111008-99-2Relevant academic research and scientific papers
Reductive transformation of α β-epoxy ketones and other compounds promoted through photoinduced electron transfer processes with 1,3-dimethyl- 2-phenylbenzimidazoline (DMPBI)
Hasegawa, Eietsu,Yoneoka, Akira,Suzuki, Kumiko,Kato, Teru,Kitazume, Takashi,Yanagi, Kazuhiro
, p. 12957 - 12968 (1999)
Photoreactions of epoxy ketones, aromatic ketones, haloketones, and aromatic halides with 1,3-dimethyl-2-phenylbenzimidazoline (DMPBI) were studied. Photoinduced single-electron transfer from DMPBI to such substrates initiates the reactions, followed by radical rearrangement and reduction to finally give several reduced products in modest to good yields.
Magnetic nano-Fe3O4-supported 1-benzyl-1,4- dihydronicotinamide (BNAH): Synthesis and application in the catalytic reduction of α,β-epoxy ketones
Xu, Hua-Jian,Wan, Xin,Shen, Yong-Ya,Xu, Song,Feng, Yi-Si
, p. 1210 - 1213 (2012)
A novel magnetically recoverable organic hydride compound was successfully constructed by using silica-coated magnetic nanoparticles as a support. An as-prepared magnetic organic hydride compound, BNAH (1-benzyl-1,4- dihydronicotinamide), showed efficient activity in the catalytic reduction of α,β-epoxy ketones. After reaction, the magnetic nanoparticle- supported BNAH can be separated by simple magnetic separation which made the separation of the product easier.
A green and recyclable chitosan supported catalyst for the borylation of α,β-unsaturated acceptors in water
Xu, Pengyu,Li, Bojie,Wang, Liansheng,Qin, Caiqin,Zhu, Lei
, p. 23 - 26 (2016)
We herein report a green and recyclable chitosan supported copper catalyst which is capable of catalyzing the borylation of α,β-unsaturated acceptors in water at room temperature. A broad substrate scope including chalcone derivatives, esters and nitriles have been explored. In all the cases, desired products were obtained in good to excellent yields. Remarkably, this chitosan supported catalyst could be recovered and reused for five times without any significant decrease of reactivity.
Visible light-promoted reductive transformations of various organic substances by using hydroxyaryl-substituted benzimidazolines and bases
Hasegawa, Eietsu,Izumiya, Norihiro,Fukuda, Takuya,Nemoto, Kazuki,Iwamoto, Hajime,Takizawa, Shin-ya,Murata, Shigeru
, p. 7805 - 7812 (2016)
Visible light promoted reduction reactions of organohalides, sulfonamides, organonitriles and epoxy ketones were performed using 1,3-dimethylbenzimidazolines possessing 2-hydroxynaphthyl or 2-hydroxyphenyl substituents (HOAr-DMBIH) as photo-reductants. Xe or Hg–Xe lamp through an appropriate glass-filter (λ>390 nm) and a household white light-emitting diode were used as light sources. In these reactions, reductive cleavages of carbon[sbnd]halogen, nitrogen[sbnd]sulfur, carbon[sbnd]carbon (nitrile) and carbon[sbnd]oxygen bonds take place. Bases exert significant effects on the progress of these reactions in a manner that depends on the nature of the substrate. Addition of 1,8-diazabicyclo[5.4.0]undec-7-ene as well as potassium t-butoxide significantly accelerates photo-reduction reactions of organohalides, sulfonamides and organonitriles while the decomposition of formed hydroxy ketones occurs in reactions of epoxy ketones. Single electron transfer from the photo-excited states of benzimidazolines (HOAr-DMBIH) or their deprotonated analogues (?OAr-DMBIH) to the substrates is proposed to initiate these reactions.
Versatile one-step one-pot direct aldol condensation promoted by MgI 2
Wei, Han-Xun,Li, Kunyu,Zhang, Qian,Jasoni, Richard L.,Hu, Jiali,Pare, Paul W.
, p. 2354 - 2358 (2004)
A true one-step one-pot aldol-reaction procedure has been developed for the synthesis of β-hydroxy ketones and esters. The reaction can be run at room temperature by simply mixing four components in CH2Cl2, with medium-to-high yields of aldol products obtained after regular workup. Mechanistically, the process probably proceeds via Mg-enolate formation of the ketone or ester component, followed by addition to the electrophilic aldehyde.
1,3-Dimethyl-2-phenylbenzimidazoline (DMPBI)-acetic acid: An effective reagent system for photoinduced reductive transformation of α,β-epoxy ketones to β-hydroxy ketones
Hasegawa,Chiba,Nakajima,Suzuki,Yoneoka,Iwaya
, p. 1248 - 1252 (2001)
A combination of 1,3-dimethyl-2-phenylbenzimidazoline (DMPBI) and acetic acid has been utilized for photoinduced reductive transformation of α,β-epoxy ketones to β-hydroxy ketones. Study on photoreactions using several proton donors revealed that acetic acid is superior to other proton donors such as HCl, p-TsOH, MeOH, and water. 1,3-Dimethyl-2-phenylbenzimidazolium was produced in the reaction with acetic acid while N-benzoyl-N,N′-dimethyl-o-phenylenediamine was formed in aqueous solvents. When THF solutions containing aryl carbonyl possessing α,β-epoxy ketones and DMPBI and acetic acid were irradiated (λ > 280 nm), β-hydroxy ketones were isolated in good to excellent yields. Photosensitized conditions (λ > 340 nm) were employed for the reactions of alkyl carbonyl possessing α,β-epoxy ketones.
Catalytic hydrogenation of α,β-epoxy ketones to form β-hydroxy ketones mediated by an NADH coenzyme model
Xu, Hua-Jian,Liu, You-Cheng,Fu, Yao,Wu, Yun-Dong
, p. 3449 - 3451 (2006)
The hydrogenation of α,β-epoxy ketones can be mediated by a catalytic amount of BNAH or BNA+Br- to form corresponding β-hydroxy ketones in high yield. Na2S2O4 is used as the reducing agent to convert
Synthesis method of alpha or beta-substituted aromatic ketone
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Paragraph 0022-0027; 0041-0045, (2021/05/01)
The invention discloses a synthesis method of alpha-or beta-substituted aromatic ketone. The method comprises the following steps: under the condition of inert gas, reacting alpha-oxo-aryl ethanone compounds, B2pin2, PDI-CoCl2 and MBHEt3 in an organic solvent at room temperature, then adding a compound 2, and continuously reacting to obtain a compound 3, wherein in the MBHEt3, M is an alkali metal; the compound 2 is selected from the group consisting of deuterated methanol, Selectfluoro, a TogniII reagent or R2CHO; R2 is an aromatic substituent or alkyl; the organic solvent is an aprotic organic solvent. According to the method, the alpha-oxo aryl ethanone is used as a raw material, a cheap and stable boron reagent and an efficient cobalt catalyst which is cheap and easy to obtain are used, an activating reagent MBHEt3 is added to generate an enol boron ether intermediate, then the enol boron ether intermediate and different electrophilic reagents are synthesized into alpha-or beta-substituted aromatic ketone, the reaction is carried out at normal temperature, and the operation is convenient.
All at once arrangement of both oxygen atoms of dioxygen into aliphatic C(sp3)-C(sp3) bonds for hydroxyketone difunctionalization
Qiao, Xiaofeng,Lin, Yuhan,Li, Jiazhen,Ma, Wanhong,Zhao, Jincai
, p. 770 - 777 (2021/04/09)
Both β- and γ- hydroxyketone structures are important units in biologically active molecules, synthetic drugs and fine chemicals. Although there are some routes available for their manufacture from pre-functionalized groups on one or two matrix molecule(s), the approaches to simply and simultaneously deposit two oxygen atoms from dioxygen into two specific C(sp3) positions of pure saturated hydrocarbons have rarely succeeded because they are involved in the targeted activation of three inert C-H σ bonds all at once. Here, we show that a TiO2-CH3CN photocatalytic suspension system enables the insertion of dioxygen into one C(sp3)-C(sp3) bond of strained cycloparaffin derivatives, by which difunctionalized hydroxyketone products are obtained in a one-pot reaction. With the cleavage event to release strain as the directional driving force, as-designed photocatalytic reaction systems show 21 examples of β-hydroxyketone products with 31%–76% isolated yields for three-membered ring derivatives and 5 examples of γ-hydroxyketone products with 30%–63% isolated yields for four-membered ring substrates. 18O isotopic labeling experiments using 18O2, Ti18O2 and intentionally added H218O, respectively, indicated that both oxygen atoms of hydroxyketone products were exclusively from dioxygen, suggesting a previously unknown H+/TiO2-e? catalyzed arrangement pathway of the hydroperoxide intermediate to convert dioxygen into hydroxyketone units. [Figure not available: see fulltext.]
Basic Anion-Exchange Resin-Catalyzed Aldol Condensation of Aromatic Ketones with Aldehydes in Continuous Flow
Laroche, Benjamin,Saito, Yuki,Ishitani, Haruro,Kobayashi, Shū
supporting information, p. 961 - 967 (2019/05/02)
A general method for the aldol condensation of aromatic ketones with aldehydes was developed under continuous-flow conditions using a commercially available, strongly basic anion-exchange resin (A26) as catalyst. This procedure, in addition to exhibiting a wide substrate scope, promoted carbon-carbon bond formation under mild conditions using a quasi-stoichiometric ratio of starting reagents with good to excellent yields, thereby forming a limited amount of waste and allowing the process to be applied to sequential-flow systems. A proof of concept was developed in the first fully heterogeneously catalyzed two-step flow synthesis of donepezil, which is a blockbuster commercial anti-Alzheimer's drug.
