43008-74-8Relevant articles and documents
Direct conversion of secondary propargyl alcohols into 1,3-di-arylpropanoneviaDBU promoted redox isomerization and palladium assisted chemoselective hydrogenation in a single pot operation
Bera, Mrinal K.,Chandra, Shubhadeep,De, Rimpa,Savarimuthu, S. Antony
, p. 17871 - 17877 (2021/10/12)
Palladium(ii)acetate is found to be an efficient catalyst for the single-step conversion of secondary propargyl alcohols to 1,3-diarylpropanone derivatives under mild basic conditions. The reaction is believed to proceedviaredox isomerisation of secondary propargyl alcohols followed by chemoselective reduction of an enone double bond with formic acid as an adequate hydrogen donor. A large number of 1,3-diarylpropanone derivatives may readily be prepared from a milligram to a multigram scale.
A Proton-Responsive Pyridyl(benzamide)-Functionalized NHC Ligand on Ir Complex for Alkylation of Ketones and Secondary Alcohols
Kaur, Mandeep,U Din Reshi, Noor,Patra, Kamaless,Bhattacherya, Arindom,Kunnikuruvan, Sooraj,Bera, Jitendra K.
supporting information, p. 10737 - 10748 (2021/06/15)
A Cp*Ir(III) complex (1) of a newly designed ligand L1 featuring a proton-responsive pyridyl(benzamide) appended on N-heterocyclic carbene (NHC) has been synthesized. The molecular structure of 1 reveals a dearomatized form of the ligand. The protonation of 1 with HBF4 in tetrahydrofuran gives the corresponding aromatized complex [Cp*Ir(L1H)Cl]BF4 (2). Both compounds are characterized spectroscopically and by X-ray crystallography. The protonation of 1 with acid is examined by 1H NMR and UV-vis spectra. The proton-responsive character of 1 is exploited for catalyzing α-alkylation of ketones and β-alkylation of secondary alcohols using primary alcohols as alkylating agents through hydrogen-borrowing methodology. Compound 1 is an effective catalyst for these reactions and exhibits a superior activity in comparison to a structurally similar iridium complex [Cp*Ir(L2)Cl]PF6 (3) lacking a proton-responsive pendant amide moiety. The catalytic alkylation is characterized by a wide substrate scope, low catalyst and base loadings, and a short reaction time. The catalytic efficacy of 1 is also demonstrated for the syntheses of quinoline and lactone derivatives via acceptorless dehydrogenation, and selective alkylation of two steroids, pregnenolone and testosterone. Detailed mechanistic investigations and DFT calculations substantiate the role of the proton-responsive ligand in the hydrogen-borrowing process.
A nanoscale iron catalyst for heterogeneous direct: N - And C -alkylations of anilines and ketones using alcohols under hydrogen autotransfer conditions
Nallagangula, Madhu,Sujatha, Chandragiri,Bhat, Venugopal T.,Namitharan, Kayambu
supporting information, p. 8490 - 8493 (2019/07/22)
Here, we report a commercially available nanoscale Fe catalyst for heterogeneous direct N- and C-alkylation reactions of anilines and methyl ketones with alcohols. A hydrogen autotransfer mechanism has been found to operate in these reactions by deuterium labelling studies. In addition, dehydrogenative quinoline synthesis has been demonstrated from amino benzyl alcohols and acetophenones.
Nickel-Catalyzed Alkylation of Ketone Enolates: Synthesis of Monoselective Linear Ketones
Das, Jagadish,Vellakkaran, Mari,Banerjee, Debasis
supporting information, p. 769 - 779 (2019/01/24)
Herein we have developed a Ni-catalyzed protocol for the synthesis of linear ketones. Aryl, alkyl, and heteroaryl ketones as well as alcohols yielded the monoselective ketones in up to 90% yield. The catalytic protocol was successfully applied in to a gram-scale synthesis. For a practical utility, applications of a steroid derivative, oleyl alcohol, and naproxen alcohol were employed. Preliminary catalytic investigations involving the isolation of a Ni intermediate and defined Ni-H species as well as a series of deuterium-labeling experiments were performed.
Design and Synthesis of Zirconium-Containing Coordination Polymer Based on Unsymmetric Indolyl Dicarboxylic Acid and Catalytic Application on Borrowing Hydrogen Reaction
Hu, Xinyu,Zhu, Haiyan,Sang, Xinxin,Wang, Dawei
supporting information, p. 4293 - 4300 (2018/10/02)
Catalytic borrowing hydrogen reaction is a very attractive transformation in the field of C-alkylation reaction. In this work, a new Zr (Zirconium)-containing coordination polymer containing unsymmetric indolyl dicarboxylic acid 1-(carboxymethyl)-1H-indole-5-carboxylic acid (H2CIA) was synthesized by the way of a solvothermal synthetic route and characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Nitrogen adsorption-desorption, fourier transform infrared spectroscopy and X-ray photoelectronic spectroscopy (XPS). The coordination polymer Zr-CIA was employed as the catalyst for C-alkylation of acetophenone derivatives in the presence of benzyl alcohol. In addition, Zr-CIA catalyst was also observed to be effective in the reaction of alcohols with alcohols and high yields of alkylation products were achieved. Mechanism investigations were also conducted to better understand the catalysts and transformations. Meanwhile, the Zr-CIA could be reused at least five times without a notable decrease in activity and selectivity. (Figure presented.).
In Water and under Mild Conditions: α-Alkylation of Ketones with Alcohols by Phase-Transfer-Assisted Borrowing Hydrogen Catalysis
Rakers, Lena,Sch?fers, Felix,Glorius, Frank
supporting information, p. 15529 - 15532 (2018/10/09)
Borrowing hydrogen is a powerful and green technique that allows readily available alcohols to be used as alkylating agents and produces water as the only by-product. Nevertheless, harsh conditions such as high temperatures and organic solvents are usually required. Herein, we present a strategy to perform the α-alkylation of ketones in aqueous media at mild temperatures by combining borrowing hydrogen with phase-transfer catalysis. A broad scope of methyl ketones was functionalized with alkyl and benzyl alcohols in moderate to good yields at 40 °C. The protocol was also highly effective at large scale and room temperature.
[Pd]-Catalyzed Intermolecular Coupling and Acid Mediated Intramolecular Cyclodehydration: One-Pot Synthesis of Indenes
Niharika, Pedireddi,Satyanarayana, Gedu
supporting information, p. 971 - 979 (2018/02/22)
An efficient one-pot synthesis of indenes from simple starting materials is presented. This process involves a dual C–C bond formation through an intermolecular Heck coupling reaction followed by acid-mediated intramolecular cyclodehydration. The strategy
Method for synthesizing alpha-alkyl ketone
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Paragraph 0118; 0119; 0120; 0121; 0122, (2017/04/12)
The invention discloses a method for synthesizing alpha-alkyl ketone, and especially includes the following steps of: in a reaction vessel, adding secondary alcohol, a transition metal catalyst, and a solvent tertiary amyl alcohol; and heating and refluxing a reaction mixture in an oil bath for several hours, cooling the mixture to a room temperature; then adding primary alcohol and alkali, heating and refluxing the reaction mixture for several hours, and then obtaining a target compound through column separation. The method for synthesizing the alpha-alkyl ketone starts from the primary alcohol and the secondary alcohol. With the participation of the transition metal catalyst, the alpha-alkyl ketone is generated through a serial secondary alcohol non-acceptor dehydrogenation oxidation reaction/alpha-alkylation reaction of ketone. The reaction shows three obvious advantages that 1) non-toxic alcohols are used as the starting materials; 2) only hydrogen and water are generated in the reaction without environmental hazards; 3) atomic economy is high in the reaction; and 4) only 0.1 equivalents of carbonate is needed for the reaction, and the reaction only takes 3-6 hours. Therefore, the reaction meets the requirements of green chemistry and has broad development prospects.
Isolation and Characterization of Regioisomers of Pyrazole-Based Palladacycles and Their Use in α-Alkylation of Ketones Using Alcohols
Mamidala, Ramesh,Samser, Shaikh,Sharma, Nishant,Lourderaj, Upakarasamy,Venkatasubbaiah, Krishnan
supporting information, p. 3343 - 3351 (2017/09/18)
Regioisomers of 3,5-diphenyl-1-(4-(trifluoromethyl)phenyl)-1H-pyrazole-based palladacycles (1 and 2) were synthesized by the aromatic C-H bond activation of N/3-aryl ring. The application of these regioisomers as catalysts to enable the formation of α-alkylated ketones or quinolines with alcohols using a hydrogen borrowing process is evaluated. Experimental results reveal that palladacycle 2 is superior over palladacycle 1 to catalyze the reaction under similar reaction conditions. The reaction mechanisms for the palladacycles 1 and 2 catalyzed α-alkylation of acetophenone were studied using density functional theoretical (DFT) methods. The DFT studies indicate that palladacycle 2 has an energy barrier lower than that of palladacycle 1 for the alkylation reaction, consistent with the better catalytic activity of palladacycle 2 seen in the experiments. The palladacycle-phosphine system was found to tolerate a wide range of functional groups and serves as an efficient protocol for the synthesis of α-alkylated products under solvent-free conditions. In addition, the synthetic protocol was successfully applied to prepare donepezil, a drug for Alzheimer's disease, from simple starting materials.
Method for synthesizing alpha-alkyl ketone under catalysis of iridium
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Paragraph 0100; 0101; 0102; 0103; 0104, (2017/07/12)
The invention discloses a method for synthesizing alpha-alkyl ketone under catalysis of iridium. The method comprises steps as follows: ketone, an alcohol compound, a iridium complex catalyst, alkali and a solvent, namely, tert-amyl alcohol are added to a reaction container, the reaction mixture is subjected to a reflux reaction in the air and cooled to the room temperature after the reaction ends, a solvent is removed through rotary evaporation, and a target compound is obtained through column separation. A tridentate iridium complex with an N^C^N ligand is used, all that is required is to add 0.2 equivalents of carbonate during the reaction in the air, the reaction takes only 10-12 h, and remarkable advantages are shown. Therefore, the reaction meets the green chemistry requirement, and broad development prospect is realized.
