated water is a unique by-product, the method conforms to the ideas of atom economy and environmental friendliness, and meanwhile, the method has the advantages of use of a catalytic amount of alkali, short reaction time, economy and the like.
α-Alkylation of arylacetonitriles with primary alcohols catalyzed by backbone modified N-heterocyclic carbene iridium(i) complexes
Arslan, Burcu,Gülcemal, Süleyman
, p. 1788 - 1796 (2021/02/16)
A series of backbone-modified N-heterocyclic carbene (NHC) complexes of iridium(i) (1d-f) have been synthesized and characterized. The electronic properties of the NHC ligands have been assessed by comparison of the IR carbonyl stretching frequencies of thein situprepared [IrCl(CO)2(NHC)] complexes in CH2Cl2. These new complexes (1d-f), together with previously prepared1a-c, were applied as catalysts for the α-alkylation of arylacetonitriles with an equimolar amount of primary alcohols or 2-aminobenzyl alcohol. The catalytic activities of these complexes could be controlled by modifying the N-substituents and backbone of the NHC ligands. The NHC-IrIcomplex1fbearing 4-methoxybenzyl substituents on the N-atoms and 4-methoxyphenyl groups at the 4,5-positions of imidazole exhibited the highest catalytic activity in the α-alkylation of arylacetonitriles with primary alcohols. Various α-alkylated nitriles and aminoquinolines were obtained in high yields through a borrowing hydrogen pathway by using 0.1 mol%1fand a catalytic amount of KOH (5 mol%) under an air atmosphere within significantly short reaction times.
Ru(II)-PBTNNXN complex bearing functional 2-(pyridin-2-yl)benzo[d]thiazole ligand catalyzed α-alkylation of nitriles with alcohols
Huang, Shuang,Hong, Xi,Sun, Yong,Cui, He-Zhen,Zhou, Quan,Lin, Yue-Jian,Hou, Xiu-Feng
, (2020/02/13)
Six tridentate NNN ligand precursors derived from 2-(pyridin-2-yl)benzo[d]thiazole(PBT) with different linkers, PBTNNXN (X = NH, NMe, O, S) (1a–1f), have been successfully prepared. The electronic properties of PBTNNXN ligands are well tunable by differing linkers between PBT skeleton and the pyridine ring, and/or by introducing electron-donating/withdrawing groups on the pyridine ring (R = OMe or F). The ligand precursors and representative complexes Ru (PBTNNNHN)Cl2(PPh3) (2a), Ru (PBTNNNMeN)Cl2(PPh3) (2b), and Ru (PBTNNSN)Cl2(PPh3) (2f) have been characterized by NMR spectroscopy, high-resolution mass spectroscopy, and Fourier transform infrared (FT-IR). The molecular structures of 1f, 2a, and 2f have been determined by X-ray diffraction study. The results indicate that PBTNNNHN ligand in the complex presented coplanar with two five-membered chelating rings. It should be noted that 2a featuring a NH group exhibits superior performance compared to those with other linkers (such as NMe, O, or S). A variety of heterocyclic and aromatic nitriles with aromatic and aliphatic alcohols have been explored in α-alkylation for good to excellent yields. Based on kinetic experiments and mechanistic studies, a proposed mechanism was put forward. Ru-H species and benzaldehyde, which was oxidized from benzyl alcohol, were detected in the catalytic cycle.
α-Alkylation of Nitriles with Primary Alcohols by a Well-Defined Molecular Cobalt Catalyst
Paudel, Keshav,Xu, Shi,Ding, Keying
, p. 14980 - 14988 (2020/12/02)
The α-alkylation of nitriles with primary alcohols to selectively synthesize nitriles by a well-defined molecular homogeneous cobalt catalyst is presented. Thirty-two examples with up to 95% yield are reported. Remarkably, this transformation is environmentally friendly and atom economical with water as the only byproduct.
Nickel-catalyzed hydrogen-borrowing strategy: Chemo-selective alkylation of nitriles with alcohols
Banerjee, Debasis,Bera, Atanu,Bera, Sourajit
supporting information, p. 6850 - 6853 (2020/07/04)
The first nickel-catalyzed hydrogen-borrowing alkylation of a series of aryl acetonitriles with a variety of aryl, heteroaryl, allylic and alkyl alcohols releasing water as the by-product (>33 examples, up to 90% yield) is reported.
Copper(i)-catalyzed intermolecular cyanoarylation of alkenes: Convenient access to α-alkylated arylacetonitriles
Chen, Xin-Jie,Gui, Qing-Wen,Yi, Rongnan,Yu, Xianyong,Wu, Zhi-Lin,Huang, Ying,Cao, Zhong,He, Wei-Min
supporting information, p. 5234 - 5237 (2020/07/23)
A novel Cu(i)-catalyzed intermolecular cyanoarylation of alkenes with diaryliodonium salts as a radical arylating reagent and tetra-butylammonium cyanide as an electrophilic cyanating reagent was established. A broad range of α-alkylated arylacetonitriles were efficiently constructed in good to excellent yields under base- and oxidant-free and mild conditions. This journal is
α-Alkylation of Nitriles with Alcohols Catalyzed by NNN′ Pincer Ru(II) Complexes Bearing Bipyridyl Imidazoline Ligands
Zhu, Zhi-Hui,Li, Yigao,Wang, Yan-Bing,Lan, Zhi-Gang,Zhu, Xinju,Hao, Xin-Qi,Song, Mao-Ping
, p. 2156 - 2166 (2019/05/21)
A series of unsymmetrical NNN′ ruthenium(II) complexes supported by a tridentate bipyridyl imidazoline ligand with variable steric hindrance (2a-c; R1 = tBu, iPr, or Bn) and electronic effect (2d-h; R2 = H, CH3, OCH3, Br, or NO2) were prepared. The molecular structures of ligands 1f and 1g, and Ru complex 2a were further determined by X-ray single-crystal diffraction. The catalytic activity of these eight complexes for α-alkylation of nitriles with alcohols was evaluated, which could be controlled by the substituents on the imidazoline moiety. Ru complex 2h bearing a strong electron-withdrawing group (R2 = NO2) demonstrated the highest catalytic activity, with alkylated nitriles achieved in up to 97% yield.
Manganese Catalyzed α-Alkylation of Nitriles with Primary Alcohols
Jana, Akash,Reddy, C. Bal,Maji, Biplab
, p. 9226 - 9231 (2018/09/21)
The manganese(I) complex bearing a bidentate hydrazone ligand efficiently catalyzes the α-alkylations of nitrile using primary alcohols as alkylating agents. α-Functionalized nitriles were selectively obtained in good to excellent yields. The reaction is environmentally benign, producing water as the sole byproduct. Both benzylic and aliphatic alcohols could be used and functional groups were tolerated.
Guidelines for the use of proton donors in SmI2 reactions: Reduction of α-cyanostilbene
Amiel-Levy, Mazal,Hoz, Shmaryahu
supporting information; experimental part, p. 8280 - 8284 (2009/12/02)
The reduction of a series of α-cyanostilbenes with SmI2was studied in THF in the presence of various proton donors. No reactio n occurred in the presence of the alcohols TFE, i-PrOH and t-BuOH. In the presence of MeOH, water and ethylene glycol the reactions occurred; however in the presence of water and ethylene glycol they were too fast for kinetic determinations (τ1/2 2 and first order in the substrate.The order in MeOH varies as a function of its concentration and the plo t of log k vs log [MeOH] is sigmoidal. Comparison of the kinetic isotopeeffect and the incorporation isotope effect suggests that, counterintui tively, protonation of the radical anion takes place on the carbon β to the cyano group. It is concluded that proton donors that form complexes with SmI2 expand the range of substrates that can be reduced by SmI2. This is due to their proximity to the radical anion as it is formed. This short-lived radical anion cannot be efficiently trapped by a proton donor from the bulk medium. A protocol is herein suggested as to when proton donors which complex to SmI2, e.g. MeOH, water and ethyleneglycol should be used, and when it is recommended to use noncomplexing proton donors, e.g. TFE, i-PrOH and t-BuOH, to induce reaction.
Transfer hydrogenation of activated C=C bonds catalyzed by ruthenium amido complexes: Reaction scope, limitation, and enantioselectivity
Xue, Dong,Chen, Ying-Chun,Cui, Xin,Wang, Qi-Wei,Zhu, Jin,Deng, Jin-Gen
, p. 3584 - 3591 (2007/10/03)
(Chemical Equation Presented) It was found that the chemoselectivity could be completely switched from C=O to C=C bonds in the transfer hydrogenation of activated α,β-unsaturated ketones catalyzed by diamine-ruthenium complex. Moreover, this addition via metal hydride had been applied to the reduction of various activated olefins. The electron-withdrawing ability of functional groups substituted on C=C bonds at the α- or β-position had strong influence on the reactivity. In addition, a wide variety of chiral diamine-Ru(II)-(arene) systems was investigated to explore the asymmetric transfer hydrogenation of prochiral α,α-dicyanoolefins. Two parameters had been systematically studied, (i) the structure of the N-sulfonylated chiral diamine ligands, in which several chiral diamines substituted on the benzene ring of DPEN were first reported, and (ii) the structure of the metal precursors, and high enantioselectivitiy (up to 89% ee) at the β-carbon was obtained.
