cas 5471-51-2, Raspberry ketone | Articles data

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Neurotrophic and anti-neuroinflammatory constituents from the aerial parts of Coriandrum sativum
In the course of our continuing search for biologically active compounds from medicinal sources, we investigated the MeOH extract of the aerial parts of Coriandrum sativum Linn. An extended phytochemical investigation of the aerial parts of C. sativum led to the isolation and identification of seven compounds (1–7) including two new isocoumarin glycosides (1–2) and a new phenolic glycoside (5). The chemical structures of the new compounds (1, 2, and 5) were elucidated by analysis of 1D and 2D NMR (1H and 13C NMR, COSY, HSQC, and HMBC) and HRESIMS data as well as by using chemical methods. All the isolates were evaluated not only for their potential neurotrophic activity by means of induction of nerve growth factor (NGF) in C6 glioma cells but also for production of nitric oxide (NO) levels in lipopolysaccharide (LPS)-activated murine microglia BV-2 cells to assess their anti-neuroinflammatory activity. Compounds 1–3 and 7 were stimulants of NGF release, with levels of NGF stimulated at 127.23 ± 1.89%, 128.22 ± 5.45%, 121.23 ± 6.66%, and 120.94 ± 3.97%, respectively. Furthermore, the aglycones of 1 and 2 (1a and 2a) showed more potent NGF secretion activity and anti-neuroinflammatory effect than did their glycosides (1a: 130.81 ± 5.45% and 2a: 134.44 ± 5.45%).
Cha, Joon Min,Yoon, DaHye,Kim, Sun Yeou,Kim, Chung Sub,Lee, Kang Ro
(2020)
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Stereochemistry of the double bond saturation in the formation in Baker's yeast of 4-(4-hydroxyphenyl)-2-butanone (raspberry ketone)
Yeast extract-mediated reduction of 4-(4-hydroxyphenyl)-but-3-en-2-one 3 to raspberry ketone 1 occurs with transfer β to the carbonyl group of H(R) from NADPH and of an hydrogen atom from the solvent at α position, as indicated by experiments with (4R) and (4S) [4-2H]-NADPH and with deuterated solvent. The same extract converts 3 in 1 in the presence of NADH, but much less efficiently. In this latter case H(S) and not H(R) is transferred from the reduced cofactor to position 4 of 1. Horse liver alcohol dehydrogenase-mediated reduction of 1, bearing deuterium labelling at positions 1, 3 and 4 and obtained from 3 using the whole-cell system in the presence of D2O, gave an S carbinol possessing 0.95 ee, shown by 2H NMR studies onto the diacetate 7 to contain an excess of the (3S,4S) diastereoisomer, thus suggesting a prevalent β re-face,syn addition of hydrogen across the double bond of 3 in the whole-cell mediated conversion into 1.
Fronza, Giovanni,Fuganti, Claudio,Mendozza, Monica,Rallo, Roberta S.,Ottolina, Gianluca,Joulain, Daniel
p. 4041 - 4052
(1996)
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Direct Addition of Grignard Reagents to Aliphatic Carboxylic Acids Enabled by Bulky turbo-Organomagnesium Anilides
The synthesis of ketones through addition of organometallic reagents to aliphatic carboxylic acids is a straightforward strategy that is limited to organolithium reagents. More desirable Grignard reagents can be activated and controlled with a bulky aniline-derived turbo-Hauser base. This operationally simple procedure allows the straightforward preparation of a variety of aliphatic and perfluoroalkyl ketones alike from functionalized alkyl, aryl and heteroaryl Grignard reagents.
Colas, Kilian,Kohlhepp, Stefanie V.,Mendoza, Abraham,V. D. dos Santos, A. Catarina
supporting information

(2022/02/02)

Synthetic method of high-purity raspberry ketone
The invention belongs to the technical field of perfumes and fine chemical engineering. The invention specifically relates to a synthesis method of high-purity raspberry ketone. To the synthesis method, 2 and 6 - di-tert-butyl phenol are used as raw materials, and the butanone or a-hydroxybutanone is subjected to alkylation reaction under the catalysis condition of the acid catalyst 4 - to generate 2 and 6 - b di-tert-butyl -4 -hydroxybenzyl acetone. To the invention, 2, 6 -position occupying-protected phenol 2 and 6 - di-tert-butyl phenol are used as raw materials, and the butanone or 4 -hydroxybutanone alkylation reaction can 100% position in the para position, and the obtained 2 and 6 - di-tert-butyl -4 -hydroxybenzyl acetone. Yield. A tert-butyl process is performed, so that high-yield and high-purity raspberry ketone is obtained. The method is simple in process, short in reaction time, high in product purity, recyclable in reaction byproducts, recyclable in catalyst, low in cost and suitable for industrial production.
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Paragraph 0043-0049

(2021/11/21)

Preparation method of raspberry ketone
The invention relates to a preparation method of raspberry ketone. The preparation method comprises the step of reacting phenol with butanone alcohol under the action of an organic acid catalyst and a crown ether cocatalyst to obtain the target product raspberry ketone. The raspberry ketone prepared by the method is high in yield, the molar yield can reach up to 91.96% (according to the consumption molar number of butanone alcohol), meanwhile, the dosage of the organic acid catalyst in the preparation method is small, the generation of three wastes can be effectively reduced, and the method has great economic benefits and environmental protection benefits.
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Paragraph 0038-0076

(2021/08/07)

8-Hydroxyquinolin-2(1H)-one analogues as potential β2-agonists: Design, synthesis and activity study
β2-Agonists that bind to plasmalemmal β2-adrenoceptors causing cAMP accumulation are widely used as bronchodilators in chronic respiratory diseases. Here, we designed and synthesized a group of 8-hydroxyquinolin-2(1H)-one analogues and studied their β2-agonistic activities with a cellular cAMP assay. Compounds B05 and C08 were identified as potent (EC50 2-agonists among the compounds tested. They behaved as partial β2-agonists in non-overexpressed HEK293 cells, and possessed rapid smooth muscle relaxant actions and long duration of action in isolated guinea pig tracheal strip preparations. In summary, B05 and C08 are β2-agonists with potential applicability in chronic respiratory diseases.
Xing, Gang,Zhi, Zhengxing,Yi, Ce,Zou, Jitian,Jing, Xuefeng,Yiu-Ho Woo, Anthony,Lin, Bin,Pan, Li,Zhang, Yuyang,Cheng, Maosheng
(2021/07/19)

Efficient demethylation of aromatic methyl ethers with HCl in water
A green, efficient and cheap demethylation reaction of aromatic methyl ethers with mineral acid (HCl or H2SO4) as a catalyst in high temperature pressurized water provided the corresponding aromatic alcohols (phenols, catechols, pyrogallols) in high yield. 4-Propylguaiacol was chosen as a model, given the various applications of the 4-propylcatechol reaction product. This demethylation reaction could be easily scaled and biorenewable 4-propylguaiacol from wood and clove oil could also be applied as a feedstock. Greenness of the developed methodversusstate-of-the-art demethylation reactions was assessed by performing a quantitative and qualitative Green Metrics analysis. Versatility of the method was shown on a variety of aromatic methyl ethers containing (biorenewable) substrates, yielding up to 99% of the corresponding aromatic alcohols, in most cases just requiring simple extraction as work-up.
Bomon, Jeroen,Bal, Mathias,Achar, Tapas Kumar,Sergeyev, Sergey,Wu, Xian,Wambacq, Ben,Lemière, Filip,Sels, Bert F.,Maes, Bert U. W.
supporting information
p. 1995 - 2009
(2021/03/26)

Deracemization and Stereoinversion of Alcohols Using Two Mutants of Secondary Alcohol Dehydrogenase from Thermoanaerobacter pseudoethanolicus
We developed a one-pot sequential two-step deracemization approach to chiral alcohols using two mutants of Thermoanaerobacter pseudoethanolicus secondary alcohol dehydrogenase (TeSADH). This approach relies on consecutive non-stereospecific oxidation of alcohols and stereoselective reduction of their prochiral ketones using two mutants of TeSADH with poor and good stereoselectivities, respectively. More specifically, W110G TeSADH enables a non-stereospecific oxidation of alcohol racemates to their corresponding prochiral ketones, followed by W110V TeSADH-catalyzed stereoselective reduction of the resultant ketone intermediates to enantiopure (S)-configured alcohols in up to > 99 percent enantiomeric excess. A heat treatment after the oxidation step was required to avoid the interference of the marginally stereoselective W110G TeSADH in the reduction step; this heat treatment was eliminated by using sol-gel encapsulated W110G TeSADH in the oxidation step. Moreover, this bi-enzymatic approach was implemented in the stereoinversion of (R)-configured alcohols, and (S)-configured alcohols with up to > 99 percent enantiomeric excess were obtained by this Mitsunobu-like stereoinversion reaction.
Hamdan, Samir M.,Musa, Musa M.,Nafiu, Sodiq A.,Takahashi, Etsuko,Takahashi, Masateru
(2020/07/24)

Indigo Formation and Rapid NADPH Consumption Provide Robust Prediction of Raspberry Ketone Synthesis by Engineered Cytochrome P450 BM3
Natural raspberry ketone has a high value in the flavor, fragrance and pharmaceutical industries. Its extraction is costly, justifying the search for biosynthetic routes. We hypothesized that cytochrome P450 BM3 (P450 BM3) could be engineered to catalyze the hydroxylation of 4-phenyl-2-butanone, a naturally sourceable precursor, to raspberry ketone. The synthesis of indigo by variants of P450 BM3 has previously served as a predictor of promiscuous oxidation reactions. To this end, we screened 53 active-site variants of P450 BM3 using orthogonal high-throughput workflows to identify the most streamlined route to all indigo-forming variants. Among the three known and 13 new indigo-forming variants, eight hydroxylated 4-phenyl-2-butanone to raspberry ketone. Previously unreported variant A82Q displayed the highest initial rates and coupling efficiencies in synthesis of indigo and of raspberry ketone. It produced the highest total concentration of raspberry ketone despite producing less total indigo than previously reported variants. Its productivity, although modest, clearly demonstrates the potential for development of a biocatalytic route to raspberry ketone. In addition to validating indigo as a robust predictor of this promiscuous activity, we demonstrate that monitoring rapid NADPH consumption serves as an alternative predictor of a promiscuous reactivity in P450 BM3.
Rousseau, Olivier,Ebert, Maximilian C. C. J. C.,Quaglia, Daniela,Fendri, Ali,Parisien, Adem H.,Besna, Jonathan N.,Iyathurai, Saathanan,Pelletier, Joelle N.
p. 837 - 845
(2019/12/15)

Preparation method of 4-p-hydroxyphenyl-2-butanone
The invention discloses a preparation method of 4-p-hydroxyphenyl-2-butanone. The preparation method comprises the following steps of using anisaldehyde from a natural source as a raw material, preparing to obtain anisalcohol through a reduction reaction, preparing to obtain p-methoxybenzyl chloride through a chlorination reaction, next preparing to obtain 2-acetyl-3-(4-methoxyphenyl)ethyl propionate through a substitution reaction with ethyl acetoacetate from a biomass source, next preparing to obtain 4-(4-methoxyphenyl)-2-butanone through hydrolysis and decarboxylation reactions, and finallypreparing to obtain the 4-p-hydroxyphenyl-2-butanone through a demethylation reaction. The preparation method can be used for realizing the preparation of all-natural carbon-source raspberry ketone,and has the advantages of being simple and direct in route, easy to operate, environmentally friendly and high in yield and the like.
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(2019/02/10)

All-natural carbon source raspberry ketone preparation method
The invention discloses an all-natural carbon source raspberry ketone preparation method, which comprises: carrying out a demethylation reaction on naturally-derived p-anisaldehyde as a raw material to prepare p-hydroxybenzaldehyde, carrying out a Knoevenagel condensation reaction on the p-hydroxybenzaldehyde and ethyl acetoacetate derived from biomass to obtain ethyl (E/Z)-2-acetyl-3-(4-hydroxyphenyl)acrylate, and carrying out hydrogenation, hydrolysis and decarboxylation to prepare the raspberry ketone. According to the present invention, the method can achieve the preparation of the all-natural carbon source raspberry ketone, and has advantages of simple route, easy operation, environmental friendliness, high yield and the like.
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(2019/02/04)

Raspberry ketone reaction device and raspberry ketone continuous preparation method
The invention discloses a raspberry ketone reaction device and a raspberry ketone continuous prepration method. A 4-formyl sodium phenate solution and acetone are taken as raw materials, water is taken as a solvent, and continuous aldehyde ketone condensation reaction is performed in a micro reactor to obtain an aqueous solution of 4-(3-oxo-1-butene) sodium phenolate; an intermediate solution is not separated and is added with a catalyst to continuously react with hydrogen gas in a tubular reactor with a pusher airscrew, so that olefin is selectively reduced to obtain the aqueous solution of raspberry ketone sodium salt, and the aqueous solution is subjected to after-treatment operation such as neutralization and crystallization to obtain raspberry ketone. In a synthesis process, water isonly used as the solvent, so that separating safety of the catalyst is improved, and product selectivity is as high as 99%, and raspberry alcohol generated by excessive reduction is less than 0.2%. the reaction system is free of amplifying effect, has good stability of continuous reaction, has the advantages of simple and convenient operation, short production period, simple production process, less pollution, low energy consumption, and the like, and is suitable for industrialized production.
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Paragraph 0039; 0040; 0050; 0051; 0056; 0057

(2019/01/14)

KETONES AND METHOD FOR MANUFACTURING ANALOG THEREOF
PROBLEM TO BE SOLVED: To provide a technique for efficiently producing ketones by using cellulose after extracting chitin and chitosan extracted from the crustacean or sucrose from the beet in order to effectively using wastes, such as a crustacean or a beat to prepare a solid catalyst. SOLUTION: A method for manufacturing 1-phenyl-3-ketones and an analog (a compound 3) comprises using at least one kind selected from a group consisting of cellulose, chitin and chitosan as a carrier and reacting benzyl alcohols (a compound 1) with ketones (a compound 2) in the presence of a solid catalyst obtained by supporting a group 8-10 transition metal and a base. The following chemical formula 1 is shown. SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
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Paragraph 0101; 0104-0106

(2019/04/05)

Chemoselective transfer hydrogenation of Α,Β-unsaturated carbonyls catalyzed by a reusable supported Pd nanoparticles on biomass-derived carbon
We herein report highly chemoselective transfer hydrogenation of α,β-unsaturated carbonyl compounds to saturated carbonyls with formic acid as a hydrogen donor over a stable and recyclable heterogeneous Pd nanoparticles (NPs) on N,O-dual doped hierarchical porous biomass-derived carbon. The synergistic effect between Pd NPs and incorporated heteroatoms on carbon plays a critical role on promoting the reaction efficiency. A series of α,β-aromatic and aliphatic unsaturated carbonyl compounds was selectively reduced to their corresponding saturated carbonyls in up to 97% isolated yields with good tolerance of various functional groups. In addition, the catalyst can be successively reused for at least 6 times without significant loss in reaction efficiency.
Song, Tao,Duan, Yanan,Yang, Yong
p. 80 - 85
(2019/01/03)

Chemoselective Hydrogenation of α,β-Unsaturated Carbonyls Catalyzed by Biomass-Derived Cobalt Nanoparticles in Water
Herein, we report highly chemoselective hydrogenation of α,β-unsaturated carbonyls to saturated carbonyls catalyzed by cobalt nanoparticles supported on the biomass-derived carbon from bamboo shoots with molecular hydrogen in water, which is the first prototype using a heterogeneous non-noble metal catalyst for such organic transformation as far as we know. The optimal cobalt nanocatalyst, CoOx@NC-800, manifested remarkable activity and selectivity for hydrogenation of C=C in α,β-unsaturated carbonyls under mild conditions. A broad set of α,β-aromatic and aliphatic unsaturated carbonyls were selectively reduced to their corresponding saturated carbonyls in up to 99 % yields with good tolerance of various functional groups. Meanwhile, a new straightforward one-pot cascade synthesis of saturated carbonyls was realized with high activity and selectivity via the cross-aldol condensation of ketones with aldehydes followed by selective hydrogenation. More importantly, this one-pot strategy is applicable for the expedient synthesis of Loureirin A, a versatile bioactive and medicinal molecule, from readily available starting materials, further highlighting the practical utility of the catalyst. In addition, the catalyst can be easily separated for successive reuses without significant loss in both activity and selectivity.
Song, Tao,Ma, Zhiming,Yang, Yong
p. 1313 - 1319
(2019/01/25)

Two efficient pathways for the synthesis of aryl ketones catalyzed by phosphorus-free palladium catalysts
Allylic alcohols, 1-buten-3-ol, 1-penten-3-ol and 1-octen-3-ol, reacted with aryl iodides (iodotoluene, 4-iodotoluene, 4-iodophenol and 4-iodanisole) under Heck reaction conditions to form corresponding saturated aryl ketones in one step. The same products were obtained in a two-step tandem reaction consisted of the Heck coupling of allylic alcohols with aryl iodides, followed by hydrogenation. Reactions were catalyzed by phosphorus-free palladium precursors modified with the menthol-substituted imidazolium chlorides. Formation of crystalline palladium nanoparticles, of the diameter up to 65 nm, in the reaction mixture was evidenced by TEM.
Wirwis,Feder-Kubis,Trzeciak
p. 61 - 72
(2018/01/05)

Synthesis of raspberry ketone via Friedel-Crafts alkylation reaction catalyzed by sulfonic acid-functional ionic liquids
Phenol and butanolone catalyzed by different SO3H-functionalized ionic liquids (ILs) for synthesis of raspberry ketone (RK) had been investigated. The influences of different ionic liquids, reaction time, reaction temperature, reactant ratio, t
Wang, Wang,He, Zhenzhen,Li, Conghao,You, Zhixiang,Guo, Hongyun
p. 56 - 61
(2018/02/09)

HYDROSILANE/LEWIS ACID ADDUCT, PARTICULARLY ALUMINUM, IRON, AND ZINC, METHOD FOR PREPARING SAME, AND USE OF SAID SAME IN REACTIONS FOR REDUCING CARBONYL DERIVATIVES
Disclosed is an adduct between a Lewis acid, preferably aluminum trichloride, iron trichloride, or zinc dichloride, and a hydrosilane;—a method for preparing same; and a method for for reducing, particularly, an aldehyde, a ketone, an α,β-unsaturated ketone, an imine, or an α,β-unsaturated imine.
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Paragraph 0181; 0182; 0183

(2018/02/28)

Method for preparing raspberry ketone under catalysis of multi-sulfonic functionalized ionic liquid
The invention discloses a method for preparing raspberry ketone under the catalysis of multi-sulfonic functionalized ionic liquid. According to the method, phenol and methyl vinyl ketone are used as raw materials and the multi-sulfonic functionalized ionic liquid is used as a catalyst for selective catalytic synthesis of raspberry ketone. The ionic catalyst has the advantages of high acid value, low synthesis cost, good catalysis efficiency and reaction activity at room temperature compared with conventional ionic catalysts.
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Paragraph 0027; 0028; 0029; 0030; 0031; 0032; 0033-0038

(2017/08/30)

Simple Synthesis of Phytochemicals by Heterogeneous Pd- and Ir-Catalyzed Hydrogen-Borrowing C–C Bond Formation
Chitin-supported palladium and iridium catalysts (i.e., Pd/chitin, Ir/chitin) successfully promote the hydrogen borrowing C–C bond formation reaction to afford phytochemicals and aroma compounds in excellent yields.
Hori, Yoji,Suruga, Chiharu,Akabayashi, Yuta,Ishikawa, Tomoka,Saito, Marina,Myoda, Takao,Toeda, Kazuki,Maeda, Yuna,Yoshida, Yutaka
p. 7295 - 7299
(2018/01/02)

Structure-Activity Relationships of 6- and 8-Gingerol Analogs as Anti-Biofilm Agents
Pseudomonas aeruginosa is a causative agent of chronic infections in immunocompromised patients. Disruption of quorum sensing circuits is an attractive strategy for treating diseases associated with P. aeruginosa infection. In this study, we designed and synthesized a series of gingerol analogs targeting LasR, a master regulator of quorum sensing networks in P. aeruginosa. Structure-activity relationship studies showed that a hydrogen-bonding interaction in the head section, stereochemistry and rotational rigidity in the middle section, and optimal alkyl chain length in the tail section are important factors for the enhancement of LasR-binding affinity and for the inhibition of biofilm formation. The most potent compound 41, an analog of (R)-8-gingerol with restricted rotation, showed stronger LasR-binding affinity and inhibition of biofilm formation than the known LasR antagonist (S)-6-gingerol. This new LasR antagonist can be used as an early lead compound for the development of anti-biofilm agents to treat P. aeruginosa infections.
Choi, Hyunsuk,Ham, So-Young,Cha, Eunji,Shin, Yujin,Kim, Han-Shin,Bang, Jeong Kyu,Son, Sang-Hyun,Park, Hee-Deung,Byun, Youngjoo
p. 9821 - 9837
(2017/12/26)

Selective hydrogenation of conjugated unsaturated ketones containing a hydroxyaryl substituent in the β-position
A high selectivity was achieved in the Ni2B-catalyzed hydrogenation of α,β-unsaturated ketones containing a hydroxyaryl (phenolic) substituent in the β-position. The developed hydrogenation procedure was used to synthesize natural compounds of the phenylpropane series and their structural analogs.
Kovalenko,Pratsko
p. 24 - 28
(2017/03/16)

H-type zeolite-catalyzed 1,4-addition of benzene derivatives to labile acrolein
The 1,4-addition of benzene derivatives to acrolein is a straightforward way to synthesize 3-arylpropanals. A survey of acid catalysts for the 1,4-addition of methoxy-substituted benzenes to acrolein revealed that H-Beta and H-Y were the most suitable catalysts. We hypothesized three side-reactions: (1) the double 1,4-addition of acrolein to the starting benzene derivatives, (2) the Friedel-Crafts-type alkylation to the desired product, and (3) the self-polymerization of acrolein. The type (3) side-reaction was inhibited by two different methods which kept the concentration of acrolein low in the reaction mixture or in the zeolite pores. First, acrolein monomers were in situ generated through the gradual monomerization of an acrolein cyclic trimer. Second, using a reaction solvent lowered the acrolein concentration in the zeolite pores due to the competitive adsorption. We discovered that the content of monomeric acrolein in a solvent was closely related to the polarity of the solvent. Actually, both methods improved the yields for the 1,4-additions of 1,3-dimethoxybenzene to acrolein. Other electron-rich benzene derivatives, such as phenol and N, N-dimethylaniline, were also applicable to the 1,4-addition reactions.
Hayashi, Daijiro,Narisawa, Tomoyuki,Masui, Yoichi,Onaka, Makoto
p. 460 - 471
(2016/04/26)

Decarboxylative Csp3-Csp3 coupling for benzylation of unstable ketone enolates: Synthesis of: P -(acylethyl)phenols
A new decarboxylative Csp3-Csp3 coupling approach for the benzylation of ketone enolates has been developed. A variety of raspberry ketone derivatives were conveniently synthesized in good to excellent yields under mild conditions. A crossover reaction shed light on the mechanism of this tandem reaction.
Wang, Sasa,Chen, Xinzheng,Ao, Qiaoqiao,Wang, Huifei,Zhai, Hongbin
supporting information
p. 9454 - 9457
(2016/07/29)

Identification of a new curcumin synthase from ginger and construction of a curcuminoid-producing unnatural fusion protein diketide-CoA synthase::curcumin synthase
The biosynthesis and metabolic engineering of curcuminoids received considerable attention for their important pharmaceutical properties. In the present study, a new curcumin synthase (ZoCURS) was identified from ginger (Zingiber officinale). Notably, ZoCURS efficiently accepts 3-(4-hydroxyphenyl)propionyl-CoA to produce tetrahydrobisdemethoxycurcumin, which would be meaningful to further understand the biosynthesis of curcuminoids in ginger. In addition, a curcuminoid-producing unnatural fusion protein diketide-CoA synthase::curcumin synthase (DCS::CURS) was constructed. Comparing to ZoCURS, DCS::CURS indicated similar substrate specificities and catalytic potentials to catalyze the formation of various curcuminoids, however, the yield of curcuminoids produced by DCS::CURS was obviously increased, which would be useful for metabolic engineering of pharmaceutically important curcuminoid analogs, particularly including asymmetric dihydrocurcuminoids such as 3-(4-hydroxyphenyl)propionyl-feruloylmethane, 3-(4-hydroxyphenyl)propionyl-p-coumaroylmethane, and 3-(4-hydroxyphenyl)propionyl-cinnamoylmethane.
Zhang, Le,Gao, Bowen,Wang, Xiaohui,Zhang, Zhongxiu,Liu, Xiao,Wang, Juan,Mo, Ting,Liu, Yuyu,Shi, Shepo,Tu, Pengfei
p. 12519 - 12524
(2016/02/12)

Deracemization of Secondary Alcohols by using a Single Alcohol Dehydrogenase
We developed a single-enzyme-mediated two-step approach for deracemization of secondary alcohols. A single mutant of Thermoanaerobacter ethanolicus secondary alcohol dehydrogenase enables the nonstereoselective oxidation of racemic alcohols to ketones, followed by a stereoselective reduction process. Varying the amounts of acetone and 2-propanol cosubstrates controls the stereoselectivities of the consecutive oxidation and reduction reactions, respectively. We used one enzyme to accomplish the deracemization of secondary alcohols with up to >99 % ee and >99.5 % recovery in one pot and without the need to isolate the prochiral ketone intermediate.
Karume, Ibrahim,Takahashi, Masateru,Hamdan, Samir M.,Musa, Musa M.
p. 1459 - 1463
(2016/05/02)

A Hantzsch Amido Dihydropyridine as a Transfer Hydrogenation Reagent for α,β-Unsaturated Ketones
An improved synthesis of the bis-methylamido Hantzsch dihydropyridine is described. The Hantzsch amide is demonstrated to be an effective transfer hydrogenation reagent using α,β-unsaturated ketones as the test case. Unreacted Hantzsch amide and the bis-methylamidopyridine byproduct are effectively removed by extraction in contrast to the commonly used Hantzsch diethyl ester. Several examples are given with the reaction being more effective for conjugated aromatic substrates than for aliphatics.
Van Arman, Scott A.,Zimmet, Austin J.,Murray, Ian E.
p. 3528 - 3532
(2016/05/24)

A process for synthesizing of raspberry ketone
The invention discloses a synthesis process of raspberry ketone. The synthesis process comprises the following steps: (1) synthesizing butanone alcohol in the presence of a catalyst namely NaOH by adopting a theta-ring stainless steel packing fixed bed reactor and taking formaldehyde and acetone as raw materials; (2) synthesizing raspberry ketone in the presence of a catalyst namely ion exchange resin D218 by taking butanone alcohol and phenol as raw materials and adopting a fluidized bed reactor. According to the synthesis process disclosed by the invention, butanone alcohol is synthesized in the presence of the catalyst namely NaOH by taking acetone and formaldehyde as raw materials, so that the synthesis process has the advantages of low cost, short reaction time, simplicity and convenience in operation, less side reactions, high yield and the like; and raspberry ketone is synthesized in the presence of the catalyst namely the strongly acid cation exchange resin D218, the equipment corrosivity during the process is small, the after treatment is simple, and the reuse rate of the catalysts is high. The synthesis process is a novel efficient and environment-friendly production method.
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Paragraph 0043

(2017/01/09)

Preparation of a raspberry ketone precursor in the presence of rare earth oxide catalysts
The raspberry precursor 4-(4-hydroxyphenyl)-but-3-ene-2-one which afterwards undergoes a catalytic hydrogenation to produce raspberry ketone was synthesized by aldol condensation of acetone and 4-hydroxybenzaldehyde over rare earth oxides as basic catalysts and supported rare earth oxides as acid-base bifunctional catalysts. Thereby, several rare earth metal oxides were tested in their neat form as well as supported on carriers with high surface areas such as alumina, titania, tetragonal zirconia and charcoal. The catalysts were characterized by XRD, BET, NH3/CO2-TPD and pyridine-FTIR. All experiments were carried out batch wise in 75 ml autoclaves adjusting molar ratios of acetone and 4-hydroxybenz-aldehyde from 12:1 to 4:1, temperature range from 80 to 200 °C and autogeneous pressures from 1 to 25 bar. It could also be realized, that titania and alumina are no inert materials, but also highly active catalysts for this reaction. An experimental design program was used to optimize the reaction conditions as well as the conversion and selectivity. In addition the reaction was carried out in a fixed bed plug flow reactor to determine stability and robustness of the catalyst. The quality/contaminations of the starting material have a strong influence on the catalytic performance.
Hoelderich, Wolfgang F.,Ritzerfeld, Verena
p. 654 - 663
(2015/10/05)

CHEMOSELECTIVE ENRICHMENT FOR COMPOUND ISOLATION
Chemoselective isolation of aliphatic hydroxyl group-containing and aromatic hydroxyl group-containing compounds is accomplished via formation of polymeric siloxyl ethers. Chemoselective release of aliphatic hydroxyl group-containing and aromatic hydroxyl group-containing compounds from polymeric siloxyl reagents is described.
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Paragraph 0284; 0289

(2014/05/07)

Synthesis of raspberry and ginger ketones by nickel boride-catalyzed hydrogenation of 4-arylbut-3-en-2-ones
Raspberry and ginger ketones have been synthesized in good yield by the hydrogenation of the corresponding unsaturated precursors 4-(4′- hydroxyphenyl)but-3-en-2-one and 4-(4′-hydroxy-3′-methoxyphenyl)but- 3-en-2-one, respectively, using a freshly prepared suspension of nickel boride in methanol as catalyst.
Bandarenko, Mikhail,Kovalenko, Vitaly
p. 885 - 888
(2014/11/08)

Highly chemo- and regioselective reaction of hydroxybenzenes in acidic ionic liquid
Highly chemo- and regioselective reaction of hydroxybenzenes with α,β-unsaturated compounds in acidic ionic liquid l-butyl-3- methylimidazolium hydrogen sulphate ([BMIM]HSO4) was reported for the first time. A series of oxa-Michael adducts and Friedel-Crafts alkylated products were synthesized with good yields. The acidic ionic liquid could be easily recycled for at least 5 times with only minor loss in activity.
Guo, Hui,Zhuang, Yu Wei,Cao, Jian,Zhang, Guo Bao
p. 2594 - 2596
(2013/10/22)

Taming of a superbase for selective phenol desilylation and natural product isolation
Hydroxyl moieties are highly prevalent in natural products. We previously reported a chemoselective strategy for enrichment of hydroxyl-functionalized molecules by formation of a silyl ether bond to a resin. To generate smaller pools of molecules for analysis, we developed cleavage conditions to promote stepwise release of phenolic silyl ethers followed by aliphatic silyl ethers with a "tamed" version of the superbase 1,1,3,3-tetramethylguanadine. We demonstrate this as a general strategy for selective deprotection of phenolic silyl ethers under neutral conditions at room temperature.
Trader, Darci J.,Carlson, Erin E.
p. 7349 - 7355
(2013/08/23)

Transfer hydrogenations of alkenes with formate on Pd/C: Synthesis of dihydrocinchona alkaloids
Protocols for preparative (1-80 gram scale) transfer hydrogenations of alkenes over a palladium on carbon catalyst using formic acid/ammonium formate as hydrogen donor are presented. Cinchona alkaloids have been converted to their dihydro derivatives in >94% yield. Georg Thieme Verlag Stuttgart - New York.
Wu, Haotian,Hintermann, Lukas
p. 888 - 892
(2013/05/09)

Escherichia coli/ADH-A: An all-inclusive catalyst for the selective biooxidation and deracemisation of secondary alcohols
The nicotinamide adenine dinucleotide regeneration system present in Escherichia coli cells was exploited for the oxidation and deracemisation of secondary alcohols with the overexpressed alcohol dehydrogenase from Rhodococcus ruber DSM 44541 (E. coli/ADH-A). Thus, various racemic alcohols were selectively oxidised with lyophilised or resting E. coli/ADH-A cells without need for an external cofactor or co-substrate. The addition of these substrates to the E. coli/ADH-A cells in buffer afforded the corresponding ketones and the remaining enantioenriched (R)-alcohols. This methodology was used for the desymmetrisation of a meso-diol and for the synthesis of the highly valuable raspberry ketone. Moreover, a biocatalytic concurrent process was developed with the resting cells of E. coli/ADH-A, ADH from Lactobacillus brevis, and glucose dehydrogenase for the deracemisation of various secondary alcohols, which afforded the desired enantiopure alcohols in more than 99 % ee starting from the racemic mixture. The reaction time of deracemisation of 1-phenylethanol was estimated to be less than 30 min. The stereoinversion of (S)-1-phenylethanol to its pure (R)-enantiomer was also achieved, which provided a biocatalytic alternative to the chemical Mitsunobu inversion reaction. An integrated recycling system: A nicotinamide adenine dinucleotide regeneration system present in Escherichia coli cells is exploited for the oxidation of secondary alcohols with E. coli/alcohol dehydrogenase (ADH-A). Racemic alcohols are oxidized selectively without need for an external cofactor or cosubstrate, which affords the remaining enantioenriched (R)-alcohols. Deracemization, desymmetrization, and stereoinversion processes are developed, which leads to optically pure high value-added compounds. Copyright
Paul, Caroline E.,Lavandera, Ivan,Gotor-Fernandez, Vicente,Kroutil, Wolfgang,Gotor, Vicente
p. 3875 - 3881
(2014/01/06)

A scalable two-step continuous flow synthesis of nabumetone and related 4-aryl-2-butanones
Three different continuous flow strategies for the generation of important 4-aryl-2-butanone derivatives including the anti-inflammatory drug nabumetone [4-(6-methoxy-2-naphthalenyl)-2-butanone] and the aroma compounds raspberry ketone [4-(4-hydroxyphenyl)-2-butanone] and its methyl ether [4-(4-methoxyphenyl)-2-butanone] were evaluated. All three protocols involve the initial preparation of the corresponding 4-aryl-3-buten-2-ones via Mizoroki-Heck, Wittig, or aldol strategies, which is then followed by selective hydrogenation of the C=C double bond to the desired 4-aryl-2-butanones. The synthetic routes to 4-aryl-3-buten-2-ones were first optimized/intensified on small scale to reaction times of 1-10 min using batch microwave heating technology and then translated to a scalable continuous flow process employing commercially available stainless steel capillary tube reactors. For the synthesis of 4-(4-methoxyphenyl)-3-buten-2-one a further scale-up using a custom-built mesofluidic mini-plant flow system capable of processing several liters per hour was designed to further expand the scale of the process. The final hydrogenation step was performed using a fixed-bed continuous flow hydrogenator employing Ra/Ni as a catalyst.
Viviano, Monica,Glasnov, Toma N.,Reichart, Benedik,Tekautz, Guenter,Kappe, C. Oliver
p. 858 - 870
(2012/06/30)

First bovine serum albumin-promoted synthesis of enones, cinnamic acids and coumarins in ionic liquid: An insight into the role of protein impurities in porcine pancreas lipase for olefinic bond formation
During studies on exploiting the catalytic promiscuity of crude porcine pancreas lipase (PPL) in ionic liquid for C=C bond formations, bovine serum albumin (BSA) was found to be competing for these reactions. After a detailed investigation, we establish that these transformations are possible by unspecific protein catalysis rather than catalytic promiscuity of "PPL" - a first insight into the role of protein impurities in crude enzyme. Thus, a novel and highly efficient, environmentally friendly approach involving synergistic catalysis by bovine serum albumin-1-butyl-3- methylimidazolium bromide (BSA-[bmim]Br) has been developed for the synthesis of (E)-α,β-unsaturated compounds including a one-pot cascade synthesis of cinnamic acids and coumarins via aldol, Knoevenagel and Knoevenagel-Doebner condensations.
Sharma, Nandini,Sharma, Upendra K.,Kumar, Rajesh,Katoch, Nidhi,Kumar, Rakesh,Sinha, Arun K.
p. 871 - 878
(2011/06/19)

Process for the Preparation of 4-(4-hydroxyphenyl)butan-2-one Using Solid Acid Clay Catalyst
Solid acid catalyst such as acid activated-Montmorillonite clay composite has been developed by modifying the Na-Montmorillonite clay with acid (HCl) treatment for different periods such as 5 minutes to about 4 hours and activating at about 12O° C. for about 2 hours. Friedel Crafts alkylation reaction between phenol and 4-hydroxybutan-2-one in presence of the acid activated Montmorillonite clay catalysts exhibiting layered clay structures (basal spacing d001 ranging from about 10 to 13.5 ?), high surface area (250-400 m2/g), highly porous {micropores in the range 5 to 15 ? and mesopores in the range 30 to 80 ?}, average pore volume 0.2 to 0.65 cc/g, and surface acidity in the range 0.4-0.6 mmol/g; under constant stirring and at pressure of 1-15 bar, temperature 100-15O° C. for a period of about 12-24 hours produces 4-(4-hydroxyphenyl)butan-2-one (Raspberry ketone) exhibiting conversion about 35-55% and high selectivity in the range 75-81%.
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(2011/10/31)

Morpholinium trifluoroacetate-catalyzed aldol condensation of acetone with both aromatic and aliphatic aldehydes
We report a highly efficient, general and practical method for the aldol condensation of acetone with aromatic and aliphatic aldehydes, using morpholinium trifluoroacetate as a catalyst.
Zumbansen, Kristina,Doehring, Arno,List, Benjamin
experimental part
p. 1135 - 1136
(2010/09/05)

Protection-, salt-, and metal-free syntheses of [n]-shogaols by use of dimethylammonium dimethyl carbamate (DIMCARB) without protecting groups
Shogaols, the pungent principle of ginger, exhibit interesting bioactivities. Practical preparation of shogaols is highly desired. Here we report the protection/deprotection-, salt-, and metalfree synthesis of shogaol in three steps by use of dimethylammonium dimethyl carbamate (DIMCARB), in which DIMCARB smoothly promoted Mannich-type condensation of the ketone donor with the aldehyde acceptor through the iminium cation intermediate. Georg Thieme Verlag Stuttgart.
Mase, Nobuyuki,Kitagawa, Norihiko,Takabe, Kunihiko
scheme or table
p. 93 - 96
(2010/07/16)

Reduction of solid-supported olefins and alkynes
(Chemical Equation Presented) The reduction of carbon-carbonmultiple bonds in alkynes and olefins supported on a polystyrene resin has been investigated. Homogeneous catalysis by titanocene reagents is effective for the stereoselective preparation of cis-
Dickson, David P.,Toh, Christine,Lunda, Menaka,Yermolina, Maria V.,Wardrop, Duncan J.,Landrie, Chad L.
supporting information; experimental part
p. 9535 - 9538
(2010/03/04)

Arylation of allyl alcohols in organic and aqueous media catalyzed by oxime-derived palladacycles: Synthesis of β-arylated carbonyl compounds
A 4-hydroxyacetophenone oxime-derived palladacycle catalyzes the Mizoroki-Heck reaction of allyl alcohols with aryl iodides, bromides, and chlorides in aqueous and organic solvents. The reaction takes place in the presence of dicyclohexylmethylamine or cesium carbonate as bases, the addition of tetrabutylammonium bromide (TBAB) as additive for aryl bromides and chlorides being necessary. Under these reaction conditions, β-arylated aldehydes and ketones are mainly obtained using a rather low loading of palladium (0.1-1 mol%). Similar catalytic activity is shown by a Kaiser oxime resin-derived palladacycle, which allows one to perform recycling and reusing experiments with low Pd leaching. The high regio- and chemoselectivity observed supported that these palladacycles, working as a source of Pd(0) species, operates mainly through a neutral mechanism. This methodology has been applied to the synthesis of important β-arylated carbonyl compounds, such as 4-phenylbutan-2-one, 4-(4-hydroxyphenyl)butan-2-one, dihydrochalcones, the anti-inflamatory nabumetone, and the fragance β-lilial. γ-Arylation is observed in the reactions of allyl alcohol and but-3-en-2-ol with 2-iodoaniline giving mainly the corresponding quinolines. The same tendency is observed in the case of 1,1-dimethylallyl alcohol affording either γ-arylated alcohols or (E)-1-arylisoprenes.
Alacid, Emilio,Najera, Carmen
p. 2572 - 2584
(2008/09/19)

A chemoselective hydrogenation of the olefinic bond of α,β- unsaturated carbonyl compounds in aqueous medium under microwave irradiation
A microwave-assisted mild and ecofriendly catalytic transfer hydrogenation process was developed to reduce various α,β-unsaturated carbonyl compounds into the corresponding saturated carbonyl compounds in the presence of silica-supported palladium chloride as catalyst and a combination of MeOH/HCOOH/H2O (1:2:3) as hydrogen source within 22-55 minutes in moderate to excellent yields with 100% chemoselectivity.
Sharma, Anuj,Kumar, Vinod,Sinha, Arun K.
p. 354 - 360
(2007/10/03)

Benzoyl 2-methyl indoles as selective PPARγ modulators
A series of selective PPARγ modulators (SPPARγMs) and their development from hPPARγ active screening leads 1 and 2 is described. SPPARγM 24 displayed robust anti-diabetic activity with an improved therapeutic window in comparison to a PPARγ full agonist in a rodent efficacy model. Routine screening for human PPAR ligands yielded compounds 1 and 2, both of which were sub-micromolar hPPARγ agonists. Synthetic modifications of these leads led to a series of potent substituted 3-benzyl-2-methyl indoles, a subset of which were noted to be selective PPARγ modulators (SPPARγMs). SPPARγM 24 displayed robust anti-diabetic activity with an improved therapeutic window in comparison to a PPARγ full agonist in a rodent efficacy model.
Acton III, John J.,Black, Regina M.,Jones, A. Brian,Moller, David E.,Colwell, Lawrence,Doebber, Thomas W.,MacNaul, Karen L.,Berger, Joel,Wood, Harold B.
p. 357 - 362
(2007/10/03)

Arylation of allylic alcohols in ionic liquids catalysed by a Pd-benzothiazole carbene complex
The reaction of aryl bromides with allylic alcohols catalysed by a Pd-benzothiazole carbene complex, in tetrabutylammonium bromide as solvent, leads principally to β-arylated carbonyl compounds. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
Calo, Vincenzo,Nacci, Angelo,Monopoli, Antonio,Spinelli, Michele
p. 1382 - 1385
(2007/10/03)

Serine carbonates
Serine carbonates of formula I are precursors for organoleptic compounds, masking agents and antimicrobial agents. Further they are alternative substrates for malodor producing enzymes. The symbols in formula I are defined in claim 1.
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(2008/06/13)

Efficient production of raspberry ketone via 'green' biocatalytic oxidation
For the development of a 'green' oxidation method, the transformation of 4-(p-hydroxyphenyl)butan-2-ol (rhododendrol) into 4-(p-hydroxyphenyl) butan-2-one (raspberry ketone) was used as a model reaction. Different lyophilized cells of Rhodococcus spp. have been screened for their ability to perform the desired oxidation. Rhodococcus equi IFO 3730 and R. ruber DSM 44541 were able to use acetone as a hydrogen acceptor in a hydrogen transfer-like process. The oxidation can be performed at substrate concentrations up to 500 g/L.
Kosjek, Birgit,Stampfer, Wolfgang,Van Deursen, Ruud,Faber, Kurt,Kroutil, Wolfgang
p. 9517 - 9521
(2007/10/03)

Compounds having protected hydroxy groups
The present invention relates to compounds with protected hydroxy groups of formula (I) These compounds are precursors for organoleptic agents, such as fragrances, and masking agents and for antimicrobial agents. When activated, the compounds of formula (I) are cleaved and form one or more organoleptic and/or antimicrobial compounds.
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(2008/06/13)

Compounds having protected hydroxy groups
The present invention relates to compounds with protected hydroxy groups of formula (I) These compounds are precursors for organoleptic agents, such as fragrances, and masking agents and for antimicrobial agents. When activated, the compounds of formula (I) are cleaved and form one or more organoleptic and/or antimicrobial compounds.
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(2008/06/13)

Precursors for fragrant ketones and fragrant aldehydes
The present invention refers to fragrance precursors of formula I for a fragrant ketone of formula II and one or more fragrant aldehydes or ketones of formula III and IV, These fragrance precursors are useful in perfumery, especially in the fine and functional perfumery.
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(2008/06/13)

Beta-ketoester compounds
The beta-ketoesters of formula I are useful as precursors for organoleptic compounds, especially for flavors, fragrances and masking agents and antimicrobial compounds.
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(2008/06/13)