16619-28-6Relevant articles and documents
Palladium-Catalyzed Synthesis of α-Methyl Ketones from Allylic Alcohols and Methanol
Biswal, Priyabrata,Samser, Shaikh,Meher, Sushanta Kumar,Chandrasekhar, Vadapalli,Venkatasubbaiah, Krishnan
supporting information, p. 413 - 419 (2021/11/01)
One-pot synthesis of α-methyl ketones starting from 1,3-diaryl propenols or 1-aryl propenols and methanol as a C1 source is demonstrated. This one-pot isomerization-methylation is catalyzed by commercially available Pd(OAc)2 with H2O as the only by-product. Mechanistic studies and deuterium labelling experiments indicate the involvement of isomerization of allyl alcohol followed by methylation through a hydrogen-borrowing pathway in these isomerization-methylation reactions.
Selective C-C bonds formation, N-alkylation and benzo[d]imidazoles synthesis by a recyclable zinc composite
Zhu, Guanxin,Duan, Zheng-Chao,Zhu, Haiyan,Ye, Dongdong,Wang, Dawei
supporting information, p. 266 - 270 (2021/08/06)
Earth abundant metals are much less expensive, promising, valuable metals and could be served as catalysts for the borrowing hydrogen reaction, dehydrogenation and heterocycles synthesis, instead of noble metals. The uniformly dispersed zinc composites were designed, synthesized and carefully characterized by means of XPS, EDS, TEM and XRD. The resulting zinc composite showed good catalytic activity for the N-alkylation of amines with amines, ketones with alcohols in water under base-free conditions, while unsaturated carbonyl compounds could also be synthesized by tuning the reaction conditions. Importantly, it was the first time to realize the synthesis of 2-aryl-1H-benzo[d]imidazole derivatives by using this zinc composite under green conditions. Meanwhile, this zinc catalyst could be easily recovered and reused for at least five times.
Efficient base-free asymmetric one-pot synthesis of spiro[indoline-3,3′-pyrrolizin]-2-one derivatives catalyzed by chiral organocatalyst
Chithiraikumar, Chinnadurai,Ponmuthu, Kottala Vijaya,Harikrishnan, Muniyasamy,Malini, Nelson,Sepperumal, Murugesan,Siva, Ayyanar
, p. 895 - 909 (2020/10/29)
A 1,3-dipolar cycloaddition reaction has been performed under organocatalytic conditions with high enantioselectivity by the utilization of bipyridine-based chiral quaternary ammonium bromide as an organocatalyst. Here, the reaction of 1,3-dipolar cycloaddition of azomethine ylide generated in situ from the decarboxylative condensation of α-amino acids and non-enolizable 1,2-diketones to the above dipolarophiles takes place.
Rapid umpolung Michael addition of isatin N, N ′-cyclic azomethine imine 1,3-dipoles with chalcones
Yue, Guizhou,Jiang, Dan,Dou, Zhengjie,Li, Sicheng,Feng, Juhua,Zhang, Li,Chen, Huabao,Yang, Chunping,Yin, Zhongqiong,Song, Xu,Liang, Xiaoxia,Wang, Xianxiang,Lu, Cuifen
supporting information, p. 11712 - 11718 (2021/07/12)
The umpolung Michael addition of isatin N,N′-cyclic azomethine imine 1,3-dipoles with chalcones is reported. The reaction could be finished within a very short time (0.3-2 min), with 3,3-disubstituted oxindole derivatives obtained in moderate to excellent yields with promising dr values. Unusual Michael adducts were obtained in moderate to high yields (26-98%) with low to high diastereoselectivities (0.8: 1 to 8.5: 1 dr). All the synthesized compounds (3, 3′, 4, 5, 5′, 7, 7′, 9 and 9′) were well characterized by FTIR, NMR, and mass spectral analyses and further confirmed by the single-crystal X-ray diffraction analysis of compounds 3aa and 4n.
Potassium Base-Catalyzed Michael Additions of Allylic Alcohols to α,β-Unsaturated Amides: Scope and Mechanistic Insights
Kurouchi, Hiroaki,Sai, Masahiro
supporting information, p. 3585 - 3591 (2021/06/27)
We report herein the first KHMDS-catalyzed Michael additions of allylic alcohols to α,β-unsaturated amides through allylic isomerization. The reaction proceeds smoothly in the presence of only 5 mol% of KHMDS to afford a variety of 1,5-ketoamides in high yields. Mechanistic investigations, including experimental and computational studies, reveal that the KHMDS-catalyzed in-situ generation of the enolate from the allylic alcohol through a tunneling-assisted 1,2-hydride shift is the key to the success of this transformation. (Figure presented.).
Iridium and copper supported on silicon dioxide as chemoselective catalysts for dehydrogenation and borrowing hydrogen reactions
Zhu, Guanxin,Duan, Zheng-Chao,Zhu, Haiyan,Qi, Minghui,Wang, Dawei
, (2021/04/02)
High active ligand usually plays an important role during catalysis and synthesis chemistry. A new and efficient benzotriazole-pyridinyl-silane ligand (BPS) was designed, and the corresponding iridium and copper catalysts were synthesized and thoroughly characterized by means of EDS, TEM, and XPS. The resulting iridium composite revealed excellent catalytic activity for the reaction of tert-butanesulfinamide with benzyl alcohols, while copper catalyst could realize the synthesis of unsaturated carbonyl compounds through the reaction of benzyl alcohols with ketones. This provided an efficient method for selective synthesis of unsaturated carbonyl compounds from benzyl alcohols and ketones in high yields with good recovery performance.
Diversified Transformations of Tetrahydroindolizines to Construct Chiral 3-Arylindolizines and Dicarbofunctionalized 1,5-Diketones
Feng, Xiaoming,He, Qianwen,Liu, Xiaohua,Pan, Chenjing,Su, Zhishan,Wu, Zhikun,Zhang, Dong,Zhou, Yuqiao
supporting information, p. 15975 - 15985 (2020/10/18)
Enantioselective diverse synthesis of a small-molecule collection with structural and functional similarities or differences in an efficient manner is an appealing but formidable challenge. Asymmetric preparation and branching transformations of tetrahydroindolizines in succession present a useful approach to the construction of N-heterocycle-containing scaffolds with functional group, and stereochemical diversity. Herein, we report a breakthrough toward this end via an initial diastereo- A nd enantioselective [3 + 2] cycloaddition between pyridinium ylides and enones, following diversified sequential transformations. Chiral N,N′-dioxide-earth metal complexes enable the generation of optically active tetrahydroindolizines in situ, across the strong background reaction for racemate-formation. In connection with deliberate sequential transformations, involving convenient rearomatic oxidation, and light-active aza-Norrish II rearrangement, the tetrahydroindolizine intermediates were converted into the final library including 3-arylindolizine derivatives and dicarbofunctionalized 1,5-dicarbonyl compounds. More importantly, the stereochemistry of four-stereogenic centered tetrahydroindolizine intermediates could be efficiently transferred into axial chirality in 3-arylindolizines and vicinal pyridyl and aryl substituted 1,5-diketones. In addition, densely functionalized cyclopropanes and bridged cyclic compounds were also discovered depending on the nature of the pyridinium ylides. Mechanism studies were involved to explain the stereochemistry during the reaction processes.
Unsaturated ketone compound as well as preparation method and application thereof
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Paragraph 0219-0225, (2020/10/30)
The present invention relates to a novel GPR52 antagonist. Specifically, the invention relates to an unsaturated ketone compound, a pharmaceutically acceptable salt, a stereoisomer or a prodrug molecule thereof, and a method for preparing a pharmaceutical composition thereof. The invention further relates to the use of the GPR52 antagonist as an orphan G protein coupled receptor GPR52 antagonist,and further relates to the use of the GPR52 antagonist in the preparation of drugs for preventing and treating Huntington's disease.
Proton-Coupled Electron Transfer: Transition-Metal-Free Selective Reduction of Chalcones and Alkynes Using Xanthate/Formic Acid
Prasanna, Ramanathan,Guha, Somraj,Sekar, Govindasamy
supporting information, p. 2650 - 2653 (2019/04/17)
Highly chemoselective reduction of α,β-unsaturated ketones to saturated ketones and stereoselective reduction of alkynes to (E)-alkenes has been developed under a transition-metal-free condition using a xanthate/formic acid mixture through proton-coupled electron transfer (PCET). Mechanistic experiments and DFT calculations support the possibility of a concerted proton electron-transfer (CPET) pathway. This Birch-type reduction demonstrates that a small nucleophilic organic molecule can be used as a single electron-transfer (SET) reducing agent with a proper proton source.
High pressure-assisted low-loading asymmetric organocatalytic conjugate addition of nitroalkanes to chalcones
Cholewiak, Agnieszka,Adamczyk, Kamil,Kopyt, Micha?,Kasztelan, Adrian,Kwiatkowski, Piotr
supporting information, p. 4365 - 4371 (2018/06/22)
The application of high pressure (up to 9 kbar) allows for relatively fast (1-5 h) and highly enantioselective 1,4-addition of nitromethane and 2-nitropropane to chalcones at room temperature with substantial reduction of catalyst loading (0.2-1 mol% of cinchona alkaloid-based thioureas and squaramides). Various γ-nitroketones were obtained at 9 kbar with high yield and enantioselectivity (up to 98%), whereas in control experiments at atmospheric pressure usually only a small amount (10%) of products were formed after 20 h.
