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Letters in Organic Chemistry
ISSN: 1570-1786
Letters in Organic Chemistry
Volume 7, Number 5, July 2010
Contents
Graphical
Abstracts Pp. i-v
Fast [3+2] Cycloaddition Synthesis of (±) Pterocarpans under Microwave Irradiation Pp. 348-352
Claiton P. Ventura, Iara Maíra de O. Viana, Erúzia A.E. Ferreira,
Rossimiriam P. de Freitas and Rosemeire B. Alves
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Synthesis of the Azetidinyl-Thiazoline Fragment of Vioprolides
A and C Pp. 353-359
Nathalie Chopin, François Couty and Gwilherm Evano
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Article]
Synthesis and In-Vitro Antitumor Activity of Selected 7-Fluoro-6-(4-methyl-1-piperazinyl)-2-(thiosubstituted)-4(3H)-quinazolinones Pp. 360-366
Raid J. Abdel-Jalil, Ehab Al-Momani, Lubna Tahtamooni, H.-Juergen Machulla and Wolfgang Voelter
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Editor’s
Choice
Asymmetric Michael Addition of Aromatic Ketones to Nitroolefins
Catalyzed by Simple Chiral Bifunctional Primary Amine-Thioureas Pp. 367-372
Liangliang Wang, Xiaoying Xu, Jun Huang, Lin Peng, Qingchun Huang and Lixin Wang
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Isoprene-Mediated Lithiation of 1-Alkylimidazoles: Chiral Induction
of the Alkyl Substituent Pp. 373-376
Isidro M. Pastor, Rosario Torregrosa and Miguel Yus
[Abstract] [Purchase
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Reaction of 3,4-Dihydro-β-Carbolines with 4-Fluorophenyl-Nitrile
Oxide Pp. 377-382
Mátyás Milen, Péter Ábrányi-Balogh, András Dancsó, Gyula Simig and György Keglevich
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4-Thio Derivatives of Dibenzosuberone: Potential Antidepressant Compounds Pp. 383-387
Paulo R.C. Martins, Gilberto A. Romeiro and Carlos M.R. Ribeiro
[Abstract] [Purchase
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Convenient Direct Reductive Amination of Carbonyl Compounds in a Completely Aqueous Media Pp. 388-391
Cristian Simion, Alina M. Simion, Takashi Arimura, Akira Miyazawa and Masashi Tashiro
[Abstract] [Purchase
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A Simple and Efficient Thiocyanation of Indoles, Anilines and Keto
Compounds Catalyzed by a Polystyrene Resin Amberlyst-15 Pp. 392-395
Racha Lenin and Rallabandi M. Raju
[Abstract] [Purchase
Article]
Efficient Synthesis of Wang Resin-Supported 6-O-Benzylallosamizoline Pp. 396-398
Gangliang Huang and Qin Yang
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Article]
Recognition of Anions by bis Urea based Fluorescent Receptors Pp. 399-405
Shyamaprosad Goswami and Subrata Jana
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Article]
One-Pot Four Component Synthesis of 4, 6-Disubstituted
3-Cyano-2-Pyridones in Polyethylene Glycol Pp. 406-410
Santosh V. Nalage, Ajay P. Nikum, Mohan B. Kalyankar, Vijay S. Patil,
Umesh D. Patil, Kamlesh R. Desale, Shamkant L. Patil and Sidhanath V. Bhosale
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Article]
A New Method of Reducing 2-Mercapto-Substituted 1,3,4-Oxadizoles: Synthesis of Acylhydrazine Derivatives Pp. 411-414
Muhammad Zareef, Rashid Iqbal, Javid Hussain Zaidi, Muhammad Arfan,
Muhammad Ali and Khalid M. Khan
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Article]
An Improved Method for the Synthesis of Disulfides by Periodic
Acid and Sodium Hydrogen Sulfite in Water Pp. 415-419
Khalid M. Khan, Muhammad Taha, Fazal Rahim, Muhammad Ali, Waqas Jamil,
Shahnaz Perveen and M. Iqbal Choudhary
[Abstract] [Purchase
Article]
Abstracts
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Fast [3+2] Cycloaddition Synthesis of (±) Pterocarpans under Microwave Irradiation
Claiton P. Ventura, Iara Maíra de O. Viana, Erúzia A.E. Ferreira,
Rossimiriam P. de Freitas and Rosemeire B. Alves
Herein we describe a method for the fast cycloaddition reaction of 2H-chromenes with 2-methoxy-1,4-benzoquinones by microwave heating. Using this methodology we have synthesised seven pterocarpans derivatives, five of which are novel compounds. Microwave heating allows significant yield enhancements and reduction of reaction time when compared to traditional methodology.
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Synthesis of the Azetidinyl-Thiazoline Fragment of Vioprolides
A and C
Nathalie Chopin, François Couty and Gwilherm Evano
An efficient synthesis of the azetidinyl-thiazoline fragment of the antifungal and cytotoxic macrolides vioprolides A and Cis reported. Key steps of the synthesis include formation of the thiazoline by condensation of N-Alloc-trans (2S,4R)-4-methylazetidine-2-carbonitrile with L-cysteine and formation of the four-membered ring by intramolecular alkylation of a suitably protected N-Alloc derivative prepared from (R)-alaninol.
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Synthesis and In-Vitro Antitumor Activity of Selected 7-Fluoro-6-(4-methyl-1-piperazinyl)-2-(thiosubstituted)-4(3H)-quinazolinones
Raid J. Abdel-Jalil, Ehab Al-Momani, Lubna Tahtamooni, H.-Juergen Machulla and Wolfgang Voelter
A new series of 7-fluoro-6-(4-methyl-1-piperazinyl)-2-(thiosubstituted)-4(3H)-quinazolinones was synthesized as potential antitumor agents by multi-step synthesis starting with the commercially available 3-chloro-4-fluoroaniline. The most promising candidate, 7-fluoro-6-(4- methyl-1-thyl-1-piperazinyl)- 2-thioethyl-4(3H)-quinazolinone (5a), was screened in 60 human cancer cells by NCI.
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Asymmetric Michael Addition of Aromatic Ketones to Nitroolefins
Catalyzed by Simple Chiral Bifunctional Primary Amine-Thioureas
Liangliang Wang, Xiaoying Xu, Jun Huang, Lin Peng, Qingchun Huang and Lixin Wang
Simple chiral primary amine-thiourea catalysts derived from chiral 1,2-diphenylethylenediamine were found to catalyze direct Michael addition of aromatic ketones to nitroolefins with good enantioselectives (up to 86% ee) and excellent yields (up to 97%) for a broad range of substrates and successfully used in the preparation of (R)-Balcofen.
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Isoprene-Mediated Lithiation of 1-Alkylimidazoles: Chiral Induction
of the Alkyl Substituent
Isidro M. Pastor, Rosario Torregrosa and Miguel Yus
The isoprene-mediated lithiation of imidazoles bearing a secondary alkyl substituent at the nitrogen (7, 8 and 13) and the subsequent nucleophilic addition to different electrophiles allows the preparation of the corresponding 2-functionalized imidazoles 10, 11 and 14. The presence of a stereogenic center in the alkyl substituent induces diastereoselection during the nucleophilic addition step with a prochiral electrophile (i.e. pivalaldehyde), producing the expected imidazole derivative with excellent overall yield, but low de (up to 26%).
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Reaction of 3,4-Dihydro-β-Carbolines with 4-Fluorophenyl-Nitrile
Oxide
Mátyás Milen, Péter Ábrányi-Balogh, András Dancsó, Gyula Simig and György Keglevich
The reaction of 3,4-dihydro-β-carboline 5a with the nitrile oxide generated from 4-fluoro-N-hydroxybenzenecarboximidoyl chloride (6) gave novel adduct 7a that on standing at 26 °C in CDCl3 was isomerized to species 8. As an extension, the reaction of the dihydro-β-carbolines substituted on C(1) (5b-e) afforded the analogous adducts (7b-e). In case of using two equivalents of reagent 6, the corresponding 1,2,4-triazole-2-oxide (10b-e) was also formed beside the adduct (7b-e).
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4-Thio Derivatives of Dibenzosuberone: Potential Antidepressant Compounds
Paulo R.C. Martins, Gilberto A. Romeiro and Carlos M.R. Ribeiro
This work describes the synthesis of a series of nine 4-thio dibenzosuberone derivatives (10,11-dihydro-5H-dibenzo[a,d]cycloheptane-5-one derivatives). Ullmann´s reaction was used to synthesize six 4-thio dibenzosuberone derivatives 10-15 from 4-iodo dibenzosuberone 9. Compound 9 was synthesized from dibenzosuberone 7 through the use of TTFA [thallium (III) trifluoroacetate] and KI. Hydrolysis of 10 yielded derivative 14. Compound 17, which was prepared through the chlorination of 14, was aminated to furnish 4-thio derivative 18.
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Convenient Direct Reductive Amination of Carbonyl Compounds in a Completely Aqueous Media
Cristian Simion, Alina M. Simion, Takashi Arimura, Akira Miyazawa and Masashi Tashiro
We report hereby a particularly efficient synthesis of secondary, and tertiary amines respectively, through a direct reductive amination process carried for the first time in a completely aqueous media.
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Article]
A Simple and Efficient Thiocyanation of Indoles, Anilines and Keto
Compounds Catalyzed by a Polystyrene Resin Amberlyst-15
Racha Lenin and Rallabandi M. Raju
Thiocyanation of various aromatic, heteroaromatic and enolizable ketone compounds has been achieved with ammonium thiocyanate in presence of polystyrene cation exchange resin, Amberlyst-15. All the reactions were carried out in acetonitrile at room temperature.
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Efficient Synthesis of Wang Resin-Supported 6-O-Benzylallosamizoline
Gangliang Huang and Qin Yang
An efficient procedure of flash heating by microwave irradiation was described for the attachment of 6-O-benzylallosamizoline 8 to chloromethylated Wang resin 7 via its corresponding stannylene intermediate. The reaction rate and loading for compound 8 were significantly enhanced when the microwave irradiation protocol was compared with the conventional heating method.
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Recognition of Anions by bis Urea based Fluorescent Receptors
Shyamaprosad Goswami and Subrata Jana
Three bis urea based acyclic receptors with fixed spacer and varying size of substituents have been synthesized and their binding behavior with different anions are reported along with the selectivity of these receptors towards anions. The fluorescence quenching of the receptors 2 and 3 on binding with anions is also shown. The receptor 1 binds better with Y-shaped AcO- ion whereas receptor 3 binds well with Cl- ion.
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One-Pot Four Component Synthesis of 4, 6-Disubstituted
3-Cyano-2-Pyridones in Polyethylene Glycol
Santosh V. Nalage, Ajay P. Nikum, Mohan B. Kalyankar, Vijay S. Patil,
Umesh D. Patil, Kamlesh R. Desale, Shamkant L. Patil and Sidhanath V. Bhosale
The reaction of ketone, aldehyde, ethyl cyanoacetate and ammonium acetate in polyethylene glycol-600 is reported. The reaction proceeds smoothly in the absence of catalyst to yield 2-Pyridones.
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A New Method of Reducing 2-Mercapto-Substituted 1,3,4-Oxadizoles: Synthesis of Acylhydrazine Derivatives
Muhammad Zareef, Rashid Iqbal, Javid Hussain Zaidi, Muhammad Arfan,
Muhammad Ali and Khalid M. Khan
A new method has been developed for the synthesis of acylhydrazines 5a-g by the reduction of unsymmetrical 1,3,4-oxadiazoles 4a-g by using sodium borohydride/acetic acid combination. Later on, acylhydrazines 5a-g were converted to their corresponding sulfonamide derivatives 6a-d.
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An Improved Method for the Synthesis of Disulfides by Periodic
Acid and Sodium Hydrogen Sulfite in Water
Khalid M. Khan, Muhammad Taha, Fazal Rahim, Muhammad Ali, Waqas Jamil,
Shahnaz Perveen and M. Iqbal Choudhary
An improved method for the synthesis of disulfide in water by using periodic acid and sodium hydrogen sulfite was developed.
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