20615-46-7Relevant academic research and scientific papers
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
Singh, Anshu,Maji, Ankur,Joshi, Mayank,Choudhury, Angshuman R.,Ghosh, Kaushik
, p. 8567 - 8587 (2021/06/30)
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.
Iodine-catalyzed α,β-dehydrogenation of ketones and aldehydes generating conjugated enones and enals
Cao, Yuanjie,Chen, Tieqiao,Huang, Tianzeng,Liu, Long
supporting information, p. 8697 - 8701 (2020/06/08)
A transition metal-free α,β-dehydrogenation of ketones and aldehydes was developed. This reaction was conducted in a facile I2/KI/DMSO system to produce the corresponding unsaturated compounds in good to high yields. The gram-scale experiment also indicated the potential synthetic value of this new reaction in organic synthesis. In the reaction, DMSO acted as both solvent and mild oxidant.
Monodisperse NiPd alloy nanoparticles decorated on mesoporous graphitic carbon nitride as a catalyst for the highly efficient chemoselective reduction of α,β-unsaturated ketone compounds
Bayrak, Cetin,Menzek, Abdullah,Sevim, Melike
, p. 13606 - 13612 (2020/09/07)
Herein, the study reported extraordinary chemoselective reduction with selectivity (>99%) by the catalytic transfer hydrogenation of various α,β-unsaturated ketones with a catalyst of NiPd alloy nanoparticles decorated on mesoporous graphitic carbon nitride (NiPd/mpg-C3N4) under mild conditions in a water/methanol medium. NiPd alloy NPs were synthesized by the reduction of metal salts in oleylamine (OAm) solution with the help of borane-tert-butylamine and then decorated on mpg-C3N4via a liquid phase self-assembly method. The NiPd/mpg-C3N4 nanocatalyst was characterized by TEM, XRD and ICP-MS. The NiPd/mpg-C3N4 nanocatalyst is a highly active catalyst for the chemoselective reduction of α,β-unsaturated ketones and all organic compounds were converted with high yield and 99% selectivity. In addition, the catalyst can be reused five times without an important loss in reaction yield. This journal is
Iridium(I)-Catalyzed C-C and C-N Bond Formation Reactions via the Borrowing Hydrogen Strategy
Gen?, Serta?,Arslan, Burcu,Gülcemal, Süleyman,Günnaz, Salih,?etinkaya, Bekir,Gülcemal, Derya
, p. 6286 - 6297 (2019/05/17)
Iridium(I) complexes having an imidazol-2-ylidene ligand with benzylic wingtips efficiently catalyzed the β-alkylation of secondary alcohols with primary alcohols and acceptorless dehydrogenative cyclization of 2-aminobenzyl alcohol with ketones through a borrowing hydrogen pathway. The β-alkylated alcohols, including cholesterol derivatives, and substituted quinolines were obtained in good yields by using a minute amount of the catalyst with a catalytic amount of NaOH or KOH under the air atmosphere, liberating water (and H2 in the case of quinoline synthesis) as the sole byproduct. Notably, this system demonstrated turnover numbers of 940 000 (for β-alkylation of secondary alcohols with primary alcohols by using down to 0.0001 mol % = 1 ppm of the catalyst) and 9200 (acceptorless dehydrogenative cyclization of 2-aminobenzyl alcohol with ketones).
Catalyst-free chemoselective conjugate addition and reduction of α,β-unsaturated carbonyl compounds: Via a controllable boration/protodeboronation cascade pathway
Huang, Xi,Hu, Junjie,Wu, Mengying,Wang, Jiayi,Peng, Yanqing,Song, Gonghua
, p. 255 - 260 (2018/01/12)
A novel, efficient transition-metal-free and controllable boration/protodeboronation strategy has been developed for the chemoselective conjugate addition and 1,4-reduction of α,β-unsaturated carbonyl compounds. Without any metal-catalyst or base, a series of β-boration products of α,β-unsaturated carbonyl compounds was easily obtained in moderate to excellent yields in a mixed solvent of ethanol and water. The presence of a catalytic amount of Cs2CO3 can effectively induce further protodeboronation reaction towards 1,4-reduction products at higher reaction temperature. Therefore, by slightly changing the reaction conditions, the boration or reduction products of α,β-unsaturated carbonyl compounds can be controllably obtained. Mechanistic studies revealed that Cs2CO3 played the key role in activating the protodeboronation step. This transition-metal-catalyst-free and product controllable method provides a useful and eco-friendly tool for the highly chemoselective preparation of the β-boration products and 1,4-reduction products of α,β-unsaturated carbonyl compounds.
Microbial transformations of 4′-methylchalcones as an efficient method of obtaining novel alcohol and dihydrochalcone derivatives with antimicrobial activity
Koz?owska, Joanna,Potaniec, Bart?omiej,Zarowska, Barbara,Anio?, Miros?aw
, p. 30379 - 30386 (2018/09/11)
Biotransformations are an alternative method of receiving dihydrochalcones as a result of the reduction of α,β-unsaturated ketones-chalcones. In presented research, two strains of bacteria-Gordonia sp. DSM44456 and Rhodococcus sp. DSM364-were selected as
RhCl(CO)(PPh3)2 catalyzed α-alkylation of ketones with alcohols
Wang, Rui,Huang, Lina,Du, Zhengyin,Feng, Hua
supporting information, p. 40 - 43 (2017/06/07)
A simple and efficient method for α-alkylation of ketones with primary alcohols catalyzed by RhCl(CO)(PPh3)2 without additional additives under mild conditions is developed. It has a wide substrate scope, high atom-efficiency and chemoselectivity. It is an environmentally friendly method to build C[sbnd]C bond because water is the only byproduct.
Transition-Metal-Free Self-Hydrogen-Transferring Allylic Isomerization
Zheng, Hong-Xing,Xiao, Zu-Feng,Yao, Chuan-Zhi,Li, Qiang-Qiang,Ning, Xiao-Shan,Kang, Yan-Biao,Tang, Yong
, p. 6102 - 6105 (2016/01/09)
Phenanthroline and tert-butoxide have been established as powerful radical initiators in reactions such as the SRN1-type coupling reactions due to the cooperation of large heteroarenes and a special feature of tert-butoxide. The first phenanthroline-tert-butoxide-catalyzed transition-metal-free allylic isomerization is described. The resulting ketones are key intermediates for indenes. The control experiments rule out the base-promoted allylic anion pathway. The radical pathway is supported by experimental evidence that includes kinetic study, kinetic isotope effect, isotope-labeling experiments, trapping experiments, and EPR experiments.
A novel transition metal-free conjugate reduction of α,β-unsaturated ketones with tosylhydrazine as a hydrogen source
Zhou, Xiaomeng,Li, Xiaokang,Zhang, Wei,Chen, Junmin
supporting information, p. 5137 - 5140 (2015/02/19)
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).
Malononitrile-assisted highly chemoselective bismuth triflate catalyzed conjugate reduction of α,β-unsaturated ketones
Shang, Jun-Yan,Li, Fei,Bai, Xing-Feng,Jiang, Jian-Xiong,Yang, Ke-Fang,Lai, Guo-Qiao,Xu, Li-Wen
supporting information; experimental part, p. 2809 - 2815 (2012/06/18)
A very simple, direct, bismuth-catalyzed conjugate reduction protocol that allows for the catalytic regioselective formation of substituted ketones from enones under mild conditions has been developed. We have shown for the first time that the combined poly(methylhydro)siloxane-malononitrile system can serve as an efficient reductant/reagent in 1,4-conjugate reduction of enones. The regioselectivity, efficiencies, and experimental simplicity of the present method complements the more complex methods previously employed in copper or palladium-catalyzed reduction. This method should prove attractive because of its mild reaction conditions and the interesting chemistry of combining the use of poly(methylhydro)siloxane and malononitrile for selective reduction. Copyright
