Letters in Organic Chemistry

ISSN: 1570-1786

Letters in Organic Chemistry
Volume 5, Number 8, December 2008


Contents



Enantioselective Michael Addition of Dimethyl Malonate to (E)-β- Nitrostyrenes Catalyzed by Cinchona Alkaloids Under Solvent- Free Condition Pp. 602-606
Francesco Fringuelli, Luca Castrica, Ferdinando Pizzo and Luigi Vaccaro
[Abstract] [Full Text Article]


Efficient Microwave Solvent-Free Synthesis of Flavones, Chromones, Coumarins and Dihydrocoumarins Pp. 607-615
Daniel O. Bennardi, Diego M. Ruiz, Gustavo P. Romanelli, Graciela T. Baronetti, Horacio J. Thomas and Juan C. Autino
[Abstract] [Full Text Article]


Eco-Friendly Accomplishment of the Extended Kabachnik–Fields Reaction; a Solvent- and Catalyst-Free Microwave-Assisted Synthesis of α-Aminophosphonates and α-Aminophosphine Oxides Pp. 616-622
György Keglevich and Anna Szekrényi
[Abstract] [Full Text Article]


A Mild and Efficient Synthesis of 3-Aminosubstituted Isothiazole S-Oxides and their 5-Sulfanylsubstituted Derivatives Pp. 623-627
Alessandro Casoni, Francesca Clerici, Alessandro Contini, Sara Pellegrino and Alessandro Sala
[Abstract] [Full Text Article]


Imino Diels-Alder Reactions: Efficient Synthesis of Pyrano and Furanoquinolines Catalyzed by Antimony (III) Sulfate Pp. 628-632
Mahesh A. Goudar, Honnali Jayadevappa, Aralihalli Sudhakara and Kittappa M. Mahadevan
[Abstract] [Full Text Article]


Synthesis and Evaluation of Phytotoxicity of Disugran Analogues Pp. 633-639
Silvana M. Basso, Juan P. Montañez and Ana N. Santiago
[Abstract] [Full Text Article]


Synthesis of Steroidal Mimics of Estrogens Using Wittig and McMurry Reactions Pp. 640-643
Atul Gupta and Suprabhat Ray
[Abstract] [Full Text Article]


Synthesis and Anti-HSV-1 In Vitro Activity of New Phosphoramidates with 4-oxoquinoline and Phtalimidic Nuclei Pp. 644-650
Thiago S. Torres, William P. de Macedo, Leandro F. Pedrosa, Maria Cecília B. V. de Souza, Vítor F. Ferreira, Anna Cláudia Cunha, Tamara Fogel, Fernanda da C. Santos, Isakelly P. Marques, Izabel Cristina de P. Paixão and Marcos C. de Souza
[Abstract] [Full Text Article]


The Hydroamination of Unactivated Alkenes with Sulfonamides Catalyzed by Phosphomolybdic Acid/SiO₂ Pp. 651-654
Jhillu S. Yadav, Basi V.S. Reddy, Ande Raju, Kontham Ravindar and Ravirala Narender
[Abstract] [Full Text Article]


A Recyclable Catalyst for the Synthesis of 1,5-Benzodiazepine Derivatives:Polymer-Supported Ytterbium Perfluorooctanesulfonate [Yb(OPf)₃] Pp. 655-658
Feng Tao and Wen-Bin Yi
[Abstract] [Full Text Article]


Metal Free One Pot Approach Towards the Synthesis of Hantzsch Esters and their Application as the Hydrogen Source for the Reduction of Activated Olefins Catalysed by Bromo Dimethyl Sulfonium Bromide (BDMS) Pp. 659-664
Papori Goswami, Shahzad Ali, Md. M. Khan and Babulal Das
[Abstract] [Full Text Article]


Highly Selective Catalytic Friedel–Crafts Acylation of Activated Aromatic Compounds Using the I₂.DMF Complex as Catalyst Pp. 665-668
Faouzi Guenadil, Hocine Aichaoui, Didier M. Lambert, Christopher R. McCurdy and Jacques H. Poupaert
[Abstract] [Full Text Article]


One-Pot Rapid and Efficient Synthesis of Gem-Bisallylated Alcohols Mediated by Zinc-Copper Couple under Solvent-free Conditions Pp. 669-671
Heng Ren, Yujuan Wei and Jin-Xian Wang
[Abstract] [Full Text Article]


The Deracemization of Secondary Alcohols via a Chemo-Enzymatic Process Pp. 672-675
Xiaomei Wu, Jiaying Xin, Limin Zhu, Chris Branford-white, Wei Sun, Jianhe Xu and Chungu Xia
[Abstract] [Full Text Article]


Recognition of Anions Using p-Nitrophenyl Thiourea Based on 1,1’- Binaphthyl-2,2’-diol Pp. 676-683
Youhei Takahashi, Tatsunori Sato and Kazuaki Ito
[Abstract] [Full Text Article]


Generation of Nano C₆H₁₂O₆ from Graphite through Arc Discharge: A Clue for the Origin of Life Pp. 684-686
Mohammad Z. Kassaee, Monireh Ghavami, Mohaddeseh Majdi and Ameneh C. Kani
[Abstract] [Full Text Article]


Modification of Taxane A Ring via Manoeuvering of the C-11 Double Bond of 10-Deacetylbaccatin III to Get Novel Rearranged Taxoids Pp. 687-691
Vaishali Chakraborty and Manobjyoti Bordoloi
[Abstract] [Full Text Article]


The Effect of Phenyl Substituents on ¹³C NMR Shifts and Metal Ions Binding to 4-Phenyl-2,4-Dioxobutanoic Acid Derivatives Pp. 692-699
Tatjana Ž. Verbic, Branko J. Drakulic, Mire Zloh and Ivan O. Juranic
[Abstract] [Full Text Article]




Abstracts



[Back to top] [Full Text Article]
Enantioselective Michael Addition of Dimethyl Malonate to (E)-β- Nitrostyrenes Catalyzed by Cinchona Alkaloids Under Solvent- Free Condition
Francesco Fringuelli, Luca Castrica, Ferdinando Pizzo and Luigi Vaccaro

Under solvent-free condition the addition of dimethyl malonate (1) to (E)-β-nitrostyrenes 2a-j proceeds smoothly in the presence of 2.5 mol% of 6’-hydroxy cinchonine (QD-OH) and equimolar amounts of reagents at 30°C. The corresponding products 3a-j are obtained with satisfactory enantiomeric excesses (68-88%) and high yields (70-92%).


[Back to top] [Full Text Article]
Efficient Microwave Solvent-Free Synthesis of Flavones, Chromones, Coumarins and Dihydrocoumarins
Daniel O. Bennardi, Diego M. Ruiz, Gustavo P. Romanelli, Graciela T. Baronetti, Horacio J. Thomas and Juan C. Autino

Simple, clean, environmentally friendly procedures for the solvent-free preparation of coumarins, dihydrocoumarins, flavones and chromones under microwave heating are described. Silica-supported Wells-Dawson heteropolyacid (H₆P₂W₁₈O₆₂·24 H₂O) was employed as catalyst. High selectivity, very good yields and short reaction times were obtained. The results are compared with those of the reactions performed under conventional heating.


[Back to top] [Full Text Article]
Eco-Friendly Accomplishment of the Extended Kabachnik–Fields Reaction; a Solvent- and Catalyst-Free Microwave-Assisted Synthesis of α-Aminophosphonates and α-Aminophosphine Oxides
György Keglevich and Anna Szekrényi

The Kabachnik–Fields reaction may be carried out under a variety of conditions. More recently, the application of ”exotic” catalysts, in most cases in traditional solvents and a few instances in ionic liquids, came into fashion. Using a pool of simple model compounds, still extending the scope of the reaction under discussion, it is shown that the simplest, most straightforward and most environmentally friendly accomplishment of the condensation of the oxo-component, the amine and the >P(O)H species to afford α-aminophosphonates or phosphine oxides involves microwave irradiation of the neat reaction mixture without the use of any catalyst. In some cases, the reaction is more clear-cut if the title compounds are prepared by a two-step one-pot procedure.


[Back to top] [Full Text Article]
A Mild and Efficient Synthesis of 3-Aminosubstituted Isothiazole S-Oxides and their 5-Sulfanylsubstituted Derivatives
Alessandro Casoni, Francesca Clerici, Alessandro Contini, Sara Pellegrino and Alessandro Sala

The present paper describes a mild and efficient method to synthesize 3-aminosubstituted isothiazole sulfoxides taking advantage of arylsulfonyloxaziridines. The reactivity of the resulting isothiazole sulfoxides toward sulfur nucleophiles has been studied and resulted in the formation of 5-sulfanylsubstituted isothiazoles in a fully diastereoselective way. From 3-benzylamino-5-chloro isothiazole S-oxide an addition-elimination reaction took place affording smoothly the corresponding unsaturated 5-sulfanyl derivatives.


[Back to top] [Full Text Article]
Imino Diels-Alder Reactions: Efficient Synthesis of Pyrano and Furanoquinolines Catalyzed by Antimony (III) Sulfate
Mahesh A. Goudar, Honnali Jayadevappa, Aralihalli Sudhakara and Kittappa M. Mahadevan

The Imino Diels-Alder reaction of N-benzylideneanilines with 3, 4-dihydro-2H-pyran and 2, 3-dihydrofuran proceeds smoothly to afford pyrano and furanoquinolines 3a-i and 4a-i in the presence of Antimony (III) Sulfate as catalyst. A concise and efficient synthetic route has been developed for one pot synthesis of pyrano and furano quinolines 6a-l and 7a-l by the reaction between anilines and 3, 4-dihydro-2H- pyran and 2, 3-dihydrofuran respectively in fairly good yields. This catalyst is inexpensive, easily available and it was also found that catalyst could be recovered quantitatively and reused without much loss of catalytic activity.


[Back to top] [Full Text Article]
Synthesis and Evaluation of Phytotoxicity of Disugran Analogues
Silvana M. Basso, Juan P. Montañez and Ana N. Santiago

We report the synthesis and phytotoxicity of the compounds involved in the S_RN1-Stille reactions such as methyl 2,5-diphenylbenzoate (6), methyl 5-chloro-2-phenylbenzoate (7) and methyl 2-methoxy-3,6-diphenylbenzoate (8) as well as the phytotoxicity of intermediates. 8 has a good herbicide activity compared to Disugran and it isn’t a chlorinated compound.


[Back to top] [Full Text Article]
Synthesis of Steroidal Mimics of Estrogens Using Wittig and McMurry Reactions
Atul Gupta and Suprabhat Ray

Syntheses of diene based steroidal mimics of the estrogens, 2 and 3, were made through Wittig and McMurry reactions, as templates for estrogen receptor modulators.


[Back to top] [Full Text Article]
Synthesis and Anti-HSV-1 In Vitro Activity of New Phosphoramidates with 4-oxoquinoline and Phtalimidic Nuclei
Thiago S. Torres, William P. de Macedo, Leandro F. Pedrosa, Maria Cecília B. V. de Souza, Vítor F. Ferreira, Anna Cláudia Cunha, Tamara Fogel, Fernanda da C. Santos, Isakelly P. Marques, Izabel Cristina de P. Paixão and Marcos C. de Souza

Aminoalkyl phosphoramidates were obtained by either direct phosphorylation of symmetric diamines or a three steps method analogue to Gabriel’s synthesis and coupled to a 4-oxoquinoline acyclonucleoside, in order to synthesize 4-oxoquinolone phosphoramidates. Two unpublished compounds demonstrated low cytotoxity in comparison to Acyclovir and good HSV-1 cytophatic effects on Acyclovir resistant strains.


[Back to top] [Full Text Article]
The Hydroamination of Unactivated Alkenes with Sulfonamides Catalyzed by Phosphomolybdic Acid/SiO₂
Jhillu S. Yadav, Basi V.S. Reddy, Ande Raju, Kontham Ravindar and Ravirala Narender

Phosphomolybdic acid (PMA) supported on silica gel (SiO₂) is found to catalyze efficiently the hydroamination of unactivated alkenes with sulfonamides to produce tosyl and mesyl protected secondary amines in excellent yields in short reaction times. The use of reusable solid acid catalyst, phosphomolybdic acid/SiO₂ makes this method quite simple, more convenient, cost-effective and environmentally friendly.


[Back to top] [Full Text Article]
A Recyclable Catalyst for the Synthesis of 1,5-Benzodiazepine Derivatives: Polymer-Supported Ytterbium Perfluorooctanesulfonate [Yb(OPf)₃]
Feng Tao and Wen-Bin Yi

Amberlyst-21, a kind of well-known and cheap polymeric material, was treated with ytterbium perfluorooctanesulfonate [Yb(OPf)₃] giving a reagent with a ytterbium loading of 1.34 (wt %). The polymer-supported fluorous ytterbium catalyses the highly efficient synthesis of 1,5-benzodiazepine derivatives. The catalyst can be recovered by simple filtration under fluorous-solvent-free conditions and used again without a significant loss of catalytic activity.


[Back to top] [Full Text Article]
Metal Free One Pot Approach Towards the Synthesis of Hantzsch Esters and their Application as the Hydrogen Source for the Reduction of Activated Olefins Catalysed by Bromo Dimethyl Sulfonium Bromide (BDMS)
Papori Goswami, Shahzad Ali, Md. M. Khan and Babulal Das

An environmentally benign one pot synthesis of dihydropyridines and its use as hydrogen source in the reduction of α,β-unsaturated aldehydes and ketones using catalytic amount of BDMS at room temperature is described. An extensive study on the role of substituents on aldehyde for the formation of Hantzsch esters, reveals that presence of more than one electron donating substituents, hinders the formation of dihydropyridine derivative.


[Back to top] [Full Text Article]
Highly Selective Catalytic Friedel–Crafts Acylation of Activated Aromatic Compounds Using the I₂.DMF Complex as Catalyst
Faouzi Guenadil, Hocine Aichaoui, Didier M. Lambert, Christopher R. McCurdy and Jacques H. Poupaert

A novel method has been developped for synthesizing aryl ketones by means of I₂-DMF mediated Friedel–Crafts acylation of aromatic substrates. The reaction is applicable to activated aromatic compounds. The present process is carried out under conditions involving minimal wastes and energy-consumption as compared to the use of molecular iodine.


[Back to top] [Full Text Article]
One-Pot Rapid and Efficient Synthesis of Gem-Bisallylated Alcohols Mediated by Zinc-Copper Couple under Solvent-free Conditions
Heng Ren, Yujuan Wei and Jin-Xian Wang

An efficient and rapid procedure for the conversion of various carboxylic acid derivatives into the corresponding gem-bisallylated compounds under mild reaction conditions has been developed. Zinc-copper couple mediating Barbier-type addition of carboxylic acid derivative was utilized as a key operation to affect the transformation. The procedure is operationally simple, giving good to high product yield.


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The Deracemization of Secondary Alcohols via a Chemo- Enzymatic Process
Xiaomei Wu, Jiaying Xin, Limin Zhu, Chris Branford-white, Wei Sun, Jianhe Xu and Chungu Xia

Optically pure secondary alcohols were efficiently prepared via a two-step, one-pot process involving a chemical oxidative agent in combination with an enantioselective ketone reducase Rhodotorula sp. AS2.2241 in tandem. The reaction proceeded successfully with 88~99.5% enantiomeric excess in moderate to good conversions. A variety of substrates, including aromatic and aliphatic alcohols, could be tolerated.


[Back to top] [Full Text Article]
Recognition of Anions Using p-Nitrophenyl Thiourea Based on 1,1’- Binaphthyl-2,2’-diol
Youhei Takahashi, Tatsunori Sato and Kazuaki Ito

The di-thioureas (1) and mono-thioureas (3) based on 1,1’-binaphthyl-2,2’-diol exhibited a preference for Cl- with a 1:1 stoichiometry. The cooperativity of the two binding sites (two thiourea groups for 1, thiourea and hydroxyl groups for 3) for anion binding was established by comparing the binding of the mono-thiourea receptors (2) based on naphthyl.


[Back to top] [Full Text Article]
Generation of Nano C₆H₁₂O₆ from Graphite through Arc Discharge: A Clue for the Origin of Life
Mohammad Z. Kassaee, Monireh Ghavami, Mohaddeseh Majdi and Ameneh C. Kani

The SEM and XRD data show an unprecedented arc fabrication of spherical monoclinic crystals of nano dihydroxyacetone dimer (C₆H₁₂O₆) from graphite, with a grape cluster morphology, in the size range of 40 to 150 nm, in the open air, providing another clue for the proposed arc discharge origin of organics and/or life.


[Back to top] [Full Text Article]
Modification of Taxane A Ring via Manoeuvering of the C-11 Double Bond of 10-Deacetylbaccatin III to Get Novel Rearranged Taxoids
Vaishali Chakraborty and Manobjyoti Bordoloi

Modification of A ring of 10-deacetylbaccatin III to get novel rearranged taxoids is described. The modification is achieved via manoeuvering of the C-11 double bond of 10-deacetylbaccatin III.


[Back to top] [Full Text Article]
The Effect of Phenyl Substituents on ¹³C NMR Shifts and Metal Ions Binding to 4-Phenyl-2,4-Dioxobutanoic Acid Derivatives
Tatjana Ž. Verbic, Branko J. Drakulic, Mire Zloh and Ivan O. Juranic

Butanoic moiety of 4-aryl-2,4-dioxobutanoic acids is involved in interactions with metal ions within HIV-1 integrase active site. Sixteen congeneric 4-phenyl-2,4-dioxobutanoic acid derivatives with different substitution on the phenyl ring were prepared. Effects of substitution were studied by spectrometric methods (NMR, MS, UV/VIS) and linear free energy relationships. Better metal complexation ability of meta-alkyl substituted compounds, was observed. This observation might have pharmacological implications.