cas 3929-47-3, 3-(3,4-DIMETHOXYPHENYL)-1-PROPANOL

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In silico design and synthesis of N-arylalkanyl 2-naphthamides as a new class of non-purine xanthine oxidase inhibitors
A series of N-arylalkanyl 2-naphthamides (Xa~e), which were predicted from virtual molecular docking on a built xanthine oxidase template as potential inhibitors, were synthesized. Their inhibitory activity against xanthine oxidase was assayed. Among these prepared, compounds Xb (IC50 13.6?μM), Xc (IC50 13.1?μM), and Xd (IC50 12.5?μM) showed comparable inhibitory activity to allopurinol (IC50 22.1?μM). The in vitro assay result correlated well with molecular docking scores, ΔG?=??16.99, ?17.66, and ?17.13 Kcal/mol, respectively. On the potassium oxonate-induced hyperuricemic mice model, oral administration of Xc-Ac (40 mg/ Kg), the per-O-acetylated Xc, could reduce the blood uric acid level by 60% in comparison to the normal control group and is statistically significant (p .01) while compared with the hyperuricemic mice group.
Ho, Sheau Ling,Lin, Ching-Ting,Lee, Shoei-Sheng
p. 789 - 801
(2021/01/12)

DOPAMINE RECEPTOR D1 AGONISTS AND METHODS OF USE
Described herein are small molecule agonists of dopamine receptor D1 that inhibit YAP/TAZ, compositions, and methods of using these compounds and compositions.
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(2021/02/05)

Synthesis and Studies of Potential Inhibitors of CD73 Based on a Triazole Scaffold
The ecto-5′-nucleotidase CD73 is involved in the production of immunosuppressive adenosine in the tumoral microenvironment and recently became a validated target in immuno-oncology. To avoid formation of CD73-produced adenosine, several series of potential inhibitors of the target enzyme based on a triazole scaffold were synthetized and evaluated on recombinant purified hCD73 and in cell-based assays.
Braka, Abdenour,Chaloin, Laurent,Cros-Perrial, Emeline,Grosjean, Félix,Jordheim, Lars Petter,Mathé, Christophe,Peyrottes, Suzanne,Uttaro, Jean-Pierre
supporting information

(2021/12/14)

Copper-Catalyzed Intermolecular Enantioselective Radical Oxidative C(sp3)?H/C(sp)?H Cross-Coupling with Rationally Designed Oxazoline-Derived N,N,P(O)-Ligands
The intermolecular asymmetric radical oxidative C(sp3)?C(sp) cross-coupling of C(sp3)?H bonds with readily available terminal alkynes is a promising method to forge chiral C(sp3)?C(sp) bonds because of the high atom and step economy, but remains underexplored. Here, we report a copper-catalyzed asymmetric C(sp3)?C(sp) cross-coupling of (hetero)benzylic and (cyclic)allylic C?H bonds with terminal alkynes that occurs with high to excellent enantioselectivity. Critical to the success is the rational design of chiral oxazoline-derived N,N,P(O)-ligands that not only tolerate the strong oxidative conditions which are requisite for intermolecular hydrogen atom abstraction (HAA) processes but also induce the challenging enantiocontrol. Direct access to a range of synthetically useful chiral benzylic alkynes and 1,4-enynes, high site-selectivity among similar C(sp3)?H bonds, and facile synthesis of enantioenriched medicinally relevant compounds make this approach very attractive.
Gu, Qiang-Shuai,Guo, Kai-Xin,Li, Zhong-Liang,Liu, Lin,Liu, Xin-Yuan,Tian, Yu,Yang, Chang-Jiang,Ye, Liu
supporting information
p. 26710 - 26717
(2021/11/18)

Cleavage of aryl-ether bonds in lignin model compounds using a Co-Zn-beta catalyst
Efficient cleavage of aryl-ether linkages is a key strategy for generating aromatic chemicals and fuels from lignin. Currently, a popular method to depolymerize native/technical lignin employs a combination of Lewis acid and hydrogenation metal. However, a clear mechanistic understanding of the process is lacking. Thus, a more thorough understanding of the mechanism of lignin depolymerization in this system is essential. Herein, we propose a detailed mechanistic study conducted with lignin model compounds (LMC) via a synergistic Co-Zn/Off-Al H-beta catalyst that mirrors the hydrogenolysis process of lignin. The results suggest that the main reaction paths for the phenolic dimers exhibiting α-O-4 and β-O-4 ether linkages are the cleavage of aryl-ether linkages. Particularly, the conversion was readily completed using a Co-Zn/Off-Al H-beta catalyst, but 40% of α-O-4 was converted and β-O-4 did not react in the absence of a catalyst under the same conditions. In addition, it was found that the presence of hydroxyl groups on the side chain, commonly found in native lignin, greatly promotes the cleavage of aryl-ether linkages activated by Zn Lewis acid, which was attributed to the adsorption between Zn and the hydroxyl group. Followed by the cobalt catalyzed hydrogenation reaction, the phenolic dimers are degraded into monomers that maintain aromaticity. This journal is
Chang, Hou-Min,Dou, Xiaomeng,Jameel, Hasan,Jiang, Xiao,Li, Wenzhi,Zhu, Chaofeng
p. 43599 - 43606
(2020/12/25)

Structural optimization of natural product nordihydroguaretic acid to discover novel analogues as AcrB inhibitors
Drug efflux pumps confer multidrug resistance to dangerous bacterial pathogens which makes these proteins promising drug targets. Herein, we present initial chemical optimization and structure-activity relationship (SAR) data around a previously described efflux pump inhibitor, nordihydroguaretic acid (NDGA). Four series of novel NDGA analogues that target Escherichia coli AcrB were designed, synthesized and evaluated for their ability to potentiate the activity of antibiotics, to inhibit AcrB-mediated substrate efflux and reduce off-target activity. Nine novel structures were identified that increased the efficacy of a panel of antibiotics, inhibited drug efflux and reduced permeabilization of the bacterial outer and inner membranes. Among them, WA7, WB11 and WD6 possessing broad-spectrum antimicrobial sensitization activity were identified as NDGA analogues with favorable properties as potential AcrB inhibitors, demonstrating moderate improvement in potency as compared to NDGA. In particular, WD6 was the most broadly active analogue improving the activity of all four classes of antibacterials tested.
Alenzy, Rawaf,Liu, Xingbang,Ma, Shutao,Ma, Yingang,Mowla, Rumana,Polyak, Steven W.,Song, Di,Teng, Yuetai,Venter, Henrietta,Wang, Yinhu
(2019/12/24)

BIOISPIRED PROTEASOME ACTIVATORS WITH ANTIAGEING ACTIVITY
The present invention relates to novel bio-inspired hybrid compounds of formula I which act as proteasome activators and exhibit anti-ageing activity, as well as methods for their synthesis. These hybrid compounds combine the structural features of hydroxytyrosol and the natural antioxidant vitamin E or its bioisosteres in one molecular scaffold. The compounds of formula I, which include structural proteasome activators (activation by stereochemical interaction), can be used in the production of anti-ageing products, such as cosmetic preparations. Additionally, they can be used in conditions and diseases where the proteasome is down-regulated, as well as proteasome-activation control compounds.
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(2019/10/01)

EC18 as a Tool to Understand the Role of HCN4 Channels in Mediating Hyperpolarization-Activated Current in Tissues
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are membrane proteins encoded by four genes (HCN1-4) and widely distributed in the central and peripheral nervous system and in the heart. HCN channels are involved in several physiological functions, including the generation of rhythmic activity, and are considered important drug targets if compounds with isoform selectivity are developed. At present, however, few compounds are known, which are able to discriminate among HCN channel isoforms. The inclusion of the three-methylene chain of zatebradine into a cyclohexane ring gave a compound (3a) showing a 5-fold preference for HCN4 channels, and ability to selectively modulate Ih in different tissues. Compound 3a has been tested for its ability to reduce Ih and to interact with other ion channels in the heart and the central nervous system. Its preference for HCN4 channels makes this compound useful to elucidate the contribution of this isoform in the physiological and pathological processes involving hyperpolarization-activated current.
Romanelli, Maria Novella,Del Lungo, Martina,Guandalini, Luca,Zobeiri, Mehrnoush,Gy?keres, András,árpádffy-Lovas, Tamás,Koncz, Istvan,Sartiani, Laura,Bartolucci, Gianluca,Dei, Silvia,Manetti, Dina,Teodori, Elisabetta,Budde, Thomas,Cerbai, Elisabetta
supporting information
p. 584 - 589
(2019/02/27)

Total Synthesis and Evaluation of B-Homo Palmatine and Berberine Derivatives as p300 Histone Acetyltransferase Inhibitors
Palmatine and berberine, structurally similar isoquinoline alkaloids exhibiting a broad range of biological activities, were recently found to inhibit p300 histone acetyltransferase (HAT), a potential therapeutic target for treating transcriptional activator-driven malignancies and diseases. Here, we report the first total synthesis of B-homo palmatine (11a) and berberine (11b) derivatives, which were synthesized from 3,4-dimethoxybenzaldehyde (1a) and benzo[d][1,3]dioxole-5-carbaldehyde (1b) in nine steps in 13.8 and 16.9 % overall yields, respectively. A number of other new B-homo palmatine and berberine derivatives were also prepared. These derivatives display good inhibitory activity against p300 HAT; compound 12a manifests the most potent inhibition with an IC50 value of 0.42 μm. Cell-based assays revealed that 12a exhibits certain inhibitory activity against HCG27, HT1080, and Z-138 cell lines, and no visible activity towards other cancer cell lines tested, reflecting that 12a has low cytotoxicity and acts against some types of cancer cells.
Yang, Zhongzhen,Zhang, Yong,Chen, Xin,Li, Weijian,Li, Guo-Bo,Wu, Yong
p. 1041 - 1052
(2018/03/06)

Synthesis, in vitro and in silico evaluation of diaryl heptanones as potential 5LOX enzyme inhibitors
A new series of diaryl heptanones (12a-q) were synthesized and their structures were confirmed by its 1H, 13C NMR and Mass spectral data. These analogs were evaluated for their anti-oxidant activity and potential to inhibit 5-lipoxygenase. Compounds 12k and 12o showed potent in vitro 5-lipoxygenase enzyme inhibitory activity with IC50 values of 22.2, 21.5 μM, which are comparable to curcumin (24.4 μM). Further they also have shown significant antioxidant activity. Molecular docking studies clearly showed correlation between binding energy and potency of these compounds.
Meka, Bharani,Ravada, Suryachandra Rao,Muthyala, Murali Krishna Kumar,Kurre, Purna Nagasree,Golakoti, Trimurtulu
p. 408 - 421
(2018/07/13)

Highly sulphated cellulose: a versatile, reusable and selective desilylating agent for deprotection of alcoholic TBDMS ethers
A mild, efficient and rapid protocol was developed for the deprotection of alcoholic TBDMS ethers using a recyclable, eco-friendly highly sulphated cellulose sulphate acid catalyst in methanol. This acid catalyst selectively cleaves alcoholic TBDMS ethers in bis-TBDMS ethers containing both alcoholic and phenolic TBDMS ether moieties.
Dachavaram, Soma Shekar,Penthala, Narsimha R.,Calahan, Julie L.,Munson, Eric J.,Crooks, Peter A.
p. 6057 - 6062
(2018/09/06)

High B ring berberine and palmatine derivative synthesis and as the use of reducing blood sugar (by machine translation)
The present invention provides a new class of high B ring berberine and palmatine derivative, as shown in the structural formula is shown as: The invention also provides a high B ring berberine and palmatine derivative of preparation and use. The potency test Certificate, the compounds of the invention having good in-vitro hypoglycemic effect, part of the superior to the berberine hydrochloride positive control. The invention high B ring berberine and palmatine derivative potency is prominent, there may be clinical provides a new choice of drug use for. (by machine translation)
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Paragraph 0007; 0061; 0067

(2018/06/26)

Synthesis of 2-tetralone derivatives by Bi(OTf)3-catalyzed intramolecular hydroarylation/isomerization of propargyl alcohols
Compared to 1-tetralones, 2-tetralones are expensive, less stable, and difficult to synthesize. A concise Bi-catalyzed method was developed for the synthesis of 2-tetralones from 5-phenylpent-1-yn-3-ol derivatives. Diverse 2-tetralones were obtained in moderate to good yields under mild conditions.
Yun, Jihee,Park, Jungmin,Kim, Jaehyun,Lee, Kooyeon
p. 1045 - 1048
(2015/02/19)

Selective Ether/Ester C-O Cleavage of an Acetylated Lignin Model via Tandem Catalysis
Selective ether/ester C-O bond hydrogenolysis of an acetylated lignin model is achieved using a thermodynamically leveraged tandem catalytic strategy. Acetylation serves to (1) solubilize both lignin and lignin models and to (2) modify the reactivity of pendant hydroxy groups to promote more selective C-O cleavage.
Lohr, Tracy L.,Li, Zhi,Marks, Tobin J.
p. 7004 - 7007
(2015/11/24)

Mild heterogeneous palladium-catalyzed cleavage of β-o-4'-ether linkages of lignin model compounds and native lignin in air
A mild and robust heterogeneous palladium-catalyzed C - O bond cleavage of 2-aryloxy-1-arylethanols using formic acid as reducing agent in air was developed. The cleaved products were isolated in 92-98 % yield; and by slightly varying the reaction conditions, a ketone, an alcohol, or an alkane can be generated in near-quantitative yield. This reaction is applicable to cleaving the β-O-4'-ether bond found in lignin polymers of different origin. The reaction was performed on a lignin polymer model to generate either the monomeric aryl ketone or alkane in a quantitative yield. Moderate depolymerization was achieved with native lignin at similar reaction conditions. Mechanistic studies under kinetic control indicate that an initial palladium-catalyzed dehydrogenation of the alcohol is followed by insertion of palladium to an enol equivalent. A palladium-formato complex reductively cleaves the palladium-enolate complex to generate the ketone. Copyright
Galkin, Maxim V.,Sawadjoon, Supaporn,Rohde, Volker,Dawange, Monali,Samec, Joseph S. M.
p. 179 - 184
(2014/01/23)

PYRIMIDINE DERIVATIVES FOR THE TREATMENT OF VIRAL INFECTIONS
This invention relates to pyrimidine derivatives, processes for their preparation, pharmaceutical compositions, and their use in treating viral infections such as HCV or HBV.
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(2014/03/21)

Improved synthesis of natural ester sintenin and its analogues via Wittig reaction
The synthesis of a cytotoxic natural ester sintenin (7a) and twenty eight of its analogues including nitrogen-containing heterocyclic indole moiety (7b-7t), saturated (10a-10d) and unsaturated (10e-10h) amides were carried out by convenient route via one-pot Wittig reaction in aqueous medium with improved yield. A systematic structure activity relationship of sintenin ester was designed by chemically modified derivatives in order to get better cytotoxicity.
Sharma, Mukul,Rajesh, U. Chinna,Rawat, Diwan S.
p. 1853 - 1860
(2014/01/17)

A natural product inspired tetrahydropyran collection yields mitosis modulators that synergistically target CSE1L and tubulin
A Prins cyclization between a polymerbound aldehyde and a homoallylic alcohol served as the key step in the synthesis of tetrahydropyran derivatives. A phenotypic screen led to the identification of compounds that inhibit mitosis (as seen by the accumulation of round cells with condensed DNA and membrane blebs; see picture). These compounds were termed tubulexins as they target the CSE1L protein and the vinca alkaloid binding site of tubulin.
Voigt, Tobias,Gerding-Reimers, Claas,Tran, Tuyen Thi Ngoc,Bergmann, Sabrina,Lachance, Hugo,Sch?lermann, Beate,Brockmeyer, Andreas,Janning, Petra,Ziegler, Slava,Waldmann, Herbert
supporting information
p. 410 - 414
(2013/02/23)

O-alkyl-N-acyl-N-phenylhydroxylamines as photochemical alkoxy radical precursors
A simple and efficient technique for the photolysis of alkoxy radical precursors is developed. Irradiation of O-alkyl-N-acyl-N-phenylhydroxylamines, as representative alkoxy radical precursors, with ultraviolet light (254 nm) results in homolytic N-O bond cleavage to generate singlet alkoxy and acylaminyl caged radical pairs. These radicals, depending on the solvent employed, either escape from the cage to form fragmentation products, or undergo in-cage reactions to produce photorearrangement products. The homolytic cleavage of the N-O bond is analyzed using time-dependent density functional theory calculations. The nature of the N-acyl substituent on the O-alkyl-N-acyl-N- phenylhydroxylamines is shown to influence their ability to generate radicals. Furthermore, identification and trapping of the alkoxy radicals is demonstrated. Georg Thieme Verlag Stuttgart · New York.
Chowdhury, Nilanjana,Anoop, Anakuthil,Singh, N.D. Pradeep
experimental part
p. 1745 - 1754
(2012/07/27)

PYRIMIDINE DERIVATIVES FOR THE TREATMENT OF VIRAL INFECTIONS
This invention relates to pyrimidine derivatives, processes for their preparation, pharmaceutical compositions, and their use in treating viral infections such as HCV or HBV.
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(2012/10/18)

Radical addition of silanes to alkenes followed by oxidation
Phenyldimethylsilane and trichlorosilane are shown to undergo efficient radical hydrosilylation reactions, on reaction with various alkenes, using triethylborane as the initiator. Adducts from the trichlorosilane reactions can be oxidised to afford alcohols in good yields. This two-step process leads to the anti-Markovnikov hydration of alkenes. Georg Thieme Verlag Stuttgart · New York.
Palframan, Matthew J.,Parsons, Andrew F.,Johnson, Paul
experimental part
p. 2811 - 2814
(2012/01/06)

Hydrogenolysis of the cyclopropyl group into an isopropyl group in the presence of a platinum catalyst and hydrobromic acid
Reduction of cyclopropylmethylamines proceeded under mild reaction conditions in the presence of platinum (IV) oxide catalyst and hydrobromic acid at rt, providing isobutylamines and no linear butylamines. The ring cleavage reaction was widely applicable to cyclopropane rings in various compounds such as N-cyclopropylalkyl, O-cyclopropylalkyl, and C-cyclopropylalkyl derivatives. Although unactivated cyclopropane rings were also cleaved, the cyclobutane ring was tolerated under the same reaction conditions.
Fujii, Hideaki,Okada, Kayoko,Ishihara, Marina,Hanamura, Shinichi,Osa, Yumiko,Nemoto, Toru,Nagase, Hiroshi
experimental part
p. 10623 - 10630
(2010/02/27)

Cobalt(II) chloride hexahydrate-diisopropylamine catalyzed mild and chemoselective reduction of carboxylic esters with sodium borohydride
The cobalt-catalyzed reduction of unsaturated α-cyano carboxylic esters using sodium borohydride (NaBH4) leads to the corresponding saturated cyano alcohols in high yields. In particular, the new catalytic system cobalt(II) chloride-diisopropylamine in combination with NaBH4 showed excellent activity in the chemoselective reduction of a variety of carboxylic esters to their corresponding alcohols in good to excellent yields under mild conditions. Georg Thieme Verlag Stuttgart.
Jagdale, Arun R.,Paraskar, Abhimanyu S.,Sudalai, Arumugam
experimental part
p. 660 - 664
(2009/07/03)

A novel and efficient synthesis of dihydrexidine
An efficient synthesis of the dopamine D1 selective full agonist dihydrexidine has been achieved in high yields and requiring no chromatographic separations via a facilitated intramolecular Henry cyclization of a (nitropropyl)benzophenone and subsequent diastereomerically selective reduction of the resulting tricyclic ni- troalkene. Georg Thieme Verlag Stuttgart.
Cueva, Juan Pablo,Nichols, David E.
experimental part
p. 715 - 720
(2009/09/06)

The synthesis of Sintenin, a new cytotoxic ester from Piper sintenense
A first short synthesis of Sintenin 1 has been accomplished starting from 3,4-dimethoxybenzaldehyde 2 utilizing Knoevenagal condensation and catalytic hydrogenation using Pd/C as key reactions, in almost quantitative yield. The identity with the naturally occurring compound Sintenin was established on the basis of 1H NMR and 13C NMR data.
Sharma,Sharma,Rathee, Raman
p. 938 - 939
(2007/10/03)

ARYL-QUINAZOLINE/ARYL-2AMINO-PHENYL METHANONE DERIVATIVES
A compound of formula (I): wherein R1, R2, R3 and Y are as defined herein, or a pharmaceutically-acceptable and -cleavable ester, or acid addition salt thereof, useful for promoting the release of parathyroid hormone, e.g. for preventing or treating bone conditions which are associated with increased calcium depletion or resorption or in which stimulation of bone formation and calcium fixation in the bone is desirable.
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(2008/06/13)

Sodium borohydride and vinyl triflates of α-keto esters: A new combination toward monoalkylated 1,2-diols
NaBH4 converts a range of methyl 2-trifluoromethanesulfonyloxy 3-substituted propenoates to the corresponding monoalkylated 1,2-diols smoothly with total regiocontrol.
Dalla, Vincent,Decroix, Bernard
p. 1657 - 1660
(2007/10/03)

High hypolipidemic activity of saturated side-chain α-asarone analogs
With the aim of evaluating the pharmacophore potential of the side chain of α-asarone (1) regarding its high hypolipidemic activity, the series of derivatives 7a-7e, and 11-13 were evaluated pharmacologically. For the hydrocarbon compounds 7a-7e, with a variable-size side chain, significant decreases in serum cholesterol, LDL-cholesterol, and triglyceride levels and significant increases in HDL-cholesterol levels were observed in mice. The small-size side-chain derivatives were even more active than 1 in reducing cholesterol. The results suggested that the length and saturated character of the side chain seem to be a key feature in improving hypolipidemic activity of α-asarone (1) analogs.
Cruz, Adriana,Garduno, Leticia,Salazar, Maria,Martinez, Elizdath,Diaz, Francisco,Chamorro, German,Tamariz, Joaquin
p. 587 - 595
(2007/10/03)

Hypervalent iodine(III)-induced intramolecular cyclization of α-(aryl)alkyl-β-dicarbonyl compounds: A convenient synthesis of benzannulated and spirobenzannulated compounds
A novel hypervalent iodine(III)-induced direct intramolecular cyclization of α-(aryl)alkyl-β-dicarbonyl compounds has been described. Both meta- and para-substituted phenol ether derivatives containing acyclic or cyclic 1,3-dicarbonyl moieties at the side chain undergo this reaction in a facile manner. The reactions afford benzannulated and spirobenzannulated compounds that are of biological importance. The reaction is found to be general, mild, and high yielding. The mechanism of the reaction has been shown to involve a cation radical intermediate.
Arisawa,Ramesh,Nakajima,Tohma,Kita
p. 59 - 65
(2007/10/03)

Hypervalent iodine(III)-induced intramolecular cyclization reaction of substituted phenol ethers with an alkyl azido side-chain: A novel and efficient synthesis of quinone imine derivatives
Novel and efficient syntheses of quinone imine ketals (2aj) and quinone imines (4ah) from substituted phenol ethers (1ak) bearing an alkyl azido side-chain using the combination of hypervalent iodine(III) reagent, phenyliodine(III) bis(trifluoroacetate) (PIFA) and trimethylsilyl trifluoromethanesulfonate (TMSOTf), have been developed.
Kita, Yasuyuki,Egi, Masahiro,Ohtsubo, Makoto,Saiki, Toyokazu,Okajima, Akiko,Takada, Takeshi,Tohma, Hirofumi
p. 241 - 245
(2007/10/03)

Utilization of the intramolecular cycloaddition-cationic π-cyclization of an isomunchnone derivative for the synthesis of (±)-lycopodine
A new annulation sequence leading to the tetracyclic skeleton of the Lycopodium family of alkaloids is effected by using the tandem cycloaddition-cationic π-cyclization reaction of an isomunchnone dipole as the key strategic element. Synthesis of the required α-diazo imide precursor involved treating 5-methylcyclohex-2-en-1-one with the organocopper reagent derived from 3-methoxybenzyl chloride in the presence of chlorotrimethylsilane. Ozonolysis of the resulting silyl enol ether followed by a Wittig reaction and conversion to the desired α-diazo imide was carried out using standard malonylacylation and diazotization procedures. Treatment of the α-diazo imide with rhodium(II) perfluorobutyrate afforded a transient 1,3-dipole which subsequently cycloadded across the tethered π-bond. The resulting cycloadduct was treated with BF39.2AcOH to give a rearranged tetracyclic compound derived from a Pictet-Spengler-type cyclization of an N-acyliminium ion. The rearranged product was subsequently converted into a key intermediate previously used for the synthesis of (±)-lycopodine.
Padwa,Brodney,Marino J.P.,Sheehan
p. 78 - 87
(2007/10/03)

Intramolecular regioselective insertion into unactivated prochiral carbon-hydrogen bonds with diazoacetates of primary alcohols catalyzed by chiral dirhodium(II) carboxamidates. Highly enantioselective total synthesis of natural lignan lactones
Intramolecular insertion into unactivated prochiral C-H bonds of 3-aryl-1-propyl diazoacetates catalyzed by dirhodium(II) tetrakis[methyl 1-(3-phenyl propanoyl)imidazolidin-2-one-4(R or S)-carboxylate], Rh2(4R-MPPIM)4 or Rh2(4S-MPPIM)4, occurs in 91-96% ee and with virtually complete regiocontrol for the formation of β-benzyl-γ-butyrolactones. This methodology has been applied to the total synthesis of dibenzylbutyrolactone lignans (-)- and (+)-enterolactone, (-)- and (+)-hinokinin, and (+)-arctigenin from substituted cinnamic acids in 19-27% overall yields. Aryltetralin lignan (+)-isodeoxypodophyllotoxin was prepared from the reactant 3,4-(methylenedioxy)cinnamic acid in 36% yield overall, and the lactone precursor to (+)-isolauricerisinol was formed in 96.5% ee and 23% yield overall. Applications of the chiral Rh2(MPPIM)4 catalysts to fully aliphatic systems resulting in the formation of β-substituted-γ-butyrolactones with high regiocontrol and with 93-96% ee have demonstrated the generality of this methodology. A model that provides accurate predictions of β-substituted-γ-butyrolactone absolute configurations in these asymmetric metal carbene transformations is described.
Bode,Doyle,Protopopova,Zhou
p. 9146 - 9155
(2007/10/03)

Reactions of Lignin-related Cinnamaldehydes and Cinnamyl Alcohols with Borane and Sodium Tetrahydridoborate
Hydroboration/oxidation of 3-(3,4-dimethoxyphenyl)-2-propen-1-ol gives a mixture of 1-(3,4-dimethoxyphenyl)-1,3-propanediol, 3-(3,4-dimethoxyphenyl)-1,2-propanediol and 3-(3,4-dimethoxyphenyl)-1-propanol; the same compounds are obtained as by-products when the lignin model 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)-1,3-propanediol is synthesized by hydroboration/oxidation of α-(2-methoxyphenoxy)-3,4-dimethoxycinnamic acid. (Z)-3-(3,4-dimethoxyphenyl)-2-propen-1-ol and (E0-α-(2-methoxy-phenoxy)-3,4-dimethoxycinnamic acid give compratively large amounts of 3-(3,4-dimethoxyphenyl)-1,3-propanediol.The results support the view that the by-products are formed via 3-(3,4-dimethoxyphenyl)-2-propen-1-ol.Small amounts of the same by-products are obtained on tetrahydridoborate reduction of (E)-3-(3,4-dimethoxyphenyl)propenal .Analogous results were obtained with (E)-3-phenylpropenal.Models representative of lignin units of the cinnamaldehyde and cinnamyl alcohol types have been prepared and precise 1H NMR spectral data (400 MHz, 300 K) for the compounds are reported.
Li, Shiming,Lundquist, Knut
p. 64 - 67
(2007/10/02)

The Enantiospecific Nicholas Reaction
The enantiospecific Nicholas reaction, i.e. cobalt-promoted Friedel-Crafts reaction leading from chiral reactant to chiral product, was demonstrated for the first time. - Key Words: Nicholas reaction; enantiospecific; cobalt-stabilized carborations; 1-ethynyltetralin
Muehldorf, Alexander V.,Guzman-Perez, Angel,Kluge, Arthur F.
p. 8755 - 8758
(2007/10/02)

CINNAMIC ACID BRIDGES BETWEEN CELL WALL POLYMERS IN WHEAT AND PHALARIS INTERNODES
A method has been devised for the quantitative determination of cinnamic acids participating in ester-ether bridges between cell wall polymers based on the different reactivities of free carboxylic acids and their esters towards borohydride reductants and the different susceptibilities of cinnamic acid ester and benzyl ether linkages to alkaline treatments.Lignin-poylsaccharide containing fractions extracted with dioxane-H2O from cell walls of wheat (Triticum aestivum) and phalaris (phalaris aquatica) internodes are hydrogenated using a Pd/C catalyst at room temperature to convert cinnamic acids to their corresponding dihydrocinnamic acids.The sample is subsequently reduced with LiBH4 in ether-toluene to convert ester-linked dihydrocinnamates to their corresponding alcohols, hydrolysed with 4 M NaOH at 170 deg, and the dihydrocinnamic acid derivatives released from their etherified forms determined by GC.Using model compounds it was shown that these reactions proceeded quantitatively.The results indicate that all of the etherified ferulic acid in the dioxane-H2O-soluble fractions of walls of wheat and phalaris internodes is also ester-linked.It has been calculated that there are nine to 10 ferulic acid ester-ether bridges for every 100 C6-C3 lignin monomers. p-Coumaric acid is not involved in ester-ether bridges. Key Word Index - Triticum aestivum; Phalaris aquatica; Gramineae; lignin; polysaccharide; p-coumaric acid; ferulic acid; esterified cinnamic acid; etherified cinnamic acid.
Lam, Thi Bach Tuyet,Iiyama, Kenji,Stone, Bruce A.
p. 1179 - 1184
(2007/10/02)

1,4-bis (dihydroxyphenyl) butane and analogs
A grignard synthesis of pharmacologically active 1,4-bis(dihydroxyphenyl)butane and analogs, as well as novel intermediates, is provided, comprising preparing a grignard reagent preferably, a 3,4-dialkoxyphenyl propyl magnesium bromide, which may be reacted with carbonyl compounds to form intermediates of desired end products, said carbonyl compounds preferably being 3,4-dialkoxybenzaldehydes. The resulting alcohol is converted to a corresponding ether or siloxy compound, at the carbonyl site. The oxy-substituent is cleaved off; and the benzene ring or rings dealkylated to leave hydroxy substituents on the rings.
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(2008/06/13)

Search for new Ca++ antagonists. Lipophilic oximes and phosphonates
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Bellucci,Teodori,Gualtieri
p. 730 - 744
(2007/10/02)

OLEFIN SATURATION AND ACID REDUCTION OF 3,4-DIMETHOXYCINNAMIC ACID AND DERIVATIVES BY PHANEROCHAETE CHRYSOSPORIUM
The white rot fungus Phanerochaete chrysosporium metabolized 3,4-dimethoxycinnamic acid in shaking and nitrogen sufficient cultures.Metabolites identified included 3-(3,4-dimethoxyphenyl)propionic acid, dimethoxycinnamyl alcohol and 3-(3,4-dimethoxyphenyl)-1-propanol.Significantly smaller amounts of veratryl and vanillyl alcohol were also present.The abundance of the propionic acid and the propanol as metabolic products indicate that olefin saturation and acid reduction are important reactions catalysed under these conditions.Metabolites identified from the metabolism of 3-(3,4-dimethoxyphenyl)-propionic acid included the above 1-propanol as well as veratryl and vanillyl alcohol; the identification of these benzyl alcohol derivatives as metabolites suggests that α,β-bond cleavage of this substrate was preceded by alkane hydroxylation at the α-position.Key Word Index-Phanerochaete chrysosporium; basidiomycete; dimethoxycinnamic acid; ferulic acid; veratryl alcohol; acid reduction; olefin saturation; metabolism
Enoki, Akio,Yajima, Yasuo,Gold, Michael H.
p. 1543 - 1546
(2007/10/02)

The Synthesis of 1-Haloalkyl-1,3,4,5-tetrahydro-2-benzoxepins
Short, efficient routes to several 7,8-dimethoxy-1-haloalkyl-1,3,4,5-tetrahydro-2-benzoxepins were developed.These benzoxepins were prepared by the Lewis acid catalyzed condensation of the acetals of chloropropionaldehyde or bromoacetaldehyde with 3-(3,4-dimethoxyphenyl)-1-propanol.This condensation was facilitated by methyl substitution on the propanol.In an alternate route, ethyl 3-(3,4-dimethoxyphenyl)propanoate was acylated with 3-chloropropionyl chloride.The adduct was reduced with lithium aluminum hydride.The resultant 3-propanol was dehydrated to the corresponding tetrahydrobenzoxepin.By these two general routes, 7,8-dimethoxy-1,3,4,5-tetrahydro-2-benzoxepins were produced which were substituted by hydrogen or methyl at benzoxepin C-4 and chloroethyl or bromomethyl at benzoxepin C-1.
TenBrink, Ruth E.,McCall, John M.
p. 821 - 824
(2007/10/02)

1-[(Ethoxyamino)methyl]-1,3,4,5-tetrahydro-7,8-dimethoxy-2-benzoxepins: A new class of antianaphylactic agents
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TenBrink,McCall,Johnson
p. 1058 - 1060
(2007/10/02)