- Photoreduction of Cyclic α-Fluoroketones
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Irradiation of the α-fluoroketones 1a and 6a in i-PrOH selectively affords the parent ketone 1b and 6b, respectively.It is concluded that in this solvent heterolytic C-F bond cleavage of the radical -formed by electron transfer to the excited fluoroketone- is a faster process than the subsequent protonation by the cation radical of the solvent.In cyclohexane 1b and 6b are only formed a minor amounts, the fluorinated RH-reduction product 4 now being the major product from 1a.In non-reducing solvents as t-BuOH or benzene 2-fluorocyclohexanone (1a) exhibits a similar behavior as cyclohexanone (1b) on excitation.The quantum yields for α-cleavage are alike for both compounds, but oxetane formation with 2-methylpropene as olefinic component occurs much more readily with 1a than with 1b.
- Reinholdt, Karin,Margaretha, Paul
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- Photoannulation of 4,4-dimethylcyclohex-2-en-1-one to 1,1-diphenylethylene
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The photoannulation of 4,4-dimethylcyclohex-2-en-1-one (DMC) to 1,1-diphenylethylene (DPE) results in the [2+2] formation of cyclobutanes exhibiting regio- and stereoselectivity. Additionally, regio- and stereoisomers of substituted octahydrophenanthrenes are produced. Formally, these are derived from alpha-ortho coupling of a 1,4-biradical, followed by rearomatization. From laser flash photolysis experiments, we conclude that the temporal absorbance profile observed following excitation of DMC in the presence of DPE is a composite of multiple triplet state transients that includes triplet state 1,1-diphenylethylene and likely includes a triplet state 1,4-biradical. This analysis of the transient data reveals energy transfer and product forming interactions between 3DMC and ground-state DPE. The present work renders our earlier interpretation [J. Am. Chem. Soc. 1996, 118, 8741],1 that the transient observed in this system was a 3DMC-DPE exciplex, unnecessary and unlikely.
- Caldwell, Richard A.,Constien, Ralf,Kriel, Bryan G.
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- Photochemical Rduction of 2-Bromo-4,4-dimethyl-2-cyclohexenone
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The photochemical behaviour of 2-Bromo-4,4-dimethyl-2-cyclohexenone (1) was studied in 2-propanol and cyclohexane.In both solvents (n-?*)-excitation followed by intersystem crossing leads to population of a low-lying triplet (T1) state, which can be quenched by 1,3-cyclohexadiene but does not undergo chemical transformation efficiently, (?-?*)-Excitation affords 4,4-dimethyl-2-cyclohexenone (2) as the only product.While in 2-propanol 2 is formed in 60percent from the S2-state and in 40percent from the T2-state, in cyclohexane reduction occurs exclusively from this upper triplet state.The T2-state can also be populated via energy transfer using acetonee or benzene as senzitizer.The mechanistic dissimilarities for the reduction of excited 1 in either 2-propanol or cyclohexane are discussed.
- Hombrecher, Hermann,Margaretha, Paul
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- Synthesis of novel ent-kaurane-type diterpenoid derivatives effective for highly aggressive tumor cells
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We have designed and synthesized 6 ent-Kaurane-type diterpenoid derivatives containing α,β-unsaturated ketone moieties. In vitro, activity was evaluated against three human tumor cell lines and a rat myogenic cell line (HepG2, NSCLC-H292, SNU-1040, L6) by MTT assay. All the tested compounds exhibited comparable or higher activity than DDP and eriocalyxin B. Compounds 16, 17 and 18 are promising anti-tumor leads due to their cytotoxic potencies and higher selectivity, with SI values of 161.06, 47.80 and 128.20, respectively.
- Hu, Yu,Li, Xiao-Nian,Ma, Ze-Jin,Puno, Pema-Tenzin,Zhao, Yong,Zhao, Yan,Xiao, Ye-Zhi,Zhang, Wei,Liu, Jing-Ping
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- Platinum-Catalyzed α,β-Desaturation of Cyclic Ketones through Direct Metal–Enolate Formation
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The development of a platinum-catalyzed desaturation of cyclic ketones to their conjugated α,β-unsaturated counterparts is reported in this full article. A unique diene-platinum complex was identified to be an efficient catalyst, which enables direct metal-enolate formation. The reaction operates under mild conditions without using strong bases or acids. Good to excellent yields can be achieved for diverse and complex scaffolds. A wide range of functional groups, including those sensitive to acids, bases/nucleophiles, or palladium species, are tolerated, which represents a distinct feature from other known desaturation methods. Mechanistically, this platinum catalysis exhibits a fast and reversible α-deprotonation followed by a rate-determining β-hydrogen elimination process, which is different from the prior Pd-catalyzed desaturation method. Promising preliminary enantioselective desaturation using a chiral-diene-platinum complex has also been obtained.
- Chen, Ming,Dong, Guangbin
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supporting information
p. 7956 - 7961
(2021/03/01)
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- Bidentate Nitrogen-Ligated I(V) Reagents, Bi(N)-HVIs: Preparation, Stability, Structure, and Reactivity
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Hypervalent iodine(V) reagents are a powerful class of organic oxidants. While the use of I(V) compounds Dess-Martin periodinane and IBX is widespread, this reagent class has long been plagued by issues of solubility and stability. Extensive effort has been made for derivatizing these scaffolds to modulate reactivity and physical properties but considerable room for innovation still exists. Herein, we describe the preparation, thermal stability, optimized geometries, and synthetic utility of an emerging class of I(V) reagents, Bi(N)-HVIs, possessing datively bound bidentate nitrogen ligands on the iodine center. Bi(N)-HVIs display favorable safety profiles, improved solubility, and comparable to superior oxidative reactivity relative to common I(V) reagents. The highly modular synthesis and in situ generation of Bi(N)-HVIs provides a novel and convenient screening platform for I(V) reagent and reaction development.
- Xiao, Xiao,Roth, Jessica M.,Greenwood, Nathaniel S.,Velopolcek, Maria K.,Aguirre, Jordan,Jalali, Mona,Ariafard, Alireza,Wengryniuk, Sarah E.
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p. 6566 - 6576
(2021/05/06)
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- Strong and Confined Acids Control Five Stereogenic Centers in Catalytic Asymmetric Diels–Alder Reactions of Cyclohexadienones with Cyclopentadiene
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We describe a highly enantioselective Diels–Alder reaction of cross-conjugated cyclohexadienones with cyclopentadiene, in which five stereocenters are effectively controlled by a strongly acidic and confined imidodiphosphorimidate catalyst. Our approach provides tricyclic products in excellent stereoselectivity. We also report methods to convert the obtained products into useful intermediates and a computational study that aids in gaining deeper insight into the reaction mechanism and origin of stereoselectivity.
- Bistoni, Giovanni,Das, Sayantani,De, Chandra Kanta,Ghosh, Santanu,Leutzsch, Markus,List, Benjamin,Neese, Frank,Yepes, Diana
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supporting information
p. 12347 - 12351
(2020/03/23)
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- CeO2-Supported Pd(II)-on-Au Nanoparticle Catalyst for Aerobic Selective α,β-Desaturation of Carbonyl Compounds Applicable to Cyclohexanones
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Direct selective desaturation of carbonyl compounds to synthesize α,β-unsaturated carbonyl compounds represents an environmentally benign alternative to classical stepwise procedures. In this study, we designed an ideal CeO2-supported Pd(II)-on-Au nanoparticle catalyst (Pd/Au/CeO2) and successfully achieved heterogeneously catalyzed selective desaturation of cyclohexanones to cyclohexenones using O2 in air as the oxidant. Besides cyclohexenones, various bioactive enones can also be synthesized from the corresponding saturated ketones under open air conditions in the presence of Pd/Au/CeO2. Preliminary mechanistic studies revealed that α-C-H bond cleavage in the substrates is the turnover-limiting step of this desaturation reaction.
- Jin, Xiongjie,Mizuno, Noritaka,Takei, Daisuke,Yabe, Tomohiro,Yamaguchi, Kazuya,Yatabe, Takafumi
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p. 5057 - 5063
(2020/05/27)
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- Toward an Integrated Conversion of 5-Hydroxymethylfurfural and Ethylene for the Production of Renewable p-Xylene
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The use of biomass as a solution to satisfy the pressing needs for a fully sustainable biocommodity industry has been explored for a long time. However, limited success has been obtained. In this study, a highly effective two-stage procedure for the direct preparation of para-xylene (PX) from 5-hydroxymethylfurfural (HMF) and formic acid in one pot is described; these chemicals are two of the major bio-based feedstocks that offer the potential to address urgent needs for the green, sustainable production of drop-in chemical entities. The use of a robust, efficient heterogeneous catalyst, namely, bimetallic Pd-decorated Au clusters anchored on tetragonal-phase zirconia, is crucial to the success of this strategy. This multifunctional catalytic system can not only facilitate a low-energy-barrier H2-free pathway for the rapid, nearly exclusive formation of 2,5-dimethylfuran (DMF) from HMF but also enable the subsequent ultraselective production of PX by the dehydrative aromatization of the resultant DMF with ethylene. With increasing pressure around the world to move toward a bio-based economy, it is essential that industrially important commodity chemicals can be readily accessed from biomass resources. Para-xylene (PX) synthesis is one such target that is being actively pursued through the development of several biorefinery schemes based on integrated biomass processing. Significant progress has recently been achieved either in the selective synthesis of biorenewable PX from Diels-Alder-like coupling of ethylene with 2,5-dimethylfuran (DMF) or making DMF from 5-hydroxymethylfurfural (HMF) using hydrogen as the terminal reductant. However, a green and direct conversion of HMF, an essential feedstock source for future biorefinery schemes, into PX has yet to be developed. We have established an integrated process that directly converts HMF to PX in a highly compact and hydrogen-independent manner, thereby providing a new perspective on the potential of advanced biorefinery technologies. Cao and colleagues describe an alternative strategy for producing para-xylene through a more sustainable method than the current bio-based approaches. The strategy relies on an integrated conversion of 5-hydroxymethylfurfural with formic acid and ethylene, made possible by the use of a single multifunctional catalyst based on bimetallic Pd-decorated Au deposited on tetragonal-phase zirconia. The proposed process is particularly appealing because it is fully fossil independent, implying a viable and greener biorefinery scheme.
- Tao, Lei,Yan, Tian-Hao,Li, Wenqin,Zhao, Yi,Zhang, Qi,Liu, Yong-Mei,Wright, Mark M.,Li, Zhen-Hua,He, He-Yong,Cao, Yong
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supporting information
p. 2212 - 2227
(2018/10/02)
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- General, Simple, and Chemoselective Catalysts for the Isomerization of Allylic Alcohols: The Importance of the Halide Ligand
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Remarkably simple IrIIIcatalysts enable the isomerization of primary and sec-allylic alcohols under very mild reaction conditions. X-ray absorption spectroscopy (XAS) and mass spectrometry (MS) studies indicate that the catalysts, with the general formula [Cp*IrIII], require a halide ligand for catalytic activity, but no additives or additional ligands are needed.
- Erbing, Elis,Vázquez-Romero, Ana,Bermejo Gómez, Antonio,Platero-Prats, Ana E.,Carson, Fabian,Zou, Xiaodong,Tolstoy, P?ivi,Martín-Matute, Belén
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supporting information
p. 15659 - 15663
(2016/10/25)
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- Synthesis of α,β-unsaturated carbonyl compounds via a visible-light-promoted organocatalytic aerobic oxidation
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α,β-Unsaturated ketones and aldehydes have been synthesized from their corresponding silyl enol ethers in a straightforward protocol involving a visible-light promoted organocatalytic, aerobic oxidation reaction. A cheap organic dye was used catalytically in these reactions as the photosensitizer.
- Zhang, Junlin,Wang, Leming,Liu, Qi,Yang, Zhen,Huang, Yong
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supporting information
p. 11662 - 11664
(2013/12/04)
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- Acyloxybutadiene tricarbonyl iron complexes as enzyme-triggered CO-releasing molecules (ET-CORMs): A structure-activity relationship study
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A series of η4-acyloxycyclohexadiene-Fe(CO)3 complexes was prepared and fully characterized by spectroscopic methods including single crystal X-ray diffraction. For this purpose a new synthetic access to differently acylated 1,3- and 1,5-dienol-Fe(CO)3 complexes was developed. The enzymatically triggered CO release from these compounds was monitored (detection of CO through GC and/or by means of a myoglobin assay) and the anti-inflammatory effect of the compounds was assessed by a cellular assay based on the inhibition of NO-production by inducible NO synthase (iNOS). It was demonstrated that the properties (rate of esterase-triggered CO release, iNOS inhibition, cytotoxicity) of the complexes strongly depend on the substitution pattern of the π-ligand and the nature of the acyloxy substituent.
- Romanski, Steffen,Kraus, Birgit,Guttentag, Miguel,Schlundt, Waldemar,Rücker, Hannelore,Adler, Andreas,Neud?rfl, J?rg-Martin,Alberto, Roger,Amslinger, Sabine,Schmalz, Hans-Günther
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supporting information
p. 13862 - 13875
(2013/01/15)
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- Azepanone-based inhibitors of human cathepsin S: Optimization of selectivity via the P2 substituent
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A series of azepanone inhibitors of cathepsin S is described. Selectivity over both cathepsin K and cathepsin L was achieved by varying the P2 substituent. Ultimately, a balanced potency and selectivity profile was achieved in compound 39 possessing a 1-methylcyclohexyl alanine at P2 and nicotinamide as the P′ substituent. The cellular potency of selected analogs is also described.
- Kerns, Jeffrey K.,Nie, Hong,Bondinell, William,Widdowson, Katherine L.,Yamashita, Dennis S.,Rahman, Attiq,Podolin, Patricia L.,Carpenter, Donald C.,Jin, Qi,Riflade, Benoit,Dong, Xiaoyang,Nevins, Neysa,Keller, Paul M.,Mitchell, Laura,Tomaszek, Thaddeus
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scheme or table
p. 4409 - 4415
(2011/09/15)
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- Enzymatic resolution of racemic secondary cyclic allylic alcohols
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The resolutions of five racemic cyclic alcohols: 6,6-dimethylcyclohex-2-en-1-ol (±)-5, 4,4-dimethylcyclohex-2-en-1-ol (±)-7, 5,5-dimethylcyclohex-2-en-1-ol (±)-11 and isomeric trans-(±)-13 and cis-piperitols (±)-14 are presented. They were resolved by enzymatic esterification with vinyl esters or by enzymatic hydrolysis of their racemic esters in phosphate buffer. The following lipases were used as biocatalysts: Novozyme 435 (Candida antarctica), Amano PS (Burkholderia cepacia) and lipase from Candida cylindracea. All isomers of alcohols were obtained with at least 96% ee.
- Winska, Katarzyna,Grudniewska, Aleksandra,Chojnacka, Anna,Bialonska, Agata,Wawrzenczyk, Czeslaw
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experimental part
p. 670 - 678
(2010/08/07)
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- METHOD FOR PRODUCING CARBONYL COMPOUND AN PRO-OXIDANT USED FOR PRODUCTION OF CARBONYL COMPOUND
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The invention provides a process for the preparation of a carbonyl compound in high efficiency by oxidizing an alcohol. The process for the preparation of a carbonyl compound of the present invention includes a step of oxidizing an alcohol in the presence of a compound of the formula (I) or a derivative or a salt thereof, and an oxidant, wherein R1 and R2 independently represent hydrogen, a halogen, a nitro or acidic group, or an alkyl or alkoxy group, each of which optionally has a substituent, or R1 and R2 combine the two carbon atoms to which they are boned to form an aromatic ring.
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Page/Page column 15-16
(2009/08/16)
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- 2-iodoxybenzenesulfonic acid as an extremely active catalyst for the selective oxidation of alcohols to aldehydes, ketones, carboxylic acids, and enones with oxone
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Electron-donating group-substituted 2-iodoxybenzoic acids (IBXs) such as5-Me-IBX (1g), 5-MeO-IBX (1h), and 4,5-Me2-IBX were superior to IBX 1a as catalysts for the oxidation of alcohols with Oxone (a trad emark of DuPont) under nonaqueous conditions, although Oxone was almost insoluble in most organic solvents. The catalytic oxidation proceeded more rapidly and cleanly in nitromethane. Furthermore, 2-iodoxybenzenesulfonic acid (IBS, 6a) was much more active than modified IBXs. Thus, we established a highly efficient and selective method for the oxidation of primary and secondary alcohols to carbonyl compounds such as aldehydes, carboxylic acids, and ketones with Oxone in nonaqueous nitromethane, acetonitrile, or ethyl acetate in the presence of 0.05-5molpercentof 6a, which was generated in situ from 2-iodobenzenesulfonic acid (7a) or its sodium salt. Cycloalkanones could be further oxidized to α,β- cycloalkenones or lactones by controlling the amounts of Oxone under the same conditions as above. When Oxone was used under nonaqueous conditions, Oxone wastes could be removed by simple filtration. Based on theoretical calculations, we considered that the relatively ionic character of the intramolecular hypervalent iodine-OSO2 bond of IBS might lower the twisting barrier of the alkoxyperiodinane intermediate 16.
- Uyanik, Muhammet,Akakura, Matsujiro,Ishihara, Kazuaki
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supporting information; experimental part
p. 251 - 262
(2009/06/28)
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- Antipsychotic cyclic N-aralkylamines
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The invention relates to benzene derivatives, to pharmaceutical compositions containing them, to processes for preparing them, and to the method of use thereof in the treatment of psychotic disorders.
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- Asymmetric Baeyer - Villiger oxidations of 4-mono- and 4,4-disubstituted cyclohexanones by whole cells of engineered Escherichia coli
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Whole cells of an Escherichia coli strain that overexpresses Acinetobacter sp. NCIB 9871 cyclohexanone monooxygenase have been used for the Baeyer-Villiger oxidations of a variety of 4-mono- and 4,4-disubstituted cyclohexanones. In cases where comparisons were possible, this new biocatalytic reagent provided lactones with chemical yields and optical purities that were comparable to those obtained from the purified enzyme or a strain of bakers' yeast that expresses the same enzyme. The efficient production of cyclohexanone monooxygenase in the E. coli expression system (ca. 30% of total soluble protein) allowed these oxidations to reach completion in approximately half the time required for the engineered bakers' yeast strain. Surprisingly, 4,4-disubstituted cyclohexanones were also accepted by the enzyme, and the enantioselectivities of these oxidations could be rationalized by considering the conformational energies of bound substrates along with the enzyme's intrinsic enantioselectivity. The enzyme expressed in E. coli cells also oxidized several 4-substituted cyclohexanones bearing polar substituents, often with high enantioselectivities. In the case of 4-iodocyclohexanone, the lactone was obtained in > 98% ee and its absolute configuration was assigned by X-ray crystallography. The crystal belongs to the monoclinic P21 space group with a = 5.7400(10), b = 6.1650(10), c = 11.377(2) A, b = 99.98(2)°, and Z = 2. Taken together, these results demonstrate the utility of an engineered bacterial strain in delivering useful chiral building blocks in an experimentally simple manner.
- Mihovilovic,Chen,Wang,Kyte,Rochon,Kayser,Stewart
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p. 733 - 738
(2007/10/03)
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- Epoxidation of allylic alcohols in aqueous solutions of non surfactant amphiphilic sugars
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A variety of cyclic and acyclic allylic alcohols undergo efficient chemo-, regio- and/or stereoselective epoxidations in neutral aqueous solutions of amphiphilic carbohydrates (sucrose, L-arabinose, methyl or ethyl β-D-fructopyranoside) by using dilute hydrogen peroxide in the presence of molybdic or tungstic salts.
- Denis,Misbahi,Kerbal,Ferrieres,Plusquellec
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p. 2460 - 2461
(2007/10/03)
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- Process for the preparation of cyclic ketones
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The invention provides a process for the preparation of cyclic ketones of the general formula STR1 in which R represents an optionally substituted alkyl or cycloalkyl group and R 1 and R 2 independently represent an optionally substituted alkyl, cycloalkyl or aryl group, which comprises heating a compound of the general formula STR2 in which X represents a chlorine or bromine atom and R is as defined above, with a compound of the general formula STR3 in which R 1 and R 2 are as defined above, in the presence of an organic acid.Certain cyclic ketones of formula (I) are useful as intermediates in the preparation of certain fungicidally active cyclopentane derivatives.
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- AN EFFICIENT SYNTHESIS OF (+/-)-CUPARENE FROM 4,4-Dimethyl-2-CYCLOHEXEN-1-ONE
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An efficient synthesis of (+/-)-cuparene 1 from 4,4-dimethyl-2-cyclohexen-1-one 2 involves 1,4-addition by use of organozinc reagent, ozonolysis and Dieckmann condensation as the key steps.
- Shiao, Min-Jen,Liang, David,Ku, Chung-Shan,Yang, Chia-Hsi
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p. 1553 - 1564
(2007/10/02)
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- NOVEL TRANSFORMATIONS WITH BORONTRIFLUORIDE ETHERATE/IODIDE ION : FACILE CONVERSION OF 2-KETOOXIRANES AND 2-BROMO-2-ENONES TO THE α,β-UNSATURATED CARBONYL COMPOUNDS.
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Borontrifluoride etherate/iodide ion rapidly deoxygenates α-ketooxiranes, 3, to the corresponding α,β-unsaturated carbonyl compounds, 4, in near quantitative yields.In contrast, the reaction of 3 with borontrifluoride etherate/bromide ion, 2, yielded the corresponding 2-bromo-2-enone derivatives, 5, in excellent yields.The reagent 1, also dehalogenates a variety of 2-bromo-2-enones, 5, to the corresponding 2-en-1-one derivatives, 4, in high yields.
- Mandal, Arun K.,Mahajan, S. W.
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p. 2293 - 2300
(2007/10/02)
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- DIELS-ALDER REACTIONS OF 4,4-DIMETHYL-2-CYCLOHEXENONES. A DIRECT ROUTE TO THE 4,4-DIMETHYL-1-DECALONES
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Diels-Alder additions to enones 1 and 2, synthetic equivalents of the synthon 3, were studied using a variety of hydrocarbon dienes.The two enones have been shown to be effective and synthetically useful dienophiles.Spectroscopic (especially 1H and 13C magnetic resonance) and chemical techniques were used to define unambiguously the full structures of the adducts.The structures of the various reaction products were used to draw qualitative conclusions about the nature of the transition states involved and the various electronic and steric effects that play a role in the mechanistic course of the Diels-Alder reaction.
- Liu, Hsing-Jang,Browne, Eric N. C.
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p. 1262 - 1278
(2007/10/02)
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- 1,5-DICARBONYL COMPOUNDS A GENERAL PREPARATION METHOD
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In this report, a general method for the preparation of 1,5-dicarbonyl compounds and six membered ring annelation is described.This method involves the reaction of hemiacetal vinylogs 1 with enol ethers 2 or 3 in the presence of a Lewis acid.This reaction was successfully applied to the enol ethers of α and α,α'-hindered ketones such as 2,2,6-trimethyl cyclohexanone. α-Cyperone and 6-epi-α-cyperone were obtained using this process.
- Duhamel, P.,Hennequin, L.,Poirier, J. M.,Tavel, G.,Vottero, C.
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p. 4777 - 4786
(2007/10/02)
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- Cyanothiolacetate as a masked β-hydroxypropionitrile carbanion in Michael reactions
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A facile method for the introduction of a highly functionalized isopropyl unit, in the form of β-hydroxyproprionitrile or acrylonitrile, to the β carbon of an α,β-unsaturated ketone has been developed using S-tert-butyl cyanothiolacetate as a β-hydroxyproprionitrile equivalent in Michael reactions.
- Liu, Hsing-Jang,Wynn, Hla
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p. 649 - 657
(2007/10/02)
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- Selective Monohydrogenation of Cross Conjugated Cyclohexadienones with Iron Carbonyls and Water
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The cross conjugated cyclohexadienone systems 1, 4a, b and 8 are under mild conditions selectively monohydrogenated with Fe2(CO)9 and water, trapped as iron tricarbonyl dienol complexes 11, 5a, b and 9 and therefore protected against further hydrogenation. - Based on deuterium labelling experiments the mechanism and stereochemistry of this hydrogenation is interpreted via various metal hydrides.A skeletal rearrangement of santonin (1) with Fe2(CO)9 described earlier by other authors does not occur according to these investigations.
- Eilbracht, Peter,Jelitte, Ruediger
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p. 243 - 253
(2007/10/02)
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- Origins of Regio- and Stereoselectivity in Additions of Phenylselenenyl Chloride to Allylic Alcohols and the Applicability of These Additions to a Simple 1,3-Enone Transposition Sequence
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The regio- and stereoselectivity of phenylselenenyl chloride additions to allylic alcohols and their derivatives have been systematically studied.On the basis of the results, a mechanism involving two basic premises is proposed.These are as follows: (a) allylic oxygen's direct selenonium ion formation to the syn face of the double bond; (b) axial attack of the chloride ion is kinetically favored over equatorial attack.A series of rules which are useful for predicting the regio- and stereoselectivity of phenylselenenyl chloride additions to allylic systems are discussed.In addition, these reactions can be used as the key step in a general 1,3-enone transposition sequence.Several examples of this transposition sequence are illustrated.
- Liotta, Dennis,Zima, George,Saindane, Manohar
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p. 1258 - 1267
(2007/10/02)
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- Metal-Catalyzed Organic Photoreactions. One-Step Synthesis of Chlorinated Ketones from Olefins by Photooxidation in the Presence of Iron(III) Chloride
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Under photooxidation in pyridine in the presence of FeCl3, mono- and disubstituted olefins gave α-chloro ketones, while tri- and tetrasubstituted olefins gave dichloro ketones with a C-C bond cleavage.The reaction was interpreted in terms of an electron-transfer mechanism occurring within the coordination sphere of the iron ion
- Kohda, Akira,Ueda, Keiko,,Sato, Tadashi
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p. 509 - 515
(2007/10/02)
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- Anti-androgen compounds
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Compounds of the formula STR1 in which each R is hydrogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, hydroxy, cyano, or halo, and both R groups are identical and are symmetrically located; R 1 is C 1 -C 3 alkyl and R 2 is methyl, or R 1 and R 2 taken together are (CH 2 -- n in which n is an integer from 4 to 6; and (1) X c and X d are hydrogen, and the combination of X a and Y a and of X b and Y b each represents a double bond, subject to the limitation that, when R 1 is C 1 -C 3 alkyl and is other than methyl, X c, X d, and R 1 are all in an α-configuration; or (2) X a, X b, X c, X d, Y a, and Y b are hydrogen, subject to the limitation that both X c and X d are in an α-configuration, both X a and X b are in an α-configuration or in a β-configuration, and, R 1, when it is C 1 -C 3 alkyl, is in an α-configuration, are useful in inhibiting the action of androgens or are intermediates to such anti-androgen compounds.
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