Letters in Organic Chemistry

ISSN: 1570-1786

Letters in Organic Chemistry
Volume 3, Number 4, April 2006

Highlights in Organic Chemistry

The Photo SN1 Reaction Via Phenyl Cation Pp. 253-259

Maurizio Fagnoni A survey on phenyl SN1 reactions forming new Ar-C bonds accomplished by the reaction of photogenerated phenyl cations (by heterolytic cleavage of phenyl halides and esters) with various nucleophiles (olefins, (hetero)arenes, alkynes).

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Letters in Organic Chemistry

Anion Receptors Based on Acyclic Phenol-Formaldehyde Oligomers Bearing Thiourea Groups Pp. 260-266

Kazuaki Ito, Takeshi Ito, Toshiro Takasawa & Yoshihiro Ohba Acyclic phenol-formaldehyde oligomers (1b and 1c) bearing thiourea groups showed the binding selectivity toward chloride and hydrogen sulfate, respectively.

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Silphos [PCl3-n(SiO2)n], a Heterogeneous Phosphine Reagent Mediated the Conversion of Oximes to Nitriles and Amides or Carbonyl Compounds Pp. 267-270

Nasser Iranpoor, Habib Firouzabadi, Arezu Jamalian & Mana Tamami Silphos provides a method for the dehydration of aldoximes, Beckmann rearrangement of ketoximes, and also deprotection of oximes in high yield and purity. The separation of the produced Silphos oxide is chromatography-free and simply by filtration.

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Mild, Efficient and Highly Selective Hydrolysis of Acetonides with Antimony Trichloride Pp. 271-274

Qinpei Wu, Wei Chen, Yuan Wang, Yunbo Qu & Qingshan Zhang A mild and efficient procedure for hydrolysis of acetonide with SbCl3 in the presence of other frequently used hydroxy protecting groups was chemoselective and regioselective. The mechanism was examined and suggested.

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Cyanosilylation of Hetero-Substituted Ketones Catalyzed by LiCl Pp. 275-277

Nobuhito Kurono, Ken Suzuki & Takeshi Ohkuma LiCl efficiently catalyzes cyanosilylation of various hetero-substituted ketones. α,α-Dialkoxy ketones are completely converted to silylated cyanohydrins with a substrate-to-catalyst molar ratio of 100,000.

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Pinacol Coupling of Aromatic Aldehydes Using TiCl3-Al-H2O Under Ultrasound Irradiation Pp. 278-281

Zhi-Ping Lin, Ji-Tai Li & Tong-Shuang Li Al can reduce titanium trichloride in water to the corresponding low valent titanium complexes, which can reduce some aromatic aldehydes to the corresponding pinacols in 35-83 % yields within 25-100 min at r.t. under ultrasound irradiation.

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A Silica-Supported Copper(I) Catalyzed Sonogashira Coupling Reaction Pp. 282-285

Liyuan Zhang, Pinhua Li & Lei Wang A highly active 3-(2-aminoethylamino)propyl functionalised silica gel immobilised copper(I) catalyst was prepared, which was used as an effective catalyst for the Sonogashira coupling reaction of terminal alkynes with aryl iodide and aryl bromide in the presence of triphenylphosphine, potassium carbonate in DMF..

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Synthesis of 5-Substituted-1,3,4-Oxadiazole-2(3H)-Thiones Under Microwave Irradiation Pp. 286-288

Khalid Mohammed Khan, Sohail Anjum Shahzad, Mubeen Rani, Muhammad Ali, Shahnaz Perveen, Awais Anwar & Wolfgang Voelter A variety of 5-substituted-1,3,4-oxadiazole-2(3H)-thiones were synthesized using microwave irradiation under solvent free conditions. The reaction time was reduced from 5-14 h to 3-7 min affording high yields from corresponding acyl and aroyl hydrazides.

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Efficient Solvent-Free Synthesis of Quinolines Promoted by BiCl3 Pp. 289-291

Cheng-Sheng Jia & Guan-Wu Wang A straightforward and efficient protocol for the solvent-free synthesis of quinolines via BiCl3-promoted Friedlander reaction of o-aminoarylketone or o-aminoarylaldehyde with α-methylene ketones was developed.

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KBrO3 in the Presence of Fe(HSO4)3/Wet SiO2: Efficient Oxidation of Alcohols and Trimethylsilyl and Tetrahydropyranyl Ethers Pp. 292-296

Farhad Shirini, Mohammad Ali Zolfigol & Abdol-Reza Abri Alcohols and trimethyl and tetrahydropyranyl ethers were efficiently converted to their corresponding carbonyl compounds with KBrO3 in the presence of Fe(HSO4)3 and wet SiO2 in solution and under solvent-free conditions.

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“On Water”: Rapid Knoevenagel Condensation Using Sodium Pyruvate Pp. 297-299

Majid M. Heravi, Fatemeh Derikvand, Masoumeh Haghighi & Khadijeh Bakhtiari A high yielding and fast method of Knoevenagel condensation of malonitrile and ethylcyanoacetate with various aldehydes using sodium pyruvate in aqueous media is described.

A Straightforward Synthetic Approach to Antitumoral Pyridinyl Substituted 7H-Indeno[2,1-c]Quinoline Derivatives Via Three-Component Imino Diels-Alder Reaction Pp. 300-304

Vladimir V. Kouznetsov, Cristian Ochoa Puentes, Arnold R. Romero Bohórquez, Susana A. Zacchino, Maximiliano Sortino, Mahabir Gupta, Yelkaira Vázquez, Ali Bahsas & Juan Amaro-Luis A simple and efficient synthetic method of obtaining pyridinyl substituted indeno[2,1-c]quinoline derivatives has been developed. Most compounds of these series were devoid of antifungal properties against a panel of standard dermatophytes, however nearly all of them were active against breast (MCF-7), lung (H-460) and central nervous system (SF-268) human cancer cell lines.

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SiO2/N2O4 and Fe(NO3)3.9H2O/H3PMo12O40.xH2O Systems as Powerful Oxidants for Removal of Cyclic Dioxalanes and Dithianes Pp. 305-308

Mohammad Ali Zolfigol, Iraj Mohammadpoor-Baltork, Ardeshir Khazae, Morteza Shiri & Zahra Tanbakouchian SiO2/N2O4 system was used as an efficient oxidant for the conversion of cyclic dioxalanes and dithianes to parent carbonyl compound in CH2Cl2 at room temperature. We also found Fe(NO3)3.9H2O/H3PMo12O40.xH2O could be used as a powerful oxidation complex for similar transformations at room temperature under solvent free conditions.

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One-Pot Synthesis of β-Hydroxy-1,3-Dienes Via Allyltriphenylphosphonium Isomerization Under Mild Conditions Pp. 309-312

Diver Sellanes, Laura Scarone, Eduardo Manta, Peter Wipf & Gloria Serra Reaction of allyltriphenylphosphonium bromide and Garner's aldehyde in basic media provided β-hydroxy-1,3-dienes. Similar results are described for other aliphatic and aromatic aldehydes.

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A One-Pot Synthesis of D-Ribonucleosides Using Natural Phosphate Doped with KI in HMDS Pp. 313-314

Hassan Bihi Lazrek, Driss Ouzebla, Abdellali Rochdi, Nezha Redwane & Jean-Jacques Vasseur KI supported on natural phosphate was used as a promotor in synthesis of several D-ribonucleosides.

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A Radical Route to a cis-3,5-Dialkyl Proline Derivative Pp. 315-316

Sébastien Guesné, Sébastien Comesse & Catherine Kadouri-Puchot β Amino alcohols 5 possessing an alkynyl functionality were converted into bicyclic compounds 8 via a 5-exo-dig radical cyclization. One of this bicyclic product was transformed in three steps into the (2R,3S,5S)-3-methyl-5-iso-propyl proline.

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Synthesis of Polyhydroquinoline Derivatives Under Solvent-Free Conditions Pp. 317-319

Wei-Yi Chen, Jun Lu & Jian-Rong Jin A series of 1,4- dihydropyridines derivatives have been obtained by the reaction of chalcones with dimedone in the presence of ammonium formate under solvent-free conditions. Each title compound was formed in good yield.

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Microwave-Assisted Amination of Aryltrifluoroborates Pp. 320-323

George W. Kabalka & Li-Li Zhou A microwave-assisted amination reaction involving aryltrifluoroborates has been developed. This solvent-free coupling reaction is noteworthy for its experimental simplicity.

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Aza-Michael Additions on α,β-Unsaturated Esters Catalysed by Bismuth (III) Triflate in Conventional Chemistry and Under Microwave Irradiation Pp. 324-327

Jérémy Monfray & Ari M.P. Koskinen Aza-Michael additions were investigated in the presence of catalytic amounts of bismuth (III) triflate under conventional and microwave irradiation conditions. Combination of both the catalyst and microwave irradiation under solvent-free conditions enhances the conjugate addition of amines to α,β-unsaturated esters.

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