- Generation and reactivity of phenylhydroxycarbenes in solution
-
We provide evidence for the first successful generation of phenylhydroxycarbene and 4-trifluoromethylphenylhydroxycarbene in solution. The carbene tautomers of the corresponding benzaldehyde derivatives had been prepared under cryogenic matrix-isolation conditions before but their reactivity, apart from a prototypical quantum mechanical tunneling [1,2]-H-shift reaction, had not been studied. Here our strategy is to employ suitable carbene precursors for the McFadyen–Stevens reaction, to generate the parent and the para-CF3-substituted phenylhydroxycarbenes, and to react them with benzaldehyde or acetone in a highly facile, allowed six-electron carbonyl-ene reaction toward the corresponding α-hydroxy ketones. Our findings are supported by computations at the DLPNO-CCSD(T)/cc-pVQZ//B3LYP/def2-TZVP level of theory.
- Keul, Felix,Mardyukov, Artur,Schreiner, Peter R.
-
supporting information
(2022/01/19)
-
- Preparation method of photoinitiator
-
The invention discloses a preparation method of a photoinitiator. The preparation method comprises the following steps: acid chloride required for Fries reaction, aluminum trichloride and a solvent are mixed and then subjected to a Fourier reaction with benzene. Fries reaction intermediate purification method The Fourier reaction intermediate is mixed with chlorine for chlorination reaction, and the product of the chlorination reaction is subjected to gas-liquid separation to separate the gas. Reaction Section Step and The product purification step results in a photoinitiator finished product. To the technical scheme of the invention, the advantages of the traditional process of producing the photoinitiator are combined with the characteristics of the microchannel reactor to realize continuous preparation, the productivity can be improved, the production risk is reduced, the manpower and equipment investment are reduced, and the cost is further reduced.
- -
-
Paragraph 0034-0073
(2021/10/13)
-
- 1,5,7-Triazabicyclo[4.4.0]dec-5-ene Enhances Activity of Peroxide Intermediates in Phosphine-Free α-Hydroxylation of Ketones
-
The critical role of double hydrogen bonds was addressed for the aerobic α-hydroxylation of ketones catalyzed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), in the absence of either a metal catalyst or phosphine reductant. Experimental and theoretical investigations were performed to study the mechanism. In addition to initiating the reaction by proton abstraction, a more important role of TBD was revealed, that is, to enhance the oxidizing ability of peroxide intermediates, allowing DMSO to be used rather than commonly used phosphine reductants. Further characterizations with nuclear Overhauser effect spectroscopy (NOESY) confirmed the presence of double hydrogen bonds between TBD and the ketone, and kinetic studies suggested the attack of dioxygen on the TBD-enol adduct to be the rate-determining step. This work should encourage the application of TBD as a catalyst for oxidations.
- Wang, Yongtao,Lu, Rui,Yao, Jia,Li, Haoran
-
supporting information
p. 6631 - 6638
(2021/02/05)
-
- Competitive Desulfonylative Reduction and Oxidation of α-Sulfonylketones Promoted by Photoinduced Electron Transfer with 2-Hydroxyaryl-1,3-dimethylbenzimidazolines under Air
-
Desulfonylation reactions of α-sulfonylketones promoted by photoinduced electron transfer with 2-hydroxyarylbenzimidazolines (BIH-ArOH) were investigated. Under aerobic conditions, photoexcited 2-hydroxynaphthylbenzimidazoline (BIH-NapOH) promotes competitive reduction (forming alkylketones) and oxidation (producing α-hydroxyketones) of sulfonylketones through pathways involving the intermediacy of α-ketoalkyl radicals. The results of an examination of the effects of solvents, radical trapping reagents, substituents of sulfonylketones, and a variety of hydroxyaryl- and aryl-benzimidazolines (BIH-ArOH and BIH-Ar) suggest that the oxidation products are produced by dissociation of α-ketoalkyl radicals from the initially formed solvent-caged radical ion pairs followed by reaction with molecular oxygen. In addition, the observations indicate that the reduction products are generated by proton or hydrogen atom transfer in solvent-caged radical ion pairs derived from benzimidazolines and sulfonylketones. The results also suggest that arylsulfinate anions arising by carbon-sulfur bond cleavage of sulfonylketone radical anions act as reductants in the oxidation pathway to convert initially formed α-hydroperoxyketones to α-hydroxyketones. Finally, density functional theory calculations were performed to explore the structures and properties of radical ions of sulfonylketones as well as BIH-NapOH.
- Hasegawa, Eietsu,Nakamura, Shyota,Oomori, Kazuki,Tanaka, Tsukasa,Iwamoto, Hajime,Wakamatsu, Kan
-
p. 2556 - 2569
(2021/02/27)
-
- Photocatalytic Reductive Radical-Polar Crossover for a Base-Free Corey–Seebach Reaction
-
A metal-free generation of carbanion nucleophiles is of prime importance in organic synthesis. Herein we report a photocatalytic approach to the Corey–Seebach reaction. The presented method operates under mild redox-neutral and base-free conditions giving the desired product with high functional group tolerance. The reaction is enabled by the combination of photo- and hydrogen atom transfer (HAT) catalysis. This catalytic merger allows a C?H to carbanion activation by the abstraction of a hydrogen atom followed by radical reduction. The generated nucleophilic intermediate is then capable of adding to carbonyl electrophiles. The obtained dithiane can be easily converted to the valuable α-hydroxy carbonyl in a subsequent step. The proposed reaction mechanism is supported by emission quenching, radical–radical homocoupling and deuterium labeling studies as well as by calculated redox-potentials and bond strengths.
- Crespi, Stefano,Donabauer, Karsten,K?nig, Burkhard,Murugesan, Kathiravan,Rozman, Ur?a
-
supporting information
p. 12945 - 12950
(2020/09/23)
-
- Preparing method of photoinitiator 2-methyl-2-hydroxy-1-phenylacetone
-
The invention discloses a preparing method of a photoinitiator 2-methyl-2-hydroxy-1-phenylacetone. The preparing method comprises the steps of conducting acylation reaction on isobutyric acid and phosphorus trichloride, after the reaction is completed, introducing hydrogen chloride gas to make the intermediate state reaction complete, obtaining 2-chloride-2-methyl propionylchloride through chlorination reaction, conducting Friedel-Crafts reaction with benzene in the presence of a catalyst to obtain 2-chloride-2-methyl-1-phenylpropane-1-ketone, and finally after alkaline hydrolysis, washing anddistillation, obtaining the photoinitiator 1173. According to the preparing method, hydrogen chloride is introduced into the acylation step, so that the reaction yield is increased, and byproduct odors are reduced; meanwhile, chlorination reaction of a conventional technology is conducted one step in advance, the production cost of the conventional technology is reduced, and thus the product hasmarket competitiveness.
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-
Page/Page column 4-6
(2019/04/30)
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- Ultrasonic preparation method for alpha-hydroxyketones
-
The invention relates to the technical field of organic synthesis, and concretely relates to an ultrasonic preparation method for alpha-hydroxyketones. Ketones and peroxide which are used as raw materials undergo an ultrasonic reaction in the presence of an organic solvent to prepare the alpha-hydroxyketones. The preparation method provided by the invention avoids the use of halogens with high toxicity and high risks in the reaction process to avoid the risk of the product not meeting the requirements of the regulations due to the introduction of the halogens in the reaction process, and alsohas the advantages of low cost of the overall process, shortening of the cycle of batch production, simplicity in process operation and easiness in achieving of large-scale production.
- -
-
Paragraph 0028; 0031
(2019/05/11)
-
- Expedient preparation of active pharmaceutical ingredient ketamine under sustainable continuous flow conditions
-
A robust three-step continuous flow procedure is presented for the efficient and sustainable preparation of active pharmaceutical ingredient ketamine. The procedure relies on the main assets of continuous flow processing, starts from commercially available chemicals, utilizes low toxicity reagents and a FDA class 3 solvent under intensified conditions. The procedure features a unique hydroxylation step with molecular oxygen, a fast imination relying on triisopropyl borate and a thermolysis employing Montmorillonite K10 as a heterogeneous catalyst, all three steps being performed in ethanol. The three individual steps can be run independently or can be concatenated, thus providing a compact yet efficient setup for the production of ketamine. The scalability of the critical hydroxylation step was assessed in a commercial pilot continuous flow reactor. The process can also be adapted for the preparation of ketamine analogs. A thorough computational study on the backbone rearrangement of the cyclopentylphenylketone scaffold under thermal stress rationalizes the experimental selectivity and the various experimental observations reported herein.
- Kassin, Victor-Emmanuel H.,Gérardy, Romaric,Toupy, Thomas,Collin, DIégo,Salvadeo, Elena,Toussaint, Fran?ois,Van Hecke, Kristof,Monbaliu, Jean-Christophe M.
-
supporting information
p. 2952 - 2966
(2019/06/18)
-
- Preparation method of alpha-hydroxyketone photoinitiator
-
The invention provides a preparation method of an alpha-hydroxyketone photoinitiator. The preparation method comprises the steps of taking a ketone compound and a trihalomethyl-substituted benzene anda derivative thereof as raw materials, enabling the raw materials to react under the action of a polar solvent and a metal catalyst to form a halogenated intermediate in one step, and hydrolyzing theobtained product under the action of an alkali metal hydroxide aqueous solution and a phase transfer catalyst to obtain the alpha-hydroxyketone photoinitiator. The operation is simple, the reaction step is short, no Lewis acid catalyst is used in the reaction, the pollution is small, the catalyst can be recycled, by-products are less, the cost is low, and a variety of products can be produced bythe same method.
- -
-
Paragraph 0043-0045
(2019/07/04)
-
- Process for preparing photoinitiator 1173
-
The invention discloses a process for preparing a photoinitiator 1173 (2-hydroxy-2-methyl-1-phenyl-1-acetone). The process comprises the following steps: a procedure of preparing ketone at a high temperature, namely liquefying and mixing benzoic acid and isobutyric acid so as to obtain a reaction mixed liquid, preheating the reaction mixed liquid, contacting with a metallic salt catalyst, carryingout dehydration at a high temperature of 300-500 DEG C so as to remove carbon dioxide to prepare ketone, thereby obtaining isobutyryl benzene; and a procedure of one-pot method chlorination alkalinehydrolysis, namely by taking the isobutyryl benzene, carbon tetrachloride and sodium hydroxide as reagents and tetrabutylammonium bromide as a phase change catalyst, carrying out a one-pot method chlorination and alkaline hydrolysis reaction, thereby obtaining the 2-hydroxy-2-methyl-1-phenyl-1-acetone. The process disclosed by the invention is high in selectivity, and safe and environment-friendly.
- -
-
Paragraph 0039; 0044; 0045; 0048
(2018/12/14)
-
- PROCESS FOR THE PREPARATION OF ALPHA-FUNCTIONALIZED KETONES
-
The present invention refers to a process for the preparation of an α-functionalized ketone, an α-functionalized ketone obtained by said process, a photopolymerizable composition comprising the α-functionalized ketone and at least one photopolymerizable unsaturated compound, a method of preparing an article, an article obtained by said method, as well as the use of the α-functionalized ketone or the photopolymerizable composition as photoinitiator.
- -
-
Page/Page column 43
(2018/11/22)
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- Alpha-hydroxy ketone photoinitiator preparation method
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The invention relates to an alpha-hydroxy ketone photoinitiator preparation method and specifically relates to a method of utilizing ketone as a raw material to react with hydrogen peroxide under microwave radiation to prepare an alpha-hydroxy ketone photoinitiator. According to the preparation method disclosed by the invention, halogen with strong toxicity and large danger is avoided in a reaction process, and the risk that a product cannot comply with laws and regulations as the halogen is introduced in the reaction process is avoided; meanwhile, the whole technology has the advantages of low cost, simple technological operation and easiness in achieving industrial production.
- -
-
Paragraph 0015
(2018/04/03)
-
- Furyl o-diketone derivative and preparation method thereof
-
The invention discloses a furyl o-diketone derivative and a preparation method thereof. The furyl o-diketone derivative comprises a furyl o-diketone parent structure, meanwhile comprises a plurality of modifiable groups such as aryl groups and thioether groups, and is a novel drug intermediate. The synthesis method for the furyl o-diketone derivative is characterized in that aryl or aromatic heterocyclic acetone compounds are subjected to cyclization reaction in a dimethyl sulfoxide solution system containing persulfate and halogen elementary substances and/or haloid so as to obtain the furylo-diketone derivative. According to the method, cheap aryl acetone and dimethyl sulfoxide are used as raw materials, the reaction conditions are mild, the reaction is completed through a one-pot method without the catalytic action of heavy metal or noble metal, in addition, the reaction yield is high, and the industrial production is facilitated.
- -
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Paragraph 0140; 0141
(2018/09/11)
-
- Polysubstituted furan derivative synthesis method
-
The invention discloses a polysubstituted furan derivative synthesis method. A polysubstituted furan derivative comprises a furyl o-diketone matrix structure and a plurality of modifiable groups suchas aryl and a thioether group and is a novel drug intermediate. The synthesis method is characterized in that an ethyl phenyl ketone compound is subjected to cyclization reaction in a dimethyl sulfoxide solution system containing persulfate and iodine and/or bromine to obtain the polysubstituted furan derivative. Low-cost ethyl phenyl ketone and dimethyl sulfoxide serve as raw materials, reactionconditions are mild, synthesis is finished by a one-pot method without the catalytic action of heavy metals or precious metals, reaction yield is high, and industrial production is facilitated.
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Paragraph 0132
(2018/11/03)
-
- Preparation method of compound
-
The invention discloses a preparation method of a hydroxyalkyl phenyl ketone compound. The preparation method comprises the steps: enabling a reactant shown in formula (II) or formula (II') to react with a cyano-containing compound shown in formula (III) in an organic solvent. The preparation method provided by the invention is relatively high in yield.
- -
-
Paragraph 0066; 0068; 0069
(2018/07/07)
-
- New synthesis technology for photoinitiator1173
-
The invention relates to a midbody isobutyrophenone of a photoinitiator1173 (2-hydroxy-2-methyl-1-phenyl-1-acetone) and a new synthesis technology for a photoinitiator1173. The new synthesis technology includes the steps that isobutylbenzene serves as a raw material, an oxidizing reaction is carried out with oxygen under the catalytic effect of catalyst cobalt salt or palladium salt, and the isobutyrophenone is obtained; the isobutyrophenone is further chloridized and hydrolyzed with a sodium hydroxide solution, and the photoinitiator1173 is obtained. The influence of the catalyst cobalt salt or palladium salt on isobutyrophenone production in the reaction is inspected, the material ratio in the isobutyrophenone and photoinitiator1173 production is determined, and the new technology is easy to operate and economical.
- -
-
Paragraph 0021; 0026; 0030
(2017/06/02)
-
- Alpha-hydroxy-ketone compound synthesis method
-
The invention discloses an alpha-hydroxy-ketone compound synthesis method. In the prior art, a noble metal complex, an organophosphorus compound or an iodine elementary substance is always used as a catalyst, the price is high and the recycle cost is higher; used alkali is organic alkali with a complex structure or unusual inorganic alkali such as cesium carbonate which is high in price; a used solvent is always selected from aprotic organic solvents, the post-treatment is complex, and industrialized application is difficult to realize. According to the alpha-hydroxy-ketone compound synthesis method provided by the invention, common inorganic sulfocompounds with low price are adopted as the catalyst, under the alkali and aerobic condition, a carbonyl compound is catalyzed to react to obtain the alpha-hydroxy-ketone compound. The invention has the advantages that the used raw materials are easy to obtain, the price is low, the yield is high, the product purity is high, the waste amount is less and easy to treat, and industrialization is easy to realize.
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Paragraph 0039; 0040; 0041; 0042; 0043
(2017/07/19)
-
- Α - hydroxy ketone compound low priced high-efficient synthetic method
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The invention discloses a cheap and efficient synthesis method of an alpha-hydroxyketone compound. The synthesis method is characterized in that a carbonyl compound undergoes an oxidation hydroxylation reaction at 10-120DEG C under normal pressure with iodine simple substance, N-bromosuccimide, copper bromide, bromine simple substance, hydrogen bromide, N-iodosuccimide or hydrogen iodide as a catalyst, sulfoxide as an oxidant, water or sulfoxide as a hydroxy source and sulfoxide, ethyl acetate, N,N-dimethyl formamide, acetonitrile, toluene, 1,4-dioxane, 1,2-dichloroethane, tetrahydrofuran or H2O as a solvent, and converts into the alpha-hydroxyketone compound in a high selectivity manner. Compared with traditional synthesis methods, the method disclosed in the invention has the advantages of simple operation, high yield, simple conditions, easy purification, small waste discharge amount, simple reaction apparatus, and easy industrial production. The method has wide applicability and can be used for synthesizing various alpha-hydroxyketone compounds.
- -
-
Paragraph 0153-0157
(2017/08/25)
-
- Transition-Metal-Free C-H Hydroxylation of Carbonyl Compounds
-
Transition metal and reductant free α-C(sp3)-H hydroxylation of carbonyl compounds are reported. This method is promoted by commercially available inexpensive KO-t-Bu and atmospheric air as an oxidant at room temperature. This unified strategy is also very facile for hydroxylation of various carbonyl compound derivatives to obtain quaternary hydroxyl compounds in excellent yield. A preliminary mechanistic investigation, supported by isotope labeling and computational studies, suggests the formation of a peroxide bond and its cleavage by in situ generated enolate.
- Chaudhari, Moreshwar B.,Sutar, Yogesh,Malpathak, Shreyas,Hazra, Anirban,Gnanaprakasam, Boopathy
-
supporting information
p. 3628 - 3631
(2017/07/15)
-
- N,N-Dimethylformamide (DMF) as a Source of Oxygen to Access α-Hydroxy Arones via the α-Hydroxylation of Arones
-
An unprecedented α-hydroxylation strategy was developed for the synthesis of α-hydroxy arones using N,N-dimethylformamide (DMF) as an oxygen source. Control experiments demonstrated that the oxygen atom of the hydroxy group in the α-hydroxy arones produced in this reaction was derived from DMF. This new reaction therefore not only provides an alternative strategy for the α-hydroxylation of arones but also highlights the possibility of using the inexpensive common solvent DMF as a source of oxygen in organic synthesis.
- Liu, Weibing,Chen, Cui,Zhou, Peng
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p. 2219 - 2222
(2017/02/26)
-
- Halogen-bonded iodonium ion catalysis: A route to α-hydroxy ketones: Via domino oxidations of secondary alcohols and aliphatic C-H bonds with high selectivity and control
-
A domino synthesis of α-hydroxy ketones has been developed from benzylic secondary alcohols employing catalytic iodonium ions stabilized by DMSO. The reaction proceeds through an unprecedented sequential oxidation of alcohols to ketone and its α-hydroxylation in a controlled manner. The spectroscopic evidence establishes the possibility of formation of a stable halogen-bonded adduct between DMSO and iodonium ions.
- Guha, Somraj,Kazi, Imran,Mukherjee, Pranamita,Sekar, Govindasamy
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p. 10942 - 10945
(2017/10/13)
-
- PROCESS FOR PREPARING ARYL KETONE
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A process for preparing aryl ketones is disclosed. The process includes photo-oxidizing a compound of formula (V), (VI), (VII) or (VIII): in the presence of an oxidative system comprising at least one bromide compound to form aryl ketones. X1, X2, R1, R2, R3, L1, L2, L3, L4, t, n, m and p have the meanings as described in the specification and claims.
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-
-
- 2-hydroxy-2-methyl-1-phenyl-1-propyl ketone synthesis process
-
The present invention discloses a 2-hydroxy-2-methyl-1-phenyl-1-propyl ketone synthesis process, which is characterized in that isobutyric acid is adopted as a raw material, an acylation reaction, a Friedel-Crafts reaction, and an alkaline hydrolysis reaction are performed to obtain a 2-hydroxy-2-methyl-1-phenyl-1-propyl ketone crude product, and fine steaming is performed to obtain the 2-hydroxy-2-methyl-1-phenyl-1-propyl ketone finished product. According to the present invention, the process is reasonable, no sulfur dioxide gas emits during the production process, the environmental pollution caused by the produced sodium chloride is low, and the product yield is high.
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-
Paragraph 0010
(2017/06/21)
-
- ERK INHIBITORS
-
The present invention provides a compound of Formula (I) or the pharmaceutically acceptable salts, esters, and prodrugs thereof, which are ERK2 inhibitors. The invention also provides a method of inhibiting ERK2 in a patient in need of such treatment comprising administering to said patient an effective amount of at least one compound of Formula (I). The invention also provides a method for treating cancer in a patient in need of such treatment, said method comprising administering to said patient an effective amount of at least one compound of Formula (I).
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Page/Page column 66-67
(2016/07/05)
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- Green organocatalytic α-hydroxylation of ketones
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An efficient and green method for the α-hydroxylation of substituted ketones has been developed. This method includes the in situ conversion of various ketones into the corresponding silyl enol ethers and their oxidation to the corresponding α-hydroxy ketones. Two protocols have been established leading either to protected α-hydroxy carbonyls or free α-hydroxy ketones. Both procedures are easy to follow and lead to good to high yields for a variety of ketones.
- Voutyritsa, Errika,Theodorou, Alexis,Kokotos, Christoforos G.
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p. 5708 - 5713
(2016/07/06)
-
- Copper-Catalyzed Formation of α-Alkoxycycloalkenones from N-Tosylhydrazones
-
The combination of 20 mol % of copper iodide and lithium tert-butoxide triggers the formation of a broad range of substituted, functionalized α-alkoxy 2H-naphthalenones from readily available N-tosylhydrazones. The data suggests that this transformation occurs through cycloaddition of a copper carbenoid with an ester, followed by a Lewis acid-catalyzed [1,2] alkyl shift of the in situ generated alkoxyepoxide intermediate. The combination of 20 mol % of copper iodide and lithium tert-butoxide triggers the formation of a broad range of substituted, functionalized α-alkoxy 2H-naphthalenones from readily available N-tosylhydrazones. The reaction proceeds by the cycloaddition of a copper carbenoid with an ester, and a subsequent Lewis acid-catalyzed [1,2] alkyl shift of the in situ generated alkoxyepoxide intermediate.
- Su, Naijing,Theorell, Juliana A.,Wink, Donald J.,Driver, Tom G.
-
p. 12942 - 12946
(2015/11/02)
-
- SUSTAINED DRUG DELIVERY SYSTEM
-
Disclosed is a drug delivery system for delivering a drug at a sustained constant rate for a long period, which can be transplanted into an affected part safely and in a simple manner and can deliver a drug to the affected part for a long period. Specifically disclosed is a sustained drag delivery system in which an implant is implanted into a body, wherein the implant is a PEG capsule comprising a box-shaped PEG and a porous PEG sheet, and wherein the box-shaped PEG has, encapsulated therein, a solution of a therapeutic drug, a collagen impregnated with the therapeutic drug, or a PEG pellet including the collagen impregnated with the therapeutic drug, and the PEG capsule has such a structure that the box-shaped PEG is covered with the porous PEG sheet so that the drug contained in the PEG capsule can be released through the porous PEG sheet in a sustained manner.
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-
-
- I2- or NBS-catalyzed highly efficient α-hydroxylation of ketones with dimethyl sulfoxide
-
An efficient method for the direct preparation of high synthetic valuable α-hydroxycarbonyls is described. The simple and readily available I2 or NBS was used as catalyst. DMSO acts as the oxidant, oxygen source, and solvent. A diverse range of tertiary Csp3-H bonds as well as more challenging secondary Csp3-H bonds could be hydroxylated in this transformation. The reaction is mild, less toxic and easy to perform.
- Liang, Yu-Feng,Wu, Kai,Song, Song,Li, Xinyao,Huang, Xiaoqiang,Jiao, Ning
-
supporting information
p. 876 - 879
(2015/04/14)
-
- Tetra-n-butylammonium bromide: A simple but efficient organocatalyst for alcohol oxidation under mild conditions
-
A simple but efficient organocatalytic system with 5 mol% tetra-n-butylammonium bromide (TBAB) as the catalyst has been identified for alcohol oxidation for the first time. This organocatalytic system is compatible with a broad range of benzylic/allylic alcohols with various catalytically reactive groups. Besides, it shows excellent selectivity for secondary benzylic alcohols over aliphatic alcohols, and good selectivity over the primary benzylic alcohol site in 4-(1-hydroxyethyl)benzyl alcohol. Thus, the features of simplicity, high efficiency, selectivity and mildness of reaction conditions associated with this TBAB organocatalytic system suggest its potential for widespread use in synthetic chemistry.
- Ma, Xinyi,Li, Zhongfeng,Liu, Feijie,Cao, Shengli,Rao, Honghua
-
supporting information
p. 1741 - 1746
(2014/06/09)
-
- Highly efficient C-H hydroxylation of carbonyl compounds with oxygen under mild conditions
-
A transition-metal-free Cs2CO3-catalyzed α-hydroxylation of carbonyl compounds with O2 as the oxygen source is described. This reaction provides an efficient approach to tertiary α-hydroxycarbonyl compounds, which are highly valued chemicals and widely used in the chemical and pharmaceutical industry. The simple conditions and the use of molecular oxygen as both the oxidant and the oxygen source make this protocol very environmentally friendly and practical. This transformation is highly efficient and highly selective for tertiary C(sp3)-H bond cleavage. OH, so simple! A transition-metal-free Cs2CO 3-catalyzed α-hydroxylation of carbonyl compounds with O 2 provided a variety of tertiary α-hydroxycarbonyl compounds (see scheme; DMSO=dimethyl sulfoxide), which are widely used in the chemical and pharmaceutical industry. The simple conditions and the use of molecular oxygen as both the oxidant and the oxygen source make this protocol very efficient and practical.
- Liang, Yu-Feng,Jiao, Ning
-
supporting information
p. 548 - 552
(2014/01/23)
-
- ENVIRONMENTALLY-FRIENDLY NEW OXIDATION PROCESS FOR CONVERTING ARYL-1,2-DIOL TO KETONE
-
The present invention relates to the technical field of radiation curing photopolymerization initiator, and particularly to an environmentally-friendly new oxidation process for converting several specific aryl-1,2-diol compounds to corresponding arylhydroxyketones.
- -
-
Paragraph 0016; 0017; 0018; 0019; 0020; 0021
(2013/11/19)
-
- Control of transient aluminum-aminals for masking and unmasking reactive carbonyl groups
-
A new reagent, the dimethylaluminum N,O-dimethylhydroxylamine complex, is effective at masking reactive carbonyl groups in situ from nucleophilic addition. This reagent allows chemoselective addition of reducing reagents, Grignard reagents, organolithiums, Wittig reagents, and enolates into substrates with multiple carbonyl groups. Moreover, the trapped carbonyl group, a stable aminal, can be unmasked in situ for additional synthetic manipulations.
- Barrios, Francis J.,Springer, Brannon C.,Colby, David A.
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supporting information
p. 3082 - 3085
(2013/07/26)
-
- A dinuclear palladium catalyst for α-Hydroxylation of carbonyls with O2
-
A chemo- and regioselective α-hydroxylation reaction of carbonyl compounds with molecular oxygen as oxidant is reported. The hydroxylation reaction is catalyzed by a dinuclear Pd(II) complex, which functions as an oxygen transfer catalyst, reminiscent of an oxygenase. The development of this oxidation reaction was inspired by discovery and mechanism evaluation of previously unknown Pd(III)-Pd(III) complexes.
- Chuang, Gary Jing,Wang, Weike,Lee, Eunsung,Ritter, Tobias
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supporting information; experimental part
p. 1760 - 1762
(2011/04/15)
-
- Polymer-supported synthesis of α- and β-hydroxyketones through the formation of 1,3-dithiane intermediates
-
The synthesis of polymer-supported 2-monosubstituted 1,3-dithianes from soluble copolymers bearing 1,3-propanedithiol groups, their lithiation, reactions with electrophiles such as aldehydes, ketones, α,β- unsaturated ketones and oxiranes, and cleavage of
- Bertini, Vincenzo,Lucchesini, Francesco,Pocci, Marco,Alfei, Silvana,Idini, Barbara
-
body text
p. 1141 - 1144
(2009/04/06)
-
- Organic-inorganic hybrid polymer-encapsulated magnetic nanobead catalysts
-
A new strategy for the encapsulation of magnetic nanobeads was developed by using the in situ self-assembly of an organic-inorganic hybrid polymer. The hybrid polymer of {[Cu-(bpy)(BF4)2(H2O) 2](bpy)}n (bpy = 4,4′-bipyridine) was constructed on the surface of amino-functionalized magnetic beads and the resulting hybrid-polymer-encapsulated beads were utilized as catalysts for the oxidation of silyl enolates to provide the corresponding α-hydroxy carbonyl compounds in high yield. After the completion of the reaction, the catalyst was readily recovered by magnetic separation and the recovered catalyst could be reused several times. Because the current method did not require complicated procedures for incorporating the catalyst onto the magnetic beads, the preparation and the application of various other types of organic-inorganic hybrid-polymer-coated magnetic beads could be possible.
- Arai, Takayoshi,Sato, Toru,Kanoh, Hirofumi,Kaneko, Katsumi,Oguma, Koichi,Yanagisawa, Akira
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p. 882 - 885
(2008/09/21)
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- PREPARATION OF ALPHA-HYDROXYKETONES
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A process for the preparation of an 1, 1 -disubstituted oxirane is disclosed, wherein an organic sulphide is reacted in a polar solvent with an educt containing a leaving group attached to a primary or secondary carbon atom, and/or the sulfonium salt formed in this way is reacted with a ketone in presence of a base and a polar solvent. Oxiranes of the type obtained may be further converted into the corresponding α-hydroxyketone or α-aminoketone, either in one step by subjecting to aerobic oxidation in the presence of a transition metal catalyst, or in two steps by hydrolyzation in the presence of an aqueous acid to the corresponding dialcohol and subsequent selective oxidation. Further described are some novel epoxide intermediates. The α-hydroxyketones and α-aminoketones thus obtainable are useful inter alga as photoinitiators.
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-
-
- Catalytic synthesis of α-hydroxy ketones using organic-inorganic hybrid polymer
-
Oxidation of silyl enolates was found to be smoothly catalyzed by [Cu(bpy)(BF4)2(H2O)2(bpy)] n (bpy = 4,4′-bipyridine) under molecular oxygen, and provided the corresponding α-hydroxy carbonyl compounds in high yield. The insoluble organic-inorganic hybrid polymer was readily recovered by centrifugation after the completion of reaction, and the recovered catalyst could be reused. Copyright
- Arai, Takayoshi,Takasugi, Hitomi,Sato, Toru,Noguchi, Hiroshi,Kanoh, Hirofumi,Kaneko, Katsumi,Yanagisawa, Akira
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p. 1590 - 1591
(2007/10/03)
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- Molecular complex compounds of acylphosphine oxide and α-hydroxy ketones as photoinitiators
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Molecular complex compounds comprising a mono-, bis- or trisacylphosphine oxide compound with an α-hydroxy ketone compound are suitable as photoinitiators for the photopolymerization of free-radically polymerizable compounds.
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- Reactivity and Selectivity in the Oxidation of Styrene Derivatives. IV. Studies on the Oxidation of Substituted β,β-Dimethylstyrenes
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The liquid phase oxidation of substituted (p-MeO-, p-Cl-, m-CF3-) 2-aryl-3-methyl-but-2-enes, of 1,1-diphenyl-2-methyl-propene, of 1-ethoxy-2-methyl-1-phenyl-propene and of 9-isopropylidene-fluorene with pure oxygen was investigated in chlorobenzene solution and in presence of cumene and of cumene hydroperoxide in the temperature range 65-125°C. The product yields were determined gaschromatographically. The differences of the activation energies of epoxide formation and the parallel reactions were calculated. They amount to 19-48 kJ/mol. The epoxide selectivity increases with increasing temperature and increasing concentration of olefin. The relative chain propagation constants (kpC=C) were determined by competitive oxidation with cumene. The kpC=C values of substituted β,β-dimethylstyrenes can be correlated by a LFE-relationship with the ionisation energies of the olefins.
- Suprun
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p. 247 - 255
(2007/10/03)
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- Alkylation of Nitrile Anions by Tertiary α-Halo Ketones and Nitriles
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Potassium salts of nitriles bearing carbethoxy, cyano, or phenyl groups at the α carbon react with tertiary α-halo ketones and nitriles (1-5) in DMSO or HMPA to provide the alkylated β-keto- or β-cyano-β,β-dialkyl nitriles 6-10 in useful yields. (PhCHCN)(-) undergoes cyclization with p-XC6H4COCCl(CH3)2 to produce 2(5H)-furanone 11.Reaction of (Ph2CCN)(-) with PhCOCCl(CH3)2 affords the hydrolyzed ketone 12a and recovered carbon acid, while the anion undergoes oxidative dimerization to NCCPh2CPh2CN with p-O2NC6H4COCCl(CH3)2 with concomitant formation of the reduced ketone p-O2NC6H4COCH(CH3)2 and the hydrolyzed ketone 12b.The alkylations of (-) and (-) with p-O2NC6H4COCX(CH3)2 take place by the SRN1 process.
- Ros, Francisco,Rosa, Jose de la,Enfedaque, Juan
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p. 5419 - 5424
(2007/10/02)
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- Oxygen-containing titanocenes, and the use thereof
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Titanocenes of the formula I STR1 in which R1 are cyclopentadienyl? groups and R2 and R3 are aromatic radicals which are substituted in both ortho-positions by fluorine and, in addition, are substituted by an acyloxy group are suitable as photoinitiators for the photopolymerization of ethylenically unsaturated compounds.
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- Reductive Coupling of Benzoyl Cyanide and Carbonyl Compounds by Aqueous Ti(III) Ions. A New Convenient and Selective Access to the Less Stable Mixed Benzoins
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The reactive species formed by the Ti(III) ion reduction of benzoyl cyanide (1) adds to the C-atom of carbonyl compounds 2 under simple experimental conditions.The intermediate 1,2-diols 3 are smoothly converted, without isolation, into the less thermodynamically stable mixed benzoins 4, which are not accessible by the classical benzoin condensation.The possible mechanisms involved in the reaction are discussed.
- Clerici, Angelo,Porta, Ombretta
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p. 2889 - 2893
(2007/10/02)
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- Titanocenes, the use thereof, and n-substituted fluoroanilines
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Titanocenes containing two 5-membered cyclodienyl gropus, for example cyclopentadienyl, and one or two 6-membered carbocyclic or 5- or 6-membered heterocyclic aromatic rings which are substituted by a fluorine atom in at least one of the two ortho-positions to the titanium-carbon bond and contain, as further substituents, a substituted amino radical, are suitable as photoinitiators for radiation-induced polymerization of ethylenically unsaturated compounds.
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- Titanocenes, the use thereof, and N-substituted pyrroles
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Titanocenes containing two 5-membered cyclodienyl groups, for example cyclopentadienyl, and one or two 6-membered carbocyclic or 5- or 6-membered heterocyclic aromatic rings which are substituted by a fluorine atom in at least one of the two ortho-positions to the titanium-carbon bond and contain, as a further substituent, unsubstituted or substituted 1-pyrryl, are suitable as photoinitiators for radiation-induced polymerization of ethylenically unsaturated compounds.
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- Novel nitrogen-containing titanocenes, and the use thereof
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Titanocenes of the formula I STR1 in which R1 are cyclopentadienyl? groups and R2 and R3 are aromatic radicals which are substituted in both ortho-positions by fluorine and, in addition, are substituted by a pyrrylalkyl group, amidoalkyl group or imidoalkyl group, are suitable as photoinitiators for the photopolymerization of ethylenically unsaturated compounds.
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- The chlorination of isobutyrophenone: determination of its pKa value and of the course of the reaction
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Chlorination of isobutyrophenone in alkaline aqueous solution leads to formation of α-hydroxyisobutyrophenone as the first detectable intermediate; a slow subsequent oxidation gives benzoate.From the rates of the initial chlorinations we have been able to determine the pKa value for the ketone as 18.18 +/- 0.50. α-Chloroisobutyrophenone undergoes surprisingly rapid alkaline hydrolysis, kOH = 71.9 +/- 1.5 M-1 s-1.
- Guthrie, J. Peter,Cossar, John
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p. 397 - 403
(2007/10/02)
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- Generation and Reactions of Carbene Bearing Unprotected Hydroxy Groups at α-Position
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Irradiation of 1,1-dimethyl-2-diazo-2-phenylethanol (1a) either in cyclohexane or in hexene produced 1,1-dimethyl-2-oxo-2-phenylethanol (3a), 2,2-dimethyl-3-phenyloxirane (4a), and 3-phenylbutan-2-one (5a), similarly irradiation of (1a) in methanol gave 1,1-dimethyl-2-methoxy-2-phenylethanol (6a) and 1-methoxy-2-methyl-1-phenylpropene (7a) at the expense of (3a) and (5a), all of which were derived from the (1-hydroxy)cyclohexylphenylcarbene (2b) is also described.
- Tomioka, Hideo,Nunome, Yasuo
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p. 1243 - 1244
(2007/10/02)
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- Arene Hydrides, 8. - SET vs. Nucleophilic Attack in Reactions of α-Bromoisobutyrophenone with Carbanions. Fragmentation of the Anion of Tetrahydrobianthracene
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SET is the main reaction pathway between α-bromoisobutyrophenone (1) and the carbanions 7a-j- of diarylmethanes or disubstituted acetonitriles: 7- 7. + e and e + 1 Br- PhCOCMe2. (3).Main secon
- Werry, Juergen,Stamm, Helmut,Sommer, Andreas
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p. 1553 - 1562
(2007/10/02)
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- Process for the preparation of ketones
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Ketones of the formula II STR1 with Ar, R1 and R2 as indicated below, can be hydroxylated, readily and in high yields, in the α-position using tetrahalogenomethanes and alkali metal hydroxides under phase-transfer conditions.
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- A Synthesis of the C6,C11-Dideoxyanthracyclinone Skeleton via Hassall Cyclization and Oxidative Desilylation
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A sequence of regiocontrolled Diels-Alder reactions has been used to prepare 15.Oxygenation of the benzylic silane in the presence of a fluoride source introduces the C7 hydroxyl group (95percent).Further conversion to the nitrile 21 followed by base-induced Hassall cyclization and oxidation gives the anthraquinone 25.Deprotection can be effected, but attempts to prepare 28 result in low yields.The oxygenation can be extended to certain enol silanes, but protodesilylation is a serious side reaction.
- Vedejs, E. V.,Pribish, J. R.
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p. 1593 - 1599
(2007/10/02)
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