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Letters in Organic Chemistry
ISSN: 1570-1786
Letters in Organic Chemistry
Volume 7, Number 1, January 2010
Contents
Graphical
Abstracts Pp.i-v
Pd/C-Catalyzed Cross-Coupling of Arenediazonium Salts with
Potassium Aryltrifluoroborates Pp. 1-6
Lee S. Varnedoe, Brad D. Angel, Joshua L.
McClellan and James M. Hanna, Jr.
[Abstract] [Purchase
Article]
The Nitrile Functionality as a Directing
Group in the Palladium-Catalysed Addition of Aryl Boronic
Acids to Alkynes Pp. 7-10
Arantxa Rodriguez and Wesley J.
Moran
[Abstract] [Purchase
Article]
Homocoupling Reaction of Aryl Boronic
Acids Catalyzed by Pd(OAc)2/
K2CO3
in Water under Air Atmosphere Pp.
11-14
Nan Wu, Xinnian Li, Xin Xu, Yumei Wang,
Yunyun Xu and Xi Chen
[Abstract] [Purchase
Article]
Editor’s Choice
Direct Asymmetric Aldol Reaction Catalyzed by C2-Symmetrical
Chiral Primary Amine Organocatalysts Pp. 15-20
Gong-Jian Zhu, Chao-Shan Da, Ya-Ning Jia,
Xiao Ma and Lei Yi
[Abstract] [Purchase
Article]
Studies on Aldol Reactions of Nortropinone
Derivatives in Solution and on Solid Phase Pp. 21-26
Ryszard Lazny, Aneta Nodzewska and Michal
Sienkiewicz
[Abstract] [Purchase
Article]
An Environment-Friendly and Efficient
Method for Aldol Condensation Catalyzed by L-Lysine in Pure
Water Pp. 27-31
Yan Zhang, Man Gang Wang, Jun Liang and
Zhi Cai Shang
[Abstract] [Purchase
Article]
Synthesis of 2,3 and 4,5-Dihydro-hydroxy-isoxazoles
and Isoxazoles Under Different pH Conditions Pp.
32-38
Virginie Andrzejak, Régis Millet,
Jamal El Bakali, Abdelhalim Guelzim, Sebastien Gluszok, Philippe
Chavatte, Jean-Paul Bonte, Claude Vaccher and Emmanuelle
Lipka
[Abstract] [Purchase
Article]
Esterification of Unprotected α-Amino
Acids in Ionic Liquids as the Reaction Media Pp.
39-44
Daniele Biondini, Lucia Brinchi, Raimondo
Germani, Laura Goracci and Gianfranco Savelli
[Abstract] [Purchase
Article]
A New Practical Synthesis of Linezolid:
An Antibacterial Drug Pp. 45-49
Ganta M. Reddy, Akula Ramulu and
Padi P. Reddy
[Abstract] [Purchase
Article]
A New Approach to Tubacin Pp.
50-53
Jian Hong, Xin Xu, Debasis Das, Pengyu Yang,
Shu-Hui Chen and Ge Li
[Abstract] [Purchase
Article]
Iodoalkene-Based Approach Towards Carboxamides
of Biological Importance: Aminocarbonylation of 2-Iodobornene
and 3-Iodo-2-quinuclidene Pp. 54-60
László Horváth, Andrea
Petz and László Kollár
[Abstract] [Purchase
Article]
InCl3•4H2O-Catalyzed
Trioxane as a New Methylating Agent for multi-Methylated
Aromatics Affording Hexamethyl Benzene Pp. 61-63
Song-Jie Chen and Ruimao Hua
[Abstract] [Purchase
Article]
A Cheap Amino Alcohol Catalyzed One-Pot,
Tri-Component Synthesis of Tetrahydrochromene Derivatives
Pp. 64-68
Shaojun Song, Zixing Shan and Yong
Jin
[Abstract] [Purchase
Article]
Diastereoselective Synthesis of γ-Phthalimido-β-Hydroxy
Esters and N-Protected 4-Amino-1,3-Diols Starting
from Natural α-Amino
Acids Pp. 69-72
Amel Essersi, Ridha Touati and
Béchir Ben Hassine
[Abstract] [Purchase
Article]
Natural Amino Acid-Based Ionic Liquids as Efficient Catalysts
for the Synthesis of Cyclic Carbonates from CO2
and Epoxides under Solvent-Free Conditions Pp.
73-78
Fang Wu, Xiao-Yong Dou, Liang-Nian He and
Cheng-Xia Miao Pp.
[Abstract] [Purchase
Article]
Thienopyridone Antibacterials. Part IV[1].
Synthesis of Some N(7)-Heteroaryl-4-oxothieno[2,3-b]pyridine-5-carboxylic
Acids and Esters Pp. 79-84
Nuha I. Sweidan, Musa Z. Nazer, Mustafa
M. El-Abadelah and Wolfgang Voelter
[Abstract] [Purchase
Article]
The Synthesis of Octyl-Substituted Hexathia[7]heterohelicene
Based on dithieno[2,3-b:3',2'-d]thiophene
via Irradiation Pp. 85-89
Zhihua Wang, Jianwu Shi, Chunli Li,
Dongfeng Zhao, Zhen Wang and Hua Wang
[Abstract] [Purchase
Article]
Direct Functionalization of Benzoquinolines
Pp. 90-93
Victor Mamane, Frédéric
Louërat and Yves Fort
[Abstract] [Purchase
Article]
Abstracts
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Article]
Pd/C-Catalyzed Cross-Coupling of Arenediazonium Salts with
Potassium Aryltrifluoroborates
Lee S. Varnedoe, Brad D. Angel, Joshua L.
McClellan and James M. Hanna, Jr.
A convenient protocol for the synthesis of biaryls from
arenediazonium salts and potassium aryltrifluoroborates in
refluxing methanol catalyzed by Pd/C is described. The protocol
is simple to execute and gives moderate to high yields of
cross-coupling products in most cases.
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[Purchase Article]
The Nitrile Functionality as a Directing Group in the Palladium-Catalysed
Addition of Aryl Boronic Acids to Alkynes
Arantxa Rodriguez and Wesley J.
Moran
The nitrile group is shown to direct the palladium-catalysed
hydroarylation of internal alkynes bearing a pendant nitrile
with boronic acids.
[Back to top] [Purchase
Article]
Homocoupling Reaction of Aryl Boronic Acids Catalyzed by Pd(OAc)2/
K2CO3
in Water under Air Atmosphere
Nan Wu, Xinnian Li, Xin Xu, Yumei Wang,
Yunyun Xu and Xi Chen
Moderate to good yields of symmetrical biaryls were obtained
under environmental friendly conditions via homocoupling
reaction of aryl boronic acids catalyzed by Pd(OAc)2
/ K2CO3
in water. Our method explores the synthetic utility of the
homocoupling reaction of aryl boronic acids which may provide
a simple and general alternative to the Suzuki reaction to
achieve symmetrical biaryls.
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Article]
Direct Asymmetric Aldol Reaction Catalyzed
by C2-Symmetrical
Chiral Primary Amine Organocatalysts
Gong-Jian Zhu, Chao-Shan Da, Ya-Ning Jia,
Xiao Ma and Lei Yi
Three novel C2-symmetrical
chiral primary amines were synthesized from chiral BINOL and
diamines. Then their catalytic activities in the asymmetric
aldol reactions were evaluated, and the result indicated that
1c was the optimal organocatalyst. The reaction
of a variety of aromatic aldehydes with aliphatic ketones,
catalyzed by 20 mol % 1c in the addition
of benzoic acid in carbon tetrachloride, afforded the aldol
products in high yields (up to 92%) and good enantioselectivities
(up to 71%).
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Article]
Studies on Aldol Reactions of Nortropinone Derivatives in
Solution and on Solid Phase
Ryszard Lazny, Aneta Nodzewska and Michal
Sienkiewicz
Polymer-anchored (Merrifield, trityl chloride, Wang
p-nitrophenyl carbonate and triazene supports) nortropinone,
or N-protected nortropinone derivatives in solution,
were subjected to deprotonation with LDA or chiral lithium
amides, and the resulting lithium enolates were trapped with
an aldehyde. The aldols were obtained with moderate to good
yields (44-84%) and enantioselectivities (44-86% ee).
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Article]
An Environment-Friendly and Efficient Method for Aldol
Condensation Catalyzed by L-Lysine in Pure Water
Yan Zhang, Man Gang Wang, Jun Liang
and Zhi Cai Shang
This is a new example of a nonmetallic small-molecule
catalyst for direct intermolecular aldol reactions. We found
L-lysine is an effective catalyst for this condensation between
unmodified acetone and a variety of aldehydes in the presence
of pure water. This green catalyst system could be reused.
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Article]
Synthesis of 2,3 and 4,5-Dihydro-hydroxy-isoxazoles and Isoxazoles
Under Different pH Conditions
Virginie Andrzejak, Régis Millet,
Jamal El Bakali, Abdelhalim Guelzim, Sebastien Gluszok, Philippe
Chavatte, Jean-Paul Bonte, Claude Vaccher and Emmanuelle
Lipka
Reaction between aryl 1,3-diketoesters 2a-e
and hydroxylamine hydrochloride has been investigated under
different experimental conditions. Whereas acid conditions
gave principally 3,5-isoxazole esters (3a-e),
reactions under neutral and basic conditions led to different
4,5 and 2,3-dihydro-hydroxy-isoxazoles 4a-e
and 5a-e.
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Article]
Esterification of Unprotected α-Amino
Acids in Ionic Liquids as the Reaction Media
Daniele Biondini, Lucia Brinchi, Raimondo
Germani, Laura Goracci and Gianfranco Savelli
Ionic liquid 1,3-dimethylimidazolium methanesulfonate
was used to prepare α-amino
acids benzylic esters from unprotected amino acids and benzyl
chloride. Esterification of several amino acids was achieved
with satisfactory yields: by-products can be removed by a
simple work-up procedure to afford the pure product. The described
method is simple, mild, rapid and save.
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Article]
A New Practical Synthesis of Linezolid: An Antibacterial Drug
Ganta M. Reddy, Akula Ramulu and
Padi P. Reddy
A novel and practical asymmetric synthesis of (S)-N-[[3-(3-fluoro-4-morpholinyl
phenyl)-2-oxo-5-oxazo-lidinyl]methyl]acetamide has been developed
by a new approach without recourse to chromatography and it
is employed for the synthesis of Linezolid. This involves
the reaction of (R)-epichlorohydrin with N-arylcarbamates
and subsequent regioselective epoxide ring opening of resulted
intermediate by sodium azide.
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Article]
A New Approach to Tubacin
Jian Hong, Xin Xu, Debasis Das, Pengyu Yang,
Shu-Hui Chen and Ge Li
A new simple synthesis of tubacin is reported. It entails
the formation of the syn-1,3-diol unit and its stereoselective
ketalization with a functionalized benzaldehyde derivative
[Back to top]
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Article]
Iodoalkene-Based Approach Towards Carboxamides of Biological
Importance: Aminocarbonylation of 2-Iodobornene and 3-Iodo-2-quinuclidene
László Horváth, Andrea
Petz and László Kollár
The palladium-catalysed aminocarbonylation of 2-iodobornene
and 3-iodo-2-quinuclidene, possessing iodo alkene functionality,
resulted in the high-yielding synthesis of the corresponding
carboxamide derivatives. The substrates were synthesised from
camphor and 3-quinuclidone, respectively, via their
hydrazones. The chemoselective homogeneous carbonylation reaction
of synthetic value was carried out under mild reaction conditions.
While the carbonylation of the 2-iodobornene was found to
be a facile reaction with yields of synthetic interest, its
isomer, 1-iodocamphene, formed in Wagner-Meervein rearrangement,
remained intact under the same reaction conditions.
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Article]
InCl3•4H2O-Catalyzed
Trioxane as a New Methylating Agent for multi-Methylated
Aromatics Affording Hexamethyl Benzene
Song-Jie Chen and Ruimao Hua
In the presence of a catalytic amount of Cl3•4H2O,
trioxane was first used as the methylating agent for multi-methylated
aromatic compounds such as pentamethylbenzene, 1,2,4,5-tetramethylbenzene
and 1,3,5-trimethylbenzene to afford hexamethylbenzene in
fair to high yields.
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Article]
A Cheap Amino Alcohol Catalyzed One-Pot, Tri-Component Synthesis
of Tetrahydrochromene Derivatives
Shaojun Song, Zixing Shan and Yong
Jin
An economic, efficient access to 4H-chromene
derivatives was found. In the presence of threo-(1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediol,
a chiral “waste” in the production of chloromycetin,
and one-pot three-component Hantzsch reaction of dimedone,
aldehydes and malononitrile at room temperature furnished
4H-pyran derivatives in good to excellent yield.
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Article]
Diastereoselective Synthesis of γ-Phthalimido-β-Hydroxy
Esters and N-Protected 4-Amino-1,3-Diols Starting
from Natural α-Amino
Acids
Amel Essersi, Ridha Touati and
Béchir Ben Hassine
An efficient diastereoselective synthes.is of
γ-Phthalimido-β-hydroxy
esters and N-protected 4-amino-1,3-diols, starting
from natural amino acids is described. The key synthetic strategies
involve diastereoselective reduction of γ-Phthalimido-β-keto
esters with NaBH4 as hydride
reducing. The diastereoselective reduction has been found
to be highly selective if carried out in methanol at -78°C.
Furthermore, the resulting diastereomeric mixture of the reduced
products was successfully and cleanly separated by column
chromatography.
[Back to top]
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Article]
Natural Amino Acid-Based Ionic Liquids as Efficient Catalysts
for the Synthesis of Cyclic Carbonates from CO2
and Epoxides under Solvent-Free Conditions
Fang Wu, Xiao-Yong Dou, Liang-Nian He and
Cheng-Xia Miao
Natural α-amino
acids-derived ionic liquids comprising 1-butyl-3-methylimidazolium
cation and amino acid anion, i.e. [bmim][AA] were found to
be effective catalysts for the coupling of various epoxides
and CO2 to produce cyclic
carbonates in good yields and selectivity, which requires
no additional organic solvent and avoids halogen.
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Article]
Thienopyridone Antibacterials. Part IV[1]. Synthesis of Some
N(7)-Heteroaryl-4-oxothieno[2,3-b]pyridine-5-carboxylic
Acids and Esters
Nuha I. Sweidan, Musa Z. Nazer, Mustafa
M. El-Abadelah and Wolfgang Voelter
A series of 7-heteroaryl-4-oxo-4,7-dihydrothieno[2,3-b]-pyridine-5-carboxylic
acids (8a-d) and their methyl esters (7a-d)
were prepared by cyclization of the respective 2-(2,5-dichlorothien-3-yl)-3-(N-heteroarylamino)acrylates
(6a-d). The latter are accessible from methyl
2-(2,5-dichlorothien-3-yl)-3-ethoxyacrylate (5)
which is obtained via methyl 3-(2,5-dichlorothien-3-yl)-3-oxopropanoate(4).
Of the present series, the 7-(2-thienyl) derivative (8a)
exhibited good activity, especially against E. coli
and Kl. pneumoniae (MIC = 2 μg
/ mL).
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Article]
The Synthesis of Octyl-Substituted Hexathia[7]heterohelicene
Based on dithieno[2,3-b:3',2'-d]thiophene
via Irradiation
Zhihua Wang, Jianwu Shi, Chunli Li, Dongfeng
Zhao, Zhen Wang and Hua Wang
With 2-octyl dithieno[2,3-b:3',2'-d]thiophene
as raw material, three steps including formylation, McMurry
reaction and photocylization were employed to generate dioctyl-hexathia[7]heterohelicene
in total yield of 29.9%. The crystal analysis shows that some
short intermolecular interactions including S…S and
C…S interactions were observed in the crystal of target
compound.
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Direct Functionalization of Benzoquinolines
Victor Mamane, Frédéric
Louërat and Yves Fort
The first direct lithiation of the pyridine ring of benzo[h]-
and benzo[f]- quinolines is reported. The method
allowed the introduction of different electrophiles (Cl, Br
and SPh) in 2-position. Other groups were introduced by direct
nucleophilic addition of alkyllithiums allowing further transformations
to functional groups such as esters and thiolesters.
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