- Designed pincer ligand supported Co(ii)-based catalysts for dehydrogenative activation of alcohols: Studies onN-alkylation of amines, α-alkylation of ketones and synthesis of quinolines
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Base-metal catalystsCo1,Co2andCo3were synthesized from designed pincer ligandsL1,L2andL3having NNN donor atoms respectively.Co1,Co2andCo3were characterized by IR, UV-Vis. and ESI-MS spectroscopic studies. Single crystal X-ray diffraction studies were investigated to authenticate the molecular structures ofCo1andCo3. CatalystsCo1,Co2andCo3were utilized to study the dehydrogenative activation of alcohols forN-alkylation of amines, α-alkylation of ketones and synthesis of quinolines. Under optimized reaction conditions, a broad range of substrates including alcohols, anilines and ketones were exploited. A series of control experiments forN-alkylation of amines, α-alkylation of ketones and synthesis of quinolines were examined to understand the reaction pathway. ESI-MS spectral studies were investigated to characterize cobalt-alkoxide and cobalt-hydride intermediates. Reduction of styrene by evolved hydrogen gas during the reaction was investigated to authenticate the dehydrogenative nature of the catalysts. Probable reaction pathways were proposed forN-alkylation of amines, α-alkylation of ketones and synthesis of quinolines on the basis of control experiments and detection of reaction intermediates.
- Singh, Anshu,Maji, Ankur,Joshi, Mayank,Choudhury, Angshuman R.,Ghosh, Kaushik
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p. 8567 - 8587
(2021/06/30)
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- Cu(I) mediated hydrogen borrowing strategy for the α-alkylation of aryl ketones with aryl alcohols
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Abstract: New triazolium Schiff bases (TSBs) were synthesised via a simple and high throughput process. The new salts were successfully characterised. When reacted with Cu(CH3CN)4PF6, the TSB salts formed mononuclear triazole Schiff base copper(I) complexes and dinuclear complexes that were also characterised. The?copper complexes were generated in situ (mixtures of TSB salts with Cu(CH3CN)4PF6) and applied as homogeneous catalysts for the C–C coupling of a variety of aryl ketones with aryl alcohols, from which?significant reactivity was observed. Reaction conditions were optimised, and the results indicate that the catalyst systems are very robust. A catalyst concentration of 10?mol% efficiently and selectively catalysed the α-alkylation of methyl phenyl ketone and its derivatives to afford up to 94% yield of 1,3-diphenylpropan-1-one and its analogues. The process is adaptable with analogues of acetophenone and benzyl alcohol bearing various regulating substituents tolerated. Graphic abstract: [Figure not available: see fulltext.].
- Lawal, Nasir S.,Ibrahim, Halliru,Bala, Muhammad D.
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p. 275 - 285
(2021/02/09)
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- Efficient Organoruthenium Catalysts for α-Alkylation of Ketones and Amide with Alcohols: Synthesis of Quinolines via Hydrogen Borrowing Strategy and their Mechanistic Studies
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A new family of phosphine free organometallic ruthenium(II) catalysts (Ru1–Ru4) supported by bidentate NN Schiff base ligands (L1–L4 where L1=N,N-dimethyl-4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazineylidene)methyl) aniline, L2=N,N-diethyl-4-((2-phenyl-2-(pyridin-2-ylmethyl)hydrazineylidene)methyl)aniline, L3=N,N-dimethyl-4-((2-phenyl-2-(pyridin-2-yl)hydrazineylidene)methyl)- aniline and L4=N,N-diethyl-4-((2-phenyl-2-(pyridin-2-yl)hydrazineylidene)methyl) aniline) was prepared and characterized. These half-sandwich complexes acted as catalysts for C?C bond formation and exhibited excellent performance in the dehydrogenative coupling of ketones and amides. In the synthesis of C–C bonds, alcohols were utilized as the alkylating agent. A broad range of substrates, including sterically hindered ketones and alcohols, were well tolerated under the optimized conditions (TON up to 47000 and TOF up to 11750 h?1). This ruthenium (II) catalysts were also active towards the dehydrogenative cyclization of o-amino benzyl alcohol for the formation of quinolines derivatives. Various polysubstituted quinolines were synthesized in moderate to excellent yields (TON up to 71000 and TOF up to 11830 h?1). Control experiments were carried out and the ruthenium hydride intermediate was characterized to support the reaction mechanism and a probable reaction pathway of dehydrogenative coupling for the C?C bond formation has been proposed.
- Maji, Ankur,Singh, Anshu,Singh, Neetu,Ghosh, Kaushik
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p. 3108 - 3125
(2020/05/18)
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- Ligand-tuned cobalt-containing coordination polymers and applications in water
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Ligands play a key role in modern catalysis research and occasionally determine whether a reaction will take place under specific conditions, such as in water. In this experiment, ligands containing an indole-based diacid moiety were employed to prepare the corresponding cobalt coordination polymer material (Co-CIA) and porous oval polymer material (Co-NCIA). Interestingly, it was observed that Co-CIA could promote the alkylation of ketones with alcohols and alcohols with alcohols, while Co-NCIA was effective for the synthesis of 1-benzyl-2-aryl-1H-benzo[d]imidazoles from various phenylenediamine and benzyl alcohols through borrowing hydrogen and dehydrogenation strategies. Other mechanism explorations, such as deuterium labeling experiments and a kinetics study, were conducted to better understand Co-CIA and Co-NCIA systems and the related transformations. Our studies provided an efficient method for the development of highly active cobalt coordination polymer materials with excellent recovery performance for dehydrogenation and borrowing hydrogen reactions under water and base-free conditions.
- Tao, Rong,Yang, Yike,Zhu, Haiyan,Hu, Xinyu,Wang, Dawei
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supporting information
p. 8452 - 8461
(2020/12/29)
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- Preparation method of novel aromatic ketone compound
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The invention discloses a preparation method of a novel aromatic ketone compound. According to the preparation method, an aromatic carboxylic acid compound and an aromatic olefin compound are used asreaction raw materials, triphenylphosphine is taken as a deoxidizing reagent, Methylenene blue is taken as a photocatalyst, stirring and reacting are carried out at room temperature in an N,N-dimethylacetamide solvent under the irradiation of a white light lamp in a nitrogen atmosphere and under the condition of taking 2,4,6-trimethylpyridine as an alkali, thereby obtaining a target product, namely the aromatic ketone compound. The method has the advantages of mild reaction conditions, simplicity in operation, low cost, convenience in purification, environmental friendliness and the like.
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Paragraph 0071-0072
(2020/12/08)
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- Utility of Organoboron Reagents in Arylation of Cyclopropanols via Chelated Pd(II) Catalysis: Chemoselective Access to β-Aryl Ketones
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Organoborane reagents were investigated as coupling partners to cyclopropanol-derived β-ketone enolates in the presence of a chelated Pd(II) catalyst. Efficient coupling of a range of electronically and sterically diverse cyclopropanols and aryl/alkenyl boronic derivatives (39 examples, 65-94% yield) could be achieved with the generation of synthetically important β-aryl ketone intermediates in a chemoselective fashion. This reactivity paradigm, which broadens the scope of aryl donor partners to homoenolates, allows open-flask conditions, water as a cosolvent, and preparation of halogen-bearing β-aryl ketones that are distinct from previous methods. This chelated Pd(II) catalysis appears to be different from the Pd(0) pathway, as evident from deuterium scrambling studies that could reveal differentiating protonolysis of an α-keto carbopalladium complex in the terminal step.
- Ilangovan, Andivelu,Ramar, Thangeswaran,Subbaiah, Murugaiah A. M.
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- Design and Synthesis of Zirconium-Containing Coordination Polymer Based on Unsymmetric Indolyl Dicarboxylic Acid and Catalytic Application on Borrowing Hydrogen Reaction
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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.).
- Hu, Xinyu,Zhu, Haiyan,Sang, Xinxin,Wang, Dawei
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supporting information
p. 4293 - 4300
(2018/10/02)
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- BINAP-copper supported by hydrotalcite as an efficient catalyst for the borrowing hydrogen reaction and dehydrogenation cyclization under water or solvent-free conditions
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A BINAP-Cu system supported by hydrotalcite has been developed and proved to be a highly efficient catalyst for the atom-efficient and green borrowing hydrogen reaction and dehydrogenative cyclization. This BINAP-Cu complex supported by hydrotalcite is highly air-stable and can be recycled at least five times under solvent-free conditions. Notably, 1-benzyl-2-aryl-1H-benzo[d]imidazole derivatives could be synthesized from alcohols in only one step with water as the solvent for the first time. This provided a much greener and efficient catalytic method towards the synthesis of functionalized amines, ketones and 1-benzyl-2-aryl-1H-benzo[d]imidazole derivatives with high yields under water or solvent-free conditions.
- Xu, Zhaojun,Yu, Xiaoli,Sang, Xinxin,Wang, Dawei
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supporting information
p. 2571 - 2577
(2018/06/11)
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- Method for preparing substituted ketone compound through oxidization, dehydration and alkylation of secondary alcohol
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The invention discloses a method for preparing a substituted ketone compound through oxidization, dehydration and alkylation of secondary alcohol, and by means of the green synthetic method, substituted ketones are prepared from primary alcohol and the secondary alcohol through a dehydration C-alkylation-oxidization cascade reaction with the existence of alkali but without a transitional metal catalyst. According to the method, the alcohols which are low in price, easy to obtain, wide in source, stable and low in toxicity are used as alkylation reagent, common base metal inorganic base is used as an additive, methylbenzene is used as solvent, air is economical and safe oxidant, and the corresponding substituted ketone compound with secondary alcohol beta alkylated is directly synthesized through the dehydration C-alkylation-oxidization cascade reaction. The reaction method and condition are simple, no transitional metal catalyst is need, no inert gas protection is needed, the method is easy to operate, the by-product is water, compared with a precious metal catalyst, the inorganic base which is used is low in price and easy to obtain and can be removed conveniently through washing, and no heavy metal residue exists in the final product. Therefore, the method is wide in application scope and has certain research and industrial application prospect.
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Paragraph 0076-0079
(2017/02/24)
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- Catalyst-free dehydrative α-alkylation of ketones with alcohols: Green and selective autocatalyzed synthesis of alcohols and ketones
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Direct dehydrative α-alkylation reactions of ketones with alcohols are now realized under simple, practical, and green conditions without using external catalysts. These catalyst-free autocatalyzed alkylation methods can efficiently afford useful alkylated ketone or alcohol products in a one-pot manner and on a large scale by Ci£C bond formation of the in situ generated intermediates with subsequent controllable and selective Meerwein-Pondorf-Verley-Oppenauer-type redox processes. Plain and simple: The title reaction has been realized under simple and practical conditions without using external catalysts, and can afford alkylated ketone or alcohol products in a one-pot manner and on a large scale. The reaction proceeds by Ci£C bond formation of the in situ generated intermediates with subsequent controllable and selective Meerwein-Pondorf-Verley-Oppenauer-type redox processes. Copyright
- Xu, Qing,Chen, Jianhui,Tian, Haiwen,Yuan, Xueqin,Li, Shuangyan,Zhou, Chongkuan,Liu, Jianping
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p. 225 - 229
(2014/01/17)
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- A novel transition metal-free conjugate reduction of α,β-unsaturated ketones with tosylhydrazine as a hydrogen source
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A novel and efficient method has been developed for the chemoselective conjugate reduction of α,β-unsaturated ketones with tosylhydrazine as a hydrogen source to the corresponding saturated ketones in moderate to good yields. The present protocol does not require the use of transition metal, and is efficient being applicable to a wide range of substrates (25 examples).
- Zhou, Xiaomeng,Li, Xiaokang,Zhang, Wei,Chen, Junmin
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p. 5137 - 5140
(2015/02/19)
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- Glycerol/Hypophosphorous acid and PhSeSePh: An efficient and selective system for reactions in the carbon-carbon double bond of (E)-chalcones
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We describe herein our results for the reaction of benzeneselenol, generated in situ by reaction of diphenyl diselenide with H3PO 2, with various (E)-chalcones using glycerol as solvent. Using our optimized reaction conditions, a range of chemoselective 1,4-reduction products could be obtained in good yields. The glycerol/H3PO2 system can be easily recovered and reused in chemoselective 1,4-reductions for successive cycles without loss of efficiency. Additionally, under 1,4-reducing reaction conditions, the natural product zingerone can be synthesized in good yield. ?2014 Sociedade Brasileira de Qui?mica.
- Mesquita, Katiu?cia D.,Waskow, Bianca,Schumacher, Ricardo F.,Perin, Gelson,Jacob, Raquel G.,Alves, Diego
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p. 1261 - 1269
(2014/08/05)
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- One-pot β-alkylation of secondary alcohols with primary alcohols catalyzed by ruthenacycles
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A ruthenacycle-catalyzed one-pot β-alkylation of secondary alcohols with primary alcohols is described. A survey of four C-N chelate ruthenacycles synthesized via the cyclometallation reaction of phenylmethanamine, N-methylphenylmethanamine, N,N-dimethylphenylmethanamine, and naphthalen-1-ylmethanamine with [(η6-C6H 6)RuCl2]2 was undertaken. All four complexes were found to be active with the phenylmethanamine-based ruthenacycle showing the best combination of reactivity and product selectivity among the four. An expanded scope of substrates was also studied with the inclusion of unsaturated primary alcohols. The reactivity trend observed gave insights into the role of hydrogen bonding in the catalytic mechanism involving transfer hydrogenation between the substrates and the transition metal catalyst.
- Chang, Xu,Chuan, Low Wei,Yongxin, Li,Pullarkat, Sumod A.
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experimental part
p. 1450 - 1455
(2012/04/10)
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- ALLOSTERIC PROTEIN KINASE MODULATORS
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The invention provides specific small molecule compounds that allosterically regulate the activity or modulate protein-protein interactions of AGC protein kinases and the Aurora family of protein kinases, methods for their production, pharmaceutical compositions comprising same, and their use for preparing medicaments for the treatment and prevention of diseases related to abnormal activities of AGC protein kinases or of protein kinases of the Aurora family.
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Page/Page column 58
(2012/03/10)
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- ALLOSTERIC PROTEIN KINASE MODULATORS
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The invention provides specific small molecule compounds that allosterically regulate the activity or modulate protein-protein interactions of AGC protein kinases and the Aurora family of protein kinases, methods for their production, pharmaceutical compositions comprising same, and their use for preparing medicaments for the treatment and prevention of diseases related to abnormal activities of AGC protein kinases or of protein kinases of the Aurora family.
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Page/Page column 120-121
(2010/04/30)
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- Selective 1,4-reduction of chalcones with Zn/NH4Cl/C 2H5OH/H2O
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In this paper, the Zn/NH4Cl/C2H5OH/H 2O system was applied for the selective 1,4-reduction of chalcones undermild conditions with high selectivity. Themerit lies in inexpensive reagent, simple operation and envi
- Li, Jian-Ping,Zhang, Yong-Xia,Ji, Yan
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p. 390 - 393
(2008/12/20)
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- Selective reduction of carbon-carbon double bonds of aryl substituted chalcones with Zn/CH3COONH4/C2H 5OH/H2O
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In this paper, 12 aryl substituted chalcones are easily reduced to the corresponding saturated carbonyl compounds using Zn/CH3COONH 4/C2H5OH/H2O under mild condition with excellent yields for the firs
- Zhou, Yong-Bo,Wang, Yu-Iu,Wang, Jin-Ye
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p. 118 - 119
(2007/10/03)
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- Aryliminodimagnesium Reagents. XI. Two-Electron Oxidation of the Reagent Molecules in the Reaction with Some Oxidizing Agents and with Strongly Push-Pull Substituted α-Benzylideneacetophenones
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The reactions of an aryliminomagnesium reagent (ArN(MgBr)2) with four oxidizing agents ((i): I2, OsO4, C6H5IO2, I2O5) and four push-pull substituted α-benzylideneacetophenones (ii) were examined.In the reactions with (i), the maximum yield of sym-azobenzene was 50percent.In the reactions with (ii), in addition to products formed via condensation and the typical radical processes, unexpected products formed via cleavages of C=C and Cβ-H bonds were observed.Summarizing these results, a pathway involving the formation of arylnitrene-like species via disproportionation of arylaminyl radicals has been proposed.
- Okubo, Masao,Yoshida, Shunsei,Egami, Yoshiji,Matsuo, Koji,Nagase, Shigeru
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p. 1741 - 1746
(2007/10/02)
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