Letters in Organic Chemistry

ISSN: 1570-1786

Letters in Organic Chemistry
Volume 3, Number 5, May 2006

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Highlights in Organic Chemistry

Catalytic Asymmetric Acyl-transfer Mediated by Chiral Pyridine Derivatives Pp. 333-338

Stephen J. Connon A highlight article outlining recent advances in the development of chiral pyridine-based asymmetric acyl-transfer organocatalysts for the kinetic resolution of sec-alcohols and a range of other synthetically useful transformations.

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Recent Advances in Organocopper Chemistry Pp. 339-349

Vittorio Caprio The most recent advances in organocopper chemistry are reviewed. Recent developments in the preparation and application of these reagents in organic synthesis are discussed.

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Letters in Organic Chemistry

Diastereoselective Paternò-Büchi Reaction on Furan Derivatives–Reaction with Asymmetric Ketones Pp. 350-355

Maurizio D’Auria, Lucia Emanuele, Vita Pace & Rocco Racioppi The photochemical reaction of 2-phenylpropiophenone with furan and 2-methylfuran gave the corresponding Paternò-Büchi adducts. All the products were obtained with >98% de. The diastereoselectivity was explained by considering the relative stability of the biradical intermediates.

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Thermal Degradation of Peptides and Formation of Acrylamide Pp. 356-357

Jürgen Buhlert, Reinhold Carle, Zsuzsa Majer & Dietrich Spitzner Acrylamide and cinnamic amide are formed from alanine and phenylalanine containing peptides at 200°C without the assistance of an additional carbonyl compound.

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Microwave-Assisted Regiospecific Synthesis of 2-Trifluoromethyl-7-Trihalomethylated Pyrazolo[1,5-a]Pyrimidines Pp. 358-362

Marcos A.P. Martins, Wilson Cunico, Elisandra Scapin, Daniel J. Emmerich, Gabriela F. Fiss, Fernanda A. Rosa, Helio G. Bonacorso, Nilo Zanatta & Alex F.C. Flores The reaction of 5-trifluoromethyl-3-aminopyrazole with 1,1,1-trihalo-4-alkoxy-3-alken-2-ones in the presence of microwave induced techniques and by conventional method furnished regiospecific halomethylated pyrazolo [1,5-a]pyrimidines.

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Chiral Di-Imidazolium Molecular Tweezers: Synthesis and Enantioselective Recognition for Amino Acid Derivatives Pp. 363-367

Kui Luo, He-yan Jiang, Jin-song You, Qin-xiang Xiang, Sheng-jin Guo, Jing-bo Lan & Ru-gang Xie Novel chiral di-imidazolium tweezers were synthesized from L-alanine and L-phenylalanine and exhibited excellent enantioselective recognition toward amino acid derivatives.

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Convergent Synthetic Studies Towards the Ribosyl-Diazepanone Core of the Liposidomycins Pp. 368-370

Yann Bourdreux, Bruno Drouillat & Christine Greck New types of ribosyl-diazepanone derivatives of nucleoside antibiotic liposidomycins, 12a and 12b, have been synthesized. The ribosyl 7-membered heterocycles were formed by reductive amination of the α-ribosylamino acid 9 derived from D-ribose and the amino aldehydes 10a or 10b followed by a peptidic coupling reaction.

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A Very Short and Efficient Palladium-Catalyzed Access to the 3,4-Dihydro-2H-1,4-Benzoxazine Structure Pp. 371-374

Norbert Dominczak, Paul Lhoste, Boguslaw Kryczka & Denis Sinou Palladium-catalyzed reaction of N-substituted-2-aminophenols with propargylic carbonates afforded the corresponding 3,4-dihydro-2-alkylidene- or 3-alkylidene-2H-benzo[b] [1,4]oxazines depending on the nitrogen substituent.

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An Efficient Synthesis of Bis(indolyl)methanes (BIAs) Catalyzed by A Recyclable Solid Superacid SO42-/TiO2 Under Solvent-Free Condition Pp. 374-378

Zeng Xiao-Fei & Ji Shun-Jun Green, mild and efficient electrophilic substitution reactions of indoles with various aldehydes were carried out using solid superacid SO42-/TiO2 as recyclable catalyst, and afforded the corresponding bis(indolyl)methanes in excellent yields.

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Practical Outcome of Azaphthalimide Reduction with Zn/AcOH at Various Temperatures Pp. 379-383

Vladislav Z. Parchinsky, Vladimir V. Koleda, Olga Ushakova, Tatiana D. Talismanova, Dmitry V. Kravchenko & Mikhail Krasavin The method described offers a practical alternative to hitherto reported sodium borohydride reduction of 4-azaphthalimides which suffers from poor selectivity and isolated yields. Reductive manipulation of 5-azaphthalimides was studied for the first time.

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Efficient Diastereoselective Titanium(IV) Reductive Amination of Ketones Pp. 384-389

Chanaz Salmi, Yves Letourneux & Jean Michel Brunel A series of different ketones and (R)-phenylethylamine were involved in a diastereoselective titanium(IV) reductive amination reaction leading to the expected amines in moderate to excellent yields and important diastereoselectivities up to 100%.

Synthesis of C1-C6 Fragment of Caribenolide I Pp. 390-395

Matar Seck, Blandine Seon-Meniel, Jean-Christophe Jullian, Xavier Franck, Reynald Hocquemiller & Bruno Figadère The C1-C6 fragment of caribenolide I was prepared from furan, as the key methyl ketone depicted above, with an excellent control of the stereogenic centres. A Shapiro reaction will allow its coupling reaction with the other part of the molecule.

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Efficient Synthesis of Various Secondary Amines Through a Titanium(IV)isopropoxide-Mediated Reductive Amination of Ketones Pp. 396-401

Chanaz Salmi, Yves Letourneux & Jean Michel Brunel An efficient method for the synthesis of various secondary amines through a titanium(IV)isopropoxide–mediated reductive amination reaction of ketones is reported in excellent yields up to 98%.

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Synthesis of C2’-β-Fluoro-Substituted Adenine Nucleosides Via Pivaloyl Derivatives of Adenosine and 3’-Deoxyadenosine Pp. 402-408

Grigorii G. Sivets, Elena N. Kalinichenko & Igor A. Mikhailopulo Syntheses of 9-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)-adenine (9) its 3’-deoxy derivative 16 with the DAST treatment of the corresponding pivaloates 7 and 14 are described. Stereochemistry of compounds 7 and 14 as well as fluorides 9 and 16 was studied by PSEUROT 6.3 program.

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Substituent Effects on [1,3]-Rearrangement of Alkynyl S,N-Acetals to 1-Amino-3-Sulfenylallenes and their Conversion to α,β-Unsaturated Ketones Pp. 409-413

Toshiaki Murai, Yuichiro Mutoh & Kozue Fukushima The reaction of thioiminium salts with lithium phenylacetylide exclusively gave S,N-acetals, whereas the reaction with lithium (trimethylsilyl)acetylide gave 1-amino-3-sulfenylallenes via [1,3]-rearrangement, the easiness of which was highly dependent on the substituents at the nitrogen atom. Chromatographic purification of the reaction mixture produced α,,β-unsaturated ketones.

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PdCl2 Immobilized in Ionic Liquids: A Novel and Efficient Catalytic System for Michael Additions of Indoles to α,β–Unsaturated Ketones Pp. 414-418

Xufeng Lin, Sunliang Cui & Yanguang Wang Palladium(II) chloride immobilized in ionic liquid [bmim][BF4] catalyzes the Michael reaction of indoles with α,,β-unsaturated ketones to afford the corresponding β-indolylketones in excellent yields.

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