- Rhodium complexes catalyze oxidative coupling between salicylaldehyde and phenylacetylene via C-H bond activation
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A coupling reaction between salicylaldehyde and phenylacetylene was catalyzed by well-defined rhodium complexes, Rh(cod)(l-amino acid) (cod is 1,5-cyclooctadiene; l-amino acid is l-proline, l-phenylalanine and l-valine), to give a flavonoid in 40-88% yield, providing a method for flavonoid synthesis. The coupling reactions catalyzed by Rh(cod)(l-amino acid)s gave higher yields than those by [Rh(cod)Cl]2 without l-amino acid ligands. The reaction mechanism may be that l-amino acid ligands of the rhodium complexes can provide an empty track for phenylacetylene to form a ring structure that fractures to produce the aim flavonoid and RhIX species. Then, the active RhIX specie is oxidized to regenerate RhIIIX3 by Cu(OAC)2.
- Jia, Hongge,Tang, Yanan,Shi, Yongqiang,Ma, Liqun,He, Zijian,Lai, Weiwei,Yang, Yi,Wang, Yazhen,Zang, Yu,Xu, Shuangping
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Read Online
- Stille coupling for the synthesis of isoflavones by a reusable palladium catalyst in water
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Isoflavones were synthesized from the reaction of 3-bromochromone derivatives and aryltributylstannanes via Stille coupling catalyzed by a water-soluble and reusable PdCl2(NH3)2/2,2′-cationic bipyridyl system in aqueous solution. For prototype 3-bromochromone, the coupling reaction was performed at 80°C for 24 hr with 2.5 mol% catalyst in water in the presence of tetrabutylammonium fluoride. After the reaction, the aqueous solution could be reused for several runs, indicating that its activity was only slightly decreased. For substituted 3-bromochromones, the addition of NaHCO3 and a higher reaction temperature (120°C) were required to gain satisfactory outcomes. In addition, naturally occurring products, such as daidzein, could be obtained by this protocol via a one-pot reaction.
- Chang, Ya-Ting,Liu, Ling-Jun,Peng, Wen-Sheng,Lin, Lin-Ting,Chan, Yi-Tsu,Tsai, Fu-Yu
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p. 469 - 475
(2021/02/03)
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- Identification of ortho catechol-containing isoflavone as a privileged scaffold that directly prevents the aggregation of both amyloid β plaques and tau-mediated neurofibrillary tangles and its in vivo evaluation
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In this study, polyhydroxyisoflavones that directly prevent the aggregation of both amyloid β (Aβ) and tau were expediently synthesized via divergent Pd(0)-catalyzed Suzuki-Miyaura coupling and then biologically evaluated. By preliminary structure–activity relationship studies using thioflavin T (ThT) assays, an ortho-catechol containing isoflavone scaffold was proven to be crucial for preventing both Aβ aggregation and tau-mediated neurofibrillary tangle formation. Additional TEM experiment confirmed that ortho-catechol containing isoflavone 4d significantly prevented the aggregation of both Aβ and tau. To investigate the mode of action (MOA) of 4d, which possesses an ortho-catechol moiety, 1H-15N HSQC NMR analysis was thoroughly performed and the result indicated that 4d could directly inhibit both the formation of Aβ42 fibrils and the formation of tau-derived neurofibrils, probably through the catechol-mediated nucleation of tau. Finally, 4d was demonstrated to alleviate cognitive impairment and pathologies related to Alzheimer's disease in a 5XFAD transgenic mouse model.
- Do, Ji Min,Gee, Min Sung,Inn, Kyung-Soo,Kim, Jong-Ho,Kim, Nam Kwon,Kim, Nam-Jung,Lee, Hyun Woo,Lee, Jong Kil,Seo, Min-Duk,Seong, Ji Hye,Son, Seung Hwan,Yoo, Hyung-Seok,Yoo, Ji-Na
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- The oxidative coupling between benzaldehyde derivatives and phenylacetylene catalyzed by rhodium complexes via C-H bond activation
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This paper reports the use of rhodium (Rh) catalysts for the oxidative coupling reaction between phenylacetylene and benzaldehyde derivatives via C-H bond activation. These reactions were catalyzed by Rh(l-amino acid)(cod) (the l-amino acid is l-phenylala
- Jia, Hongge,Ma, Liqun,Shi, Yongqiang,Song, Heming,Tang, Yanan,Wang, Qingji,Wang, Yazhen,Xu, Shuangping,Yang, Guoxing,Zang, Yu,Zhao, Xinyi
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- Ionic liquids and ohmic heating in combination for Pd-catalyzed cross-coupling reactions: Sustainable synthesis of flavonoids
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In order to meet the increasing demand for environmentally benign chemical processes, we developed a Suzuki-Miyaura reaction protocol based on the combination of ohmic heating (?H) and supported ionic liquid phase catalysis (SILPC) in aqueous media. This methodology was applied to the synthesis of a series of flavonoid derivatives, including isoflavones, styrylisoflavones, and diarylalkenylisoflavones.
- Silva, Artur M. S.,Silva, Vera L. M.,Soengas, Raquel G.
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- Decarboxylative Suzuki-Miyaura coupling of (hetero)aromatic carboxylic acids using iodine as the terminal oxidant
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A novel methodology for the decarboxylative Suzuki-Miyaura-type coupling has been established. This process uses iodine or a bromine source as both the decarboxylation mediator and the terminal oxidant, thus avoiding the need for stoichiometric amounts of transition metal salts previously required. Our new protocol allows for the construction of valuable biaryl architectures through the coupling of (hetero)aromatic carboxylic acids with arylboronic acids. The scope of this decarboxylative Suzuki reaction has been greatly diversified, allowing for previously inaccessible non-ortho-substituted aromatic acids to undergo this transformation. The procedure also benefits from low catalyst loadings and the absence of stoichiometric transition metal additives.
- Quibell, Jacob M.,Duan, Guojian,Perry, Gregory J.P.,Larrosa, Igor
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p. 6445 - 6448
(2019/06/07)
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- Transient and Recyclable Halogenation Coupling (TRHC) for Isoflavonoid Synthesis with Site-Selective Arylation
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A transient and recyclable C?H iodination has been designed for the synthesis of isoflavonoids through the domino reactions of o-hydroxyphenyl enaminones and aryl boronic acids in the presence of catalytic KI and Pd catalyst. Instead of the conventional cross-coupling strategy employing pre-halogenated substrates, this method transforms raw C?H bond by means of a transient C?H halogenation to smoothly relay the subsequent C-arylation. Consequently, such a method avoids the pre-functionalization for C?halogen bond installation as well as the generation of stoichiometric halogen-containing waste following the cross-coupled product, disclosing an intriguing new coupling protocol to forge the C?C bond in the virgin area between classical C?X (X=halogen) bond cross coupling and the C?H activation.
- Wan, Jie-Ping,Tu, Zhi,Wang, Yuyun
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supporting information
p. 6907 - 6910
(2019/05/10)
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- Unexpected detection of 3-aroylbenzofuran side products in the preparation of 2-arylbenzofurans: Identification, characterization, and comparison with chalcone's fragmentation patterns using EI/MSn
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A gas chromatography-mass spectrometry study of the intramolecular Wittig reaction revealed, together with the expected 2-phenylbenzofuran, the formation of an unexpected side product that has not been reported until now. This study reports the identification of the by-product, ie, the 3-benzoyl-2-phenylbenzofuran, on the base of its mass spectrometric behaviour using a combination of electron ionization, exact mass measurement, multiple stage mass spectrometry, and labelled compounds. This study reports the common fragmentation pathways and discusses possible fragment structures of characteristic ions from a series of 3-aroyl-2-arylbenzofuran derivatives obtained as by-product under Wittig conditions. Emphasis is laid on the formation and structure investigation of the [M-H]+ and [M-OH]+ ions. Our results showed interesting analogies with the mass spectrometric behaviour of chalcones.
- Begala, Michela,Delogu, Giovanna Lucia
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p. 750 - 760
(2019/09/03)
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- Pot-economic synthesis of diarylpyrazoles and pyrimidines involving Pd-catalyzed cross-coupling of 3-trifloxychromone and triarylbismuth
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Abstract: The present study reveals the formation of 3,4-diarylpyrazole and 4,5-diarylpyrimidine in one-pot operation starting from 3-trifloxychromone and triarylbismuth. The complete process encompasses two steps in the one-pot operation. The first step leads to the formation of isoflavone via cross-coupling reaction of 3-trifloxychromone and triarylbismuth as a threefold arylating reagent. These isoflavones were further converted into 3,4-diarylpyrazole and 4,5-diarylpyrimidine using hydrazine hydrate and guanidinium chloride in the successive step in the same pot. Interestingly the formation of 3,4-diarylpyrazole was achieved in the shortest reaction time i.e., 30 min that too at room temperature. Overall the developed methodology provides easy access to the medicinally important diarylpyrazole and pyrimidine moiety in one-pot operation and in short reaction time. Graphical Abstract: Synopsis The work presented here describes the novel methodology for the formation of medicinally important heterocycles 3,4-diarylpyrazole and 4,5-diarylpyrimidine in one-pot operation starting from 3-trifloxychromone and triarylbismuth.
- Kumar, Abhijeet,Rao, Maddali L N
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- Synthesis, crystal structure, characterization and antifungal activity of 3,4-diaryl-1H-Pyrazoles derivatives
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A series of 3,4-diaryl-1H-pyrazoles derivatives were designed and synthesized by the reaction of 3-heteroarylchromones and 3-phenylchromones with hydrazine hydrate in good yields. All of those compounds were characterized by 1H NMR, 13C NMR, IR, and HRMS. Moreover, 3-(2,4-dihydroxyphenyl)-4-(4-hydroxyphenyl)-1H-pyrazole and 3-(2,4-dihydroxy phenyl)-4-(4-methoxyphenyl)-1H-pyrazole were further conformed by the single crystal X-ray diffraction. In addition, the antifungal activity against five phytopathogenic fungi (Cytospora sp., Colletotrichum gloeosporioides, Botrytis cinerea, Alternaria solani and Fusarium solani) of 3,4-diaryl-1H-pyrazoles were evaluated. 3-(2-Hydroxy-4-isopropoxyphenyl)-4-phenyl-1H-pyrazole was more better and broader inhibitory effect on Cytospora sp., C. gloeosporioides, A. solani and Fusarium solani with IC50 values of 26.96, 28.84, 16.77 and 22.10 μg/mL, respectively. 4-(4-Fluorophenyl)-3-(2-hydroxy-4-methoxyphenyl)-1H-pyrazole exhibited fairly effective antifungal activity against Cytospora sp., C. gloeosporioides and A. solani with IC50 values of 11.91, 14.92 and 16.98 μg/mL, respectively.
- Zhang, Jin,Tan, Da-Jin,Wang, Tao,Jing, Si-Si,Kang, Yang,Zhang, Zun-Ting
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p. 235 - 242
(2017/08/09)
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- ANTI-VIRAL COMPOUNDS, PHARMACEUTICAL COMPOSITIONS, AND METHODS OF USE THEREOF
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Disclosed herein are compounds and pharmaceutical compositions, and uses thereof for the treatment of viral infections, including RNA viral infections. The compounds, pharmaceutical compositions, and methods disclosed herein can relate to chromenone drug candidate compounds that modulate innate immunity along the RLR-IRF3 axis. These compounds activate innate immune signaling downstream of numerous viral countermeasures and are a unique addition to conventional antiviral compounds in development or on the market. These compounds possess broad spectrum in vitro activity against diverse RNA viruses including the respiratory pathogens influenza, RSV, and hCoV, with EC50 values in the low nanomolar range. Potent in vitro activity is also demonstrated against systemic and emerging viruses including Dengue and Ebola.
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Paragraph 0165
(2016/06/01)
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- Synthesis, antimycobacterial evaluation and pharmacophore modeling of analogues of the natural product formononetin
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Abstract The synthesis and antimycobacterial activity of formononetin analogues is hereby reported. Formononetin and its analogue 11E showed 88% and 95% growth inhibition, respectively, against the H37Rv strain of Mycobacterium tuberculosis. Pharmacophore modeling studies indicated that the presence of a hydroxyl group in formononetin and its analogues, is crucial for maintaining activity.
- Mutai, Peggoty,Pavadai, Elumalai,Wiid, Ian,Ngwane, Andile,Baker, Bienyameen,Chibale, Kelly
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p. 2510 - 2513
(2015/06/02)
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- Oxidative regioselective amination of chromones exposes potent inhibitors of the hedgehog signaling pathway
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A transition metal-free, oxidative, regioselective cross-coupling between non-functionalized azoles and chromones at C2-position was developed. A broad reaction scope and further transformation of products were demonstrated. The biological evaluation of products revealed a novel class of hedgehog signaling pathway inhibitors. This journal is
- Samanta, Rajarshi,Narayan, Rishikesh,Bauer, Jonathan O.,Strohmann, Carsten,Sievers, Sonja,Antonchick, Andrey P.
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supporting information
p. 925 - 928
(2015/01/09)
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- Development of a general approach to the synthesis of a library of isoflavonoid derivatives
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Isoflavonoids are a class of organic compounds that act primarily as antioxidants. They are produced almost exclusively by various members of the bean family including soybeans, tofu, peanuts, chick peas, and alfalfa. The antioxidant characteristics that isoflavonoids exhibit help hinder the progression of certain cancers, primarily breast, prostate, and colon cancer. We have developed a three-five step synthesis for obtaining a suite of isoflavonoid derivatives. The synthesis involves an enamine formation, a ring closure and halogenation, a Suzuki coupling, and finally a global deprotection to obtain the respective isoflavonoid derivatives.
- Biegasiewicz, Kyle F.,Gordon, James S.,Rodriguez, Deana A.,Priefer, Ronny
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p. 5210 - 5212
(2014/12/11)
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- Oxidation of enol acetate of flavanone with thallium(III) nitrate or phenyliodonium diacetate: A convenient new route to isoflavone and flavone
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A new high-yield method has been described for the preparation of isoflavone by oxidation of enol acetate of flavanone with thallium(III) nitrate or phenyliodonium diacetate in trimethyl orthoformate in the presence of 70 % perchloric acid at room temperature. Flavone could also be prepared in high yield from the enol acetate by oxidation with the same reagents in glacial acetic acid at room temperature. Some key intermediates of these oxidations were investigated with quantum chemical (HF and DFT) methods. Graphical Abstract: [Figure not available: see fulltext.].
- Nemeth, Istvan,Kiss-Szikszai, Attila,Gulacsi, Katalin,Mandi, Attila,Komaromi, Istvan,Kurtan, Tibor,Antus, Sandor
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p. 849 - 855
(2014/05/20)
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- Novel synthesis of 3-phenyl-chromen-4-ones using n-heterocyclic carbene as organocatalyst: An efficient domino catalysis type approach
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Herein is reported a simple and efficient synthesis of isoflavones starting from various substituted phenacyl bromides and salicylaldehydes in presence of NHC. The mechanism involved domino catalysis type approach with consumption and regeneration of catalyst in two catalytic cycles. This method proved to be very lucrative and gives very good yield. The method described here represents an environmentally benign alternative to classical approach.
- Mishra, Priya,Singh, Sarita,Ankit, Preyas,Fatma, Shahin,Singh, Divya,Singh, Jagdamba
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p. 1070 - 1076
(2013/07/28)
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- Oxidative rearrangement of flavanones with thallium(III) nitrate, lead tetraacetate and hypervalent iodines in trimethyl orthoformate and perchloric or sulfuric acid
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An HPLC monitoring protocol has been developed to follow the reaction of flavanone [(±)-1] with thallium(III) nitrate, lead tetracetate, phenyliodonium diacetate (PIDA) or [hydroxyl(tosyloxy)iodo]benzene in trimethyl orthoformate. Besides the major ring-c
- Nemeth, Istvan,Kiss-Szikszai, Attila,Zita Illyes, Tuende,Mandi, Attila,Komaromi, Istvan,Kurtan, Tibor,Antus, Sandor
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p. 1289 - 1296
(2013/02/23)
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- Palladium-catalyzed oxidative arylation of chromones via a double C-H activation: An expedient approach to flavones
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A palladium-catalyzed oxidative arylation of chromones was examined. A regioselective 2-arylation of chromone was carried out via a double C-H activation process. The procedure provided an expedient approach for the preparation of flavone derivatives.
- Kim, Ko Hoon,Lee, Hyun Seung,Kim, Se Hee,Kim, Jae Nyoung
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scheme or table
p. 2761 - 2764
(2012/07/14)
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- A novel synthesis of isoflavones via copper(I)-catalyzed intramolecular cyclization reaction
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Isoflavone derivatives were synthesized via intramolecular cyclization of 3-(2-bromophenyl)-3-oxopropanal derivatives, using CuI as the catalyst, 2-picolinic acid (=pyridine-2-carboxylic acid) as the ligand, K 2CO3 as the base, and DMF as the solvent, in up to 96% yield. The synthesis is functional group-tolerant. Copyright
- Li, Qiu-Lian,Liu, Qi-Lun,Ge, Zhi-Yuan,Zhu, Yong-Ming
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p. 1304 - 1309
(2011/09/15)
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- Palladium-catalyzed oxidative cross-coupling reaction of arylboronic acids with diazoesters for stereoselective synthesis of (E)-α,β- diarylacrylates
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A Pd-catalyzed oxidative cross-coupling reaction of arylboronic acids with α-diazoesters was achieved using molecular oxygen as the sole reoxidant, and E-α,β-diarylacrylates were obtained in good yields and >20:1 E-to-Z selectivity.
- Tsoi, Yuk-Tai,Zhou, Zhongyuan,Chan, Albert S. C.,Yu, Wing-Yiu
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supporting information; experimental part
p. 4506 - 4509
(2010/12/25)
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- Oxidative rearrangements of 2'-hydroxychalcones with lh-l-hydroxy-5-methyl- l,2,3-benziodoxathiole 3,3-dioxide
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1H-l-hydroxy-5-methyl-l,2,3-benziodoxathiole 3,3-dioxide (HMBI) has been found to effect the direct conversion of 2'-hydroxychalcones with various B-ring substituents to isoflavones in moderate to good yield (34-83%) in methanol under reflux. The reduced byproduct of HMBI is easily recovered by aqueous extraction and can be recycled and reused with high efficiency. Previous reports of conversions of this type required the use of toxic thallium(III) salts or initial protection of the 2'-hydroxyl group.
- Justik, Michael W.,Zimmerman, Alyssa K.
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scheme or table
p. 67 - 71
(2010/03/03)
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- Pd-Catalyzed efficient cross-couplings of 3-iodochromones with triarylbismuths as substoichiometric multicoupling organometallic nucleophiles
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An efficient cross-coupling of 3-iodochromones with triarylbismuths under catalytic palladium conditions is reported. Triarylbismuths were employed as substoichiometric multicoupling nucleophiles for the synthesis of a variety of substituted isoflavones.
- Rao, Maddali L. N.,Venkatesh, Varadhachari,Jadhav, Deepak N.
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experimental part
p. 2597 - 2600
(2010/01/16)
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- Catalytic asymmetric alkylation of substituted isoflavanones
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The asymmetric alkylation of isoflavanones (3-aryl-chroman-4-ones) and protected 3-phenyl-2,3-dihydroquinolin-4(1H)-ones catalyzed by a novel cinchonidine-derived phase transfer catalyst E is reported. This functionalization occurs at the unactivated C3 methine to afford novel products that can easily be functionalized to generate more complex fused ring systems. The process accommodates a variety of isoflavanones and activated electrophiles and installs a stereogenic quaternary center in high yield and with good-to-excellent selectivity. Isoflavanones are a privileged class of natural products with a broad spectrum of biological activities including insecticidal, antimicrobial, antibacterial, estrogenic, antitumor, and anti-HIV activity. 1 Isoflavanones are also precursors for more complex natural products such as pterocarpans and rotenones.1 Given their therapeutic promise, selective strategies to access new classes of isoflavanones and related structures has high value.2 The functionalization of the C3 position could promote beneficial interactions with biological targets of interest. Specifically, an alkylation at C3 can rapidly access new members of the general class of biologically active homoisoflavanones.3
- Nibbs, Antoinette E.,Baize, Amanda-Lauren,Herter, Rachel M.,Scheidt, Karl A.
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supporting information; experimental part
p. 4010 - 4013
(2009/12/05)
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- Synthesis of isoflavones via base catalysed condensation reaction of deoxybenzoin
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Base catalysed condensation reaction of o-hydroxyl-α- phenylacetophenones with formyl reagents affords various substituted isoflavones. Many bases were tested in the condensation reaction and DMAP was found to be the most effective catalysis.
- Li, Wanmei,Liu, Fangming,Zhang, Pengfei
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scheme or table
p. 683 - 685
(2009/09/25)
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- Practical synthesis of lespedezol A1
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A practical formal synthesis of lespedezol A1 (1) was accomplished in 33% yield for four steps starting from formation of the substituted chalcone. Of particular note is a useful protocol for reduction of the 2-ene bond in the isoflavone intermediate. A significant improvement in the final ring closure when water was scavenged from the reaction is also noteworthy. The ready availability of lespedezol A1 will provide material for further pharmacological evaluation and for exploration of the pterocarpene nucleus as a potential entry into various 6a-hydroxypterocarpans.
- Khupse, Rahul S.,Erhardt, Paul W.
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p. 275 - 277
(2008/12/23)
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- Direct syntheses of benzofuran-2(3H)-ones and benzofuran-3(2H)-ones from 1-(2-hydroxyphenyl)alkan-1-ones by CuBr2 or CuCl2
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New syntheses of benzofuran-2(3H)-ones and benzofuran-3(2H)-ones from 1-(2-hydroxyphenyl)alkan-1-ones via oxidative cyclization by CuBr2 or CuCl2 are described. A new synthesis of 1H-isochromene-1,4(3H)- diones via similar procedures is also described. Copyright
- Miyake, Hideyoshi,Nishimura, Akinori,Yago, Misato,Sasaki, Mitsuru
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p. 332 - 333
(2008/02/04)
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- Rapid syntheses of (±)-pterocarpans and isoflavones via the gold-catalyzed annulation of aldehydes and alkynes
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(±)-Pterocarpan and analogues (4a-c) have been synthesized efficiently via the annulation of salicylaldehydes (1a, 1b and 1c) and o-methoxymethoxylphenylacetylene (2a), followed by a one-pot reduction and acidic cyclization of the ketones (3a-c). In addition, isoflavone derivatives (5a-c) have been synthesized rapidly, in two steps, via the annulation of salicylaldehyde (1a) and arylacetylenes (2b, 2c and 2d), followed by IBX/DMSO oxidation of the isoflavanones (3d, 3e and 3f).
- Skouta, Rachid,Li, Chao-Jun
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p. 8343 - 8346
(2008/03/14)
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- Microwave-assisted Suzuki-Miyaura and Heck-Mizoroki cross-coupling reactions of aryl chlorides and bromides in water using stable benzothiazole-based palladium(II) precatalysts
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The catalytic activity of benzothiazole-based Pd(II)-complexes was evaluated in Suzuki-Miyaura and Heck-Mizoroki C-C cross-coupling reactions of aryl chlorides and bromides with olefins and arylboronic acids both under thermal as well as microwave irradiation conditions in water. The factors affecting the optimization of such reactions as well as the reusability of the Pd-precatalysts are studied.
- Dawood, Kamal M.
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p. 9642 - 9651
(2008/02/12)
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- Oxazoline Chemistry. Part 11: Syntheses of natural and synthetic isoflavones, stilbenes and related species via C-C bond formation promoted by a Pd-oxazoline complex
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The complex trans-[PdCl2(2-ethyl-2-oxazoline- κ1N)2] (1) is shown to be an active and oxidatively robust catalyst for C-C bond forming reactions (Heck, Sonogashira, Ullmann, Miyaura-Suzuki, etc.). These reactions can be carried out in air without rigorous solvent/substrate purification and in the absence of additional free ligand. The general methodology described above has been applied to the high yield and regio-selective formation, via Miyaura-Suzuki coupling, of natural and synthetic isoflavones (i.e., isoflavone, 2′-methylisoflavone [7b], 3′-methylisoflavone [7c] and 3′,4′-benzoisoflavone: [7d]). Compounds 7c and 7d are previously unknown. In addition, the synthesis of (E)-tris-O-methylresveratrol and (E)-3,5-dimethoxystilbene is also described; the former is a recognized anti-cancer agent while the latter is a biologically active extract from the bark of the conifer species Pinus armandii. Both of these latter products are produced as a result of a Heck coupling reaction promoted by 1.
- Eisnor, Charles R.,Gossage, Robert A.,Yadav, Paras N.
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p. 3395 - 3401
(2007/10/03)
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- Facile deoxygenation of hydroxylated flavonoids by palladium-catalysed reduction of its triflate derivatives
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An efficient procedure to deoxygenate hydroxy substituted flavonoids, isoflavonoids and related compounds via their trifluoromethanesulfonates is presented. Their reduction with formic acid in the presence of a catalytic amount of palladium acetate, triethylamine and 1,3-bis(diphenyl-phosphanyl) propane (dppp) in DMF results in their des-hyaroxy derivatives without affecting other functional groups.
- K?vér, József,Antus, Sándor
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p. 792 - 796
(2007/10/03)
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- COMPOSITION CONTAINING ISOFLAVONE OF HIGH PURITY AT HIGH CONCENTRATION AND PROCESS FOR PRODUCING THE SAME
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It is intended to provide a composition containing isoflavones which has a high purity and yet is highly soluble in water in a natural state without adding any solubilizers or subjecting to chemically modification. It is found out that a composition containing isoflavones with a high purity and a high solubility in water can be obtained by extracting soybean hypocotyls with a water-containing alcohol within a specific temperature range, then allowing a synthetic adsorbent resin to adsorb the obtained extract and eluting with a water-containing alcohol at a specific concentration.
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- Practical and efficient Suzuki-Miyaura cross-coupling of 2-iodocycloenones with arylboronic acids catalyzed by recyclable Pd(0)/C
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The first Suzuki-Miyaura cross-coupling of 2-iodocycloenones with arylboronic acids catalyzed by 10% Pd(0)/C is described as an interesting alternative to classical homogeneous conditions. Most of the substrate reacted under mild condition at 25 °C under air in aqueous DME. The conditions described tolerate a wide range of iodoenones and boronic acids. Notably, the procedure features inexpensive reagents and solvents with low toxicity rendering the method environmentally benign. Additionally 10% Pd(0)/C could be recovered and efficiently reused at least five times without significant alteration of the yields of the cross-coupled product.
- Felpin, Francois-Xavier
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p. 8575 - 8578
(2007/10/03)
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- Process for isolating phenolic compounds
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The invention provides compositions and methods for isolating phenolic compounds, particularly isoflavones, from aqueous extracts of plant materials that contain such compounds. The process comprising: (a) providing an aqueous plant extract at a first pH less than 10, the aqueous plant extract comprising a plurality of phenolic compounds; (b) extracting the aqueous plant extract with a first organic solvent to yield a first organic extract; (c) extracting the first organic extract with an aqueous phase of pH greater than 10 to yield a phenol rich aqueous phase; (d) adjusting the pH of the phenol rich aqueous phase to a pH of less than 9; and (e) isolating the phenolic compounds from the phenol rich aqueous phase.
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- A novel synthesis of 2,3-disubstituted benzopyran-4-ones and application to the solid phase
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The development of a novel synthesis of 2,3-disubstituted benzopyran-4- ones and application to the solid phase are reported. Following model studies using benzyl alcohol as a surrogate for polystyrene hydroxymethyl resin, we utilized our previously established traceless diisopropylsilyloxy tinker methodology to synthesize a small library of target benzopyranones in generally high yield and purity. (C) 2000 Elsevier Science Ltd.
- Harikrishnan, Lalgudi S.,Showalter, H.D.Hollis
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p. 515 - 519
(2007/10/03)
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- Palladium-Catalyzed Carbonylative Cross-Coupling Reaction of Arylboronic Acids with Aryl Electrophiles: Synthesis of Biaryl Ketones
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The carbonylative cross-coupling reaction of arylboronic acids with aryl electrophiles (ArI, ArBr, and ArOTf) to yield unsymmetrical biaryl ketones was carried out in anisole at 80°C in the presence of a palladium catalyst and a base. The reaction selectively proceeded under an atmospheric pressure of carbon monoxide when PdCl2(PPh3)2 (3 mol %)/K2CO3 (3 equiv) were used for aryl iodides and PdCl2(dppf) (3 mol %)/K2CO3 (3 equiv)/KI (3 equiv) for the bromides or the triflates. The carbonylation of arylboronic acids with benzyl halides gave aryl benzyl ketones.
- Ishiyama, Tatsuo,Kizaki, Hiroe,Hayashi, Takahiro,Suzuki, Akira,Miyaura, Norio
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p. 4726 - 4731
(2007/10/03)
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- Sialic acid/fucose based medicaments
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Compounds that exhibit selectin binding activity are described and have the following structural formula: STR1 where W is selected from a group including structures a-d below STR2 wherein p is an integer of from 0-2, q is an integer of from 0-3, and r is an integer of from 0-5; A is selected from the group consisting of α and β forms of sialic acid, Kemp's acid, quinic acid, R and S forms of mandelic acid, R and S forms of glyceric acid, R and S forms of lactic acid, propionic and acetic acid, and esters and amides thereof, --SO3, sulfonate, --PO3, phosphonate, trifluoromethyl, diazine and triazine; B is selected from a group consisting of α and β forms of fucose, arabinose and esters and substituted forms thereof wherein one or more of the OH groups is independently substituted with F, N3, NHAc, NHCOCF3. The remaining variable are described in the specification.
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- Hypervalent Iodine Oxidation of Flawanones: Convenient and Useful Syntheses of Flavones and IsoFlavones
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Hypervalent iodine oxidation of flavanones (1a-g) under a variety of conditions, offering convenient and valuable routes to the syntheses of flavones (2a-g) and isoflavones (3a-g), is described.The course of these oxidation reactions is greatly influenced by the reaction conditions and it is possible to select appropriate conditions for following a desired route (2/3).The mechanistic rationale for these transformations is also discussed.
- Prakash, Om,Tanwar, Madan P.
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p. 1429 - 1447
(2007/10/02)
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- Organolead-mediated Arylation of Allyl β-Ketoesters: A Selective Synthesis of Isoflavanones and Isoflavones
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Arylation of A-ring substituted and unsabstituted 3-allyloxycarbonylchroman-4-ones with aryllead(IV) triacetates followed by selective catalytic deallyloxycarbonylation affords isoflavanones or isoflavones in high overall yields.The highest yield in the arylation step was observed in the reaction of 5,7-dimethoxychroman-4-one with the more hindered 2,4,6-trimethoxyphenyllead triacetate.
- Donnelly, Dervilla M.,Finet, Jean-Pierre,Rattigan, Bernard A.
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p. 1729 - 1736
(2007/10/02)
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- Aryllead mediated synthesis of isoflavanone and isoflavone derivatives
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The reaction of aryllead (IV) triacetates with 3-(phenylthio)-chroman-4-one and 2-p-methoxyphenyl-3-(phenylthio)-chroman-4-one derivatives was carried out in chloroform in presence of pyridine to afford moderate to quantitative yields of the corresponding hindered 3-aryl-3-phenylthiochroman-4-one derivatives. Removal of the phenylthio group by oxidation with dimethyldioxirane led to the corresponding isoflavones and 2-p-methoxyphenylisoflavones, and by reduction with a large excess of nickel boride to the isoflavanones and 2-(4′-anisyl)-isoflavanones respectively. In the 2-p-methoxyphenyl series the nickel boride reduction of the compounds bearing ortho-substituted 3-aryl groups gave the chalcones which were recyclised under basic catalysis.
- Donnelly, Dervilla M. X.,Fitzpatrick, Brendan M.,O'Reilly, Bernadette A.,Finet, Jean-Pierre
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p. 7967 - 7976
(2007/10/02)
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- A general method for the synthesis of isoflavones by oxidative rearrangement of flavanones using thallium (III) perchlorate
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Oxidation of flavanones with thallium(III) perchlorate in acetonitrile or dimethoxyethane leads to 2,3-aryl migration providing a general method for the synthesis of isoflavones having electron relasing as well as electron withdrawing substituents at C2-aryl ring and the mechanism in relaltion to in vivo is discussed.
- Singh, Om V.,Kapil, Randhir S.
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p. 911 - 915
(2007/10/02)
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- Ligand Coupling Route to Isoflavanones and Isoflavones
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Phenylation of 3-phenylsulfonylchroman-4-ones using Ph3BiCO3 leading to the synthesis of isoflavanones and isoflavones is reported.
- Santhosh, K. C.,Balasubramanian, K. K.
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p. 224 - 225
(2007/10/02)
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- New procedures for the preparation of isoflavones with unsubstituted ring A
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Isoflavones with unsubstituted ring A have been synthesized either by the ring closure of 2-hydroxydeoxybenzoins or by the dehydroxylation of 7-hydroxyisoflavones. 7-Mercaptoisoflavones have also been prepared.
- Levai,Sebok
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p. 1735 - 1750
(2007/10/02)
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- Oxidation of Flavanones using Thallium(III) Salts: A New Route for the Synthesis of Flavones and Isoflavones
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When treated with thallium(III) acetate in acetic acid or acetonitrile, flavanones undergo facile dehydrogenation to afford flavones whereas, upon treatment with thallium(III) toluene-p-sulfonate or thallium(III) nitrate in propionitrile or acetonitrile, respectively, they undergo oxidative 2,3-aryl migration to give isoflavones in high yield.
- Khanna, Mahavir S.,Singh, Om V.,Garg, Chandra P.,Kapoor, Ram P.
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p. 2565 - 2568
(2007/10/02)
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- Expedient Synthesis of Polyhydroxyisoflavones
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A general and direct synthesis of polyhydroxy isoflavones (3-phenyl-4H-1-benzopyran-4-ones) starting from the corresponding unprotected phenols and arylacetic acids is described.The aryl rings may carry additional alkyl, methoxy and/or halogeno groups.Intermediate polyhydroxydeoxybenzoins (1,2-diphenylethanones) can also be isolated in good yields.
- Waehaelae, Kristiina,Hase, Tapio A.
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p. 3005 - 3008
(2007/10/02)
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- ONE-STEP CONVERSION OF FLAVANONES INTO ISOFLAVANONES: A NEW FACILE BIOMIMETIC SYNTHESIS OF ISOFLAVONES
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One-step chemical conversion of flavanones into isoflavones by use of thallium trinitrate (TTN) is reported, and the mechanism of a 2,3-aryl migration in this reaction is discussed in relation to in vivo rearrangement process of flavanone precursors in the isoflavone biosynthesis.
- Kinoshita, Takeshi,Ichinose, Koji,Sankawa, Ushio
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p. 7355 - 7356
(2007/10/02)
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- Oxidative 1,2-aryl rearrangement in flavanones using thallium(III) p-tolylsulphonate (TTS): A new useful route to isoflavones
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Oxidation of flavanones using thallium(III) p-tolylsulphonate (prepared in situ by the reaction of thallium(III) acetate and p-toluene sulphonic acid) in propionitrile leads to 1,2-aryl shift providing a new useful route to the synthesis of isoflavones.
- Singh,Garg,Kapoor
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p. 2747 - 2750
(2007/10/02)
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- Chemotherapeutic agents
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A method of treating or preventing viral infections, in particular rhinovirus infections comprising the administration of an effective amount of a 2-phenyltetralin derivative or a heterocyclic analogue thereof. Pharmaceutical compositions containing these compounds, and some novel compounds are also disclosed.
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- FACILE SYNTHESIS OF ISOFLAVONES BY THE CROSS-COUPLING REACTION OF 3-IODOCHROMONE WITH ARYLBORONIC ACIDS
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We describe a convenient preparation of isoflavones by the cross-coupling reactions of 3-iodo-chromone (1) with arylboronic acids (2) catalyzed by tetrakis(triphenylphosphine)palladium(0).KEYWORDS isoflavone; 3-iodochromone; phenylboronic acid; cross-coupling reaction; tetrakis(triphenylphosphine)palladium
- Yokoe, Ichiro,Sugita, Yoshiaki,Shirataki, Yoshiaki
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p. 529 - 530
(2007/10/02)
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- Intramolecular Ketene Cycloadditions. Synthesis of Isoflavones and 3-Aroylbenzofurans
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The conversion of 2-(carboxyalkoxy)benzils to the corresponding phenoxyketenes to an intramolecular ketene cycloaddition to ultimately yield isoflavones and/or 3-aroylbenzofurans.The ketenes may be generated by the classical dehydrochlorination of the acid chloride or by using Perkin reaction conditions, sodium acetate in refluxing acetic anhydride.The initial cycloaddition products are the corresponding β-lactones, which may decarboxylate to the isolated isoflavones and/or 2-aroylbenzofurans.The product distributions are dependent upon the substitution pattern in the orginal benzil acids.
- Brady, William T.,Gu, Yi-Qi
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p. 1353 - 1356
(2007/10/02)
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