| Letters
in Organic Chemistry
ISSN: 1570-1786
Letters in Organic Chemistry
Volume 2, Number 1, February 2005
Contents
The Catalytic Version of Stoichiometric Organic
Synthesis Pp. 5-14
Hideki Amii
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A Simple, High Yield Route to cis-4-(N-Alkylamino)-L-Prolines
Pp.15-17
Timothy P. Curran, Kevin A. Marques and Segufta I. Bilimoria
[Abstract] [Purchase
Article]
First Efficient One-Pot Synthesis of Tetrahydropyrrolo[2,3-d]azocines
and Tetrahydroazocino[4,5-b]indoles Pp. 18-20
Leonid G.Voskressensky, Tatiana N. Borisova, Tatiana A.
Soklakova, Larisa N. Kulikova, Roman S. Borisov and Alexej
V. Varlamov
[Abstract] [Purchase
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Enantiopure Bicyclic Piperidinones: Stereocontrolled
Cycloadditions Pp. 21-24
A.G. Brewster, S. Broady, E. Glenn, S.A. Hermitage,
M. Hughes, M.G. Moloney and G. Woods
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A Caveat on the Use of 2-Chloro-4,6-dimethoxy-1,3,5-triazine
for the Synthesis of 4,4-Dimethyl-2-R-2-Oxazolines Pp.
25-28
Robert A. Gossage and Amber L. Sadowy
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Synthesis and Transformations of New Spiro-4-piperidines.
Acetyl Migration in 1-Acetyl-1’-Benzyl-4-Methyl-3,4-Dihydrospiro[(1H)quinoline-2,4’-piperidines]
Under Debenzylation Conditions Pp. 29-32
Vladimir V. Kouznetsov, Basilio Diaz P., Clara Marcela
Sanabria M., Leonor Y. Vargas M., Juan Carlos Poveda, Elena
E. Stashenko, Ali Bahsas and Juan Amaro-Luis
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Article]
Chiral Acetylenic Sulfoxide in Organic Synthesis:
Addition of Chiral Secondary Amines Pp. 33-36
Sujun Yan, K.T. Lam, K.T. Mo, W.Y. Wong, W.H. Chan and
Albert W.M. Lee
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Nucleophilic Carbenes of Pyrazoles Starting from
Pseudo-Cross-Conjugated Mesomeric Betaines Pp. 37-39
Andreas Schmidt and Tobias Habeck
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Article]
Reaction Systems Peripheral to the 1:2 Mannich
Condensation Reaction between o-Phthalaldehyde and Primary
Amine Pp. 40-43
I. Takahashi, K. Nishiuchi, R. Miyamoto, M. Hatanaka,
H. Uchid, K. Isa, A. Sakushima and S. Hosoi
[Abstract] [Purchase
Article]
One-Pot, Regioselective Synthesis of 1,3,5 Trisubstituted
Hydantoins by Domino Condensation/aza-Michael/O?N acyl Migration
of Asymmetric Carbodiimides with a,b-Unsaturated Carboxylic
Acids Pp. 44-46
Alessandro Volonterio and Matteo Zanda
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Fused 1,3-oxazolidine-2-thiones on Ketohexose
Backbones: Functional Modulation Processes Pp. 47-50
Arnaud Tatibouet, Ana C. Simao and Patrick Rollin
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Article]
Why has Cerium (III) Triflate been Forgotten Among
the Catalysts for the Friedel-Crafts Acylation? Pp.
51-53
Giuseppe Bartoli, Antonio De Nino, Renato Dalpozzo, Loredana
Maiuolo, Monica Nardi, Antonio Procopio and Antonio Tagarelli
[Abstract] [Purchase
Article]
A Novel Mechanism of Specificity of Response in
Ratiometric Fluorescence Sensing of d10 Metal Ions Pp.
54-56
Scott A. Van Arman, Thomas M. Sisk and David M. Zawrotny
[Abstract] [Purchase
Article]
A Remarkable Zirconium(IV) Chloride Catalyzed
Highly Selective Deprotection of t-Butyldimethylsilyl (TBS)
Ethers in Presence of t-Butyldiphenylsilyl (TPS) Ethers Pp.
57-60
G.V.M. Sharma, B. Srinivas and Palakodety Radha Krishna
[Abstract] [Purchase
Article]
Chemoselective Carbonyl Benzylation Mediated by
Zn/CdCl2/InCl3 in Tap Water Pp. 61-64
Cunliu Zhou, Jiaoyang Jiang, Yuqing Zhou, Zhen Xie, Qian
Miao and Zhiyong Wang
[Abstract] [Purchase
Article]
Enantioselective Copper-catalysed Conjugate Addition
of Diphenylzinc to Cyclohexenone Pp. 65-67
Xiao-yu Wu, Xiang-guo Li and Gang Zhao
[Abstract] [Purchase
Article]
A DFT Analysis of the Strain-Induced Regioselective[2+2]Cycloaddition
of Benzyne Possessing Fused Four-Membered Ring Pp.
68-73
L.R. Domingo, P. Perez and R. Contreras
[Abstract] [Purchase
Article]
Model Studies Towards Alternative Cross-Linking
of Unsaturated Polyesters Pp. 74-76
Thomas Straub, Martin Brunner and Ari M.P. Koskinen
[Abstract] [Purchase
Article]
Imidazolium Dichromate Adsorbed on Alumina: A
Convenient and Inexpensive Reagent for the Cleavage of C=N
Functionalities Pp. 77-78
Surya Kanta De
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Article]
A Simple Approach to DC-Cholesterol, its Analogues
and Vitamin D-Based Cationic Lipids for Gene Therapy Pp.
79-82
Armandodoriano Bianco, Francesco Bonadies, Raffaella Napolitano
and Giancarlo Ortaggi
[Abstract] [Purchase
Article]
Design and Synthesis of a New Furanosic Sialylmimetic
as a Potential Influenza Neuraminidase Viral Inhibitor Pp.
83-88
A. Bianco, M. Brufani, D.A. Dri, C. Melchioni and L. Filocamo
[Abstract] [Purchase
Article]
Baker's Yeast Reduction of PEG-Linked Acetoacetate
Pp. 89-91
G.M. Bonora, S. Drioli, C. Forzato, P. Nitti
and G. Pitacco
[Abstract] [Purchase
Article]
Abstracts
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The Catalytic Version of Stoichiometric Organic Synthesis
Hideki Amii
This short review focuses on the impressive examples of endeavors
to make stoichiometric reactions catalytic. The strategies
employed encompass the reuse of waste coproducts to achieve
the catalytic cycles and to reduce the amounts of reagents
of the transformations. Several methodologies for in situ
regeneration of active agents are highlighted.
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Article]
A Simple, High Yield Route to cis-4-(N-Alkylamino)-L-Prolines
Timothy P. Curran, Kevin A. Marques and Segufta
I. Bilimoria
Reaction of 1 equivalent of N-a-acetyl-cis-4-azido-L-proline
with 1 equivalent of an aldehyde and a catalytic amount of
Pd-C under an H2 atmosphere cleanly and efficiently yields
the corresponding N-a-acetyl-cis-4-(N-?-alkylamino)-L-proline
derivative.
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Article]
First Efficient One-Pot Synthesis of Tetrahydropyrrolo[2,3-d]azocines
and Tetrahydroazocino[4,5-b]indoles
Leonid G.Voskressensky, Tatiana N. Borisova,
Tatiana A. Soklakova, Larisa N. Kulikova, Roman S. Borisov
and Alexej V. Varlamov
A new efficient one-pot protocol for the synthesis of tetrahydropyrrolo[2,3-d]azocines
and tetrahydroazocino[4,5-b]indoles starting from ready-available
tetrahydropyrrolo[3,2-c]pyridines and tetrahydropyrido[4,3-b]indoles
correspondingly and dimethylacetylene dicarboxylate or ethyl
propiolate is being offered.
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Article]
Enantiopure Bicyclic Piperidinones: Stereocontrolled Cycloadditions
A.G. Brewster, S. Broady, E. Glenn, S.A. Hermitage,
M. Hughes, M.G. Moloney and G. Woods
The cycloadditions of a [4.3.0]-bicyclic a,b-unsaturated
lactam, derived from 6-oxopipecolic acid, have been investigated.
Although yields are modest, diastereoselectivity is high;
reasons for the low reactivity are postulated, based on experimental
observations and molecular modelling.
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Article]
A Caveat on the Use of 2-Chloro-4,6-dimethoxy-1,3,5-triazine
for the Synthesis of 4,4-Dimethyl-2-R-2-Oxazolines
Robert A. Gossage and Amber L. Sadowy
The reported synthesis of 4,4-dimethyl-2-R-2-oxazolines from
carboxylic acids and 2-amino-2-methyl-1-propanol (1) using
2-chloro-4,6-dimethoxy-1,3,5-triazine (2) via direct coupling/cyclisation
is questioned. The results reported herein indicate that the
products are actually w–hydroxyamides resulting from
dehydrative R-COOH/1 (peptide) coupling only, which has been
known to be mediated by 2 for some time.
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Synthesis and Transformations of New Spiro-4-piperidines.
Acetyl Migration in 1-Acetyl-1’-Benzyl-4-Methyl-3,4-Dihydrospiro[(1H)quinoline-2,4’-piperidines]
Under Debenzylation Conditions
Vladimir V. Kouznetsov, Basilio Diaz P., Clara
Marcela Sanabria M., Leonor Y. Vargas M., Juan Carlos Poveda,
Elena E. Stashenko, Ali Bahsas and Juan Amaro-Luis
Synthesis of new dihydrospiro[quinoline-2,4’-piperidines]
by a two-step synthetic route based on 4-piperidone imine
reactivity is reported. An acetyl migration in 1-acetyl-1’-benzyl-4-methyl-3,4-
dihydrospiro[quinoline-2,4’-piperidines] under debenzylation
conditions (HCOONH4/Pd/C/MeOH) is found.
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Article]
Chiral Acetylenic Sulfoxide in Organic Synthesis:
Addition of Chiral Secondary Amines
Sujun Yan, K.T. Lam, K.T. Mo, W.Y. Wong, W.H.
Chan and Albert W.M. Lee
Chiral secondary amines of the 3,4-dimethoxyphenylethyl and
the tryptamine system were reacted with chiral acetylenic
sulfoxides and achiral acetylenic sulfone. In the case of
3,4-dimethoxyphenylethyl amine, much improved diastereoselectivity
(96 : 4) was observed as compared to the reaction of achiral
secondary amine with chiral acetylenic sulfoxides.
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Nucleophilic Carbenes of Pyrazoles Starting from Pseudo-Cross-Conjugated
Mesomeric Betaines
Andreas Schmidt and Tobias Habeck
Pyrazolium-3-carboxylates, which belong to the class of pseudo-cross-conjugated
heterocyclic mesomeric betaines, decarboxylate to give nucleophilic
carbenes, which can be trapped as pyrazolium salts. An aldol
addition, a Knoevenagel reaction, and a Cannizzaro-type reaction
are presented, which are initiated by the strong basicity
of the in situ generated pyrazol-3-ylidene.
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Reaction Systems Peripheral to the 1:2 Mannich Condensation
Reaction between o-Phthalaldehyde and Primary Amine
I. Takahashi, K. Nishiuchi, R. Miyamoto, M. Hatanaka,
H. Uchid, K. Isa, A. Sakushima and S. Hosoi
Reaction systems peripheral to the 1:2 condensation reaction
between o-phthalaldehyde and primary amine were studied. Newly
identified were 1,3-dihydroxyisoindoline, o-iminomethylbenzaldehyde
and o-amidiniobenzoate, the last of which exhibited moderate
anticancer activity.
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Article]
One-Pot, Regioselective Synthesis of 1,3,5 Trisubstituted
Hydantoins by Domino Condensation/aza-Michael/O?N acyl Migration
of Asymmetric Carbodiimides with a,b-Unsaturated Carboxylic
Acids
Alessandro Volonterio and Matteo Zanda
1,3,5 Trisubstituted hydantoins having two different substituents
at the nitrogen atoms could be smoothly prepared by a domino
condensation/aza-Michael/O?N acyl migration of asymmetric
carbodiimides with activated a,b-unsaturated carboxylic acids.
The regiochemical outcome of the process, as well as scope
and limits, are discussed.
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Article]
Fused 1,3-oxazolidine-2-thiones on Ketohexose Backbones: Functional
Modulation Processes
Arnaud Tatibouet, Ana C. Simao and Patrick Rollin
1,3-Oxazolidine-2-thiones fused to ketohexose backbone were
prepared from 1-O-, 1-N- or 1-S-derivatives in reasonable
yields. Spontaneous ring closure leads to spiro-tricyclic
unexpected aminal and amide structures.
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Article]
Why has Cerium (III) Triflate been Forgotten Among the Catalysts
for the Friedel-Crafts Acylation?
Giuseppe Bartoli, Antonio De Nino, Renato Dalpozzo,
Loredana Maiuolo, Monica Nardi, Antonio Procopio and Antonio
Tagarelli
Cerium is the less rare "rare earth"; its salts
are commercially available and inexpensive. However, screening
of lanthanide triflates as Lewis acid catalysts in the Friedel-Crafts
acylation of aromatics skipped cerium triflate. Now, catalytic
Friedel-Crafts acylations of activated benzenes are performed
by using cerium (III) triflate as catalyst. For less activated
arenes, addition of lithium perchlorate as co-catalyst is
required. In all cases aromatic ketones are obtained in very
good yields.
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Article]
A Novel Mechanism of Specificity of Response in Ratiometric
Fluorescence Sensing of d10 Metal Ions
Scott A. Van Arman, Thomas M. Sisk and David
M. Zawrotny
In a 25% methanolic aqueous solution the metal ion specificity
of ratiometric fluorescence response of a bis-anthrylpolyamine
host is increased versus a purely aqueous medium. It is proposed
that the geometry of the host, metal ion size, and hydrophobicity
work in concert to give the geometry leading to excimer fluorescence.
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Article]
A Remarkable Zirconium(IV) Chloride Catalyzed Highly Selective
Deprotection of t-Butyldimethylsilyl (TBS) Ethers in Presence
of t-Butyldiphenylsilyl (TPS) Ethers
G.V.M. Sharma, B. Srinivas and Palakodety Radha
Krishna
A highly selective and efficient method for the chemoselective
deprotection of t-butyldimethylsilyl (TBS) ethers using 20
mol% of zirconium(IV) chloride as Lewis acid in isopropanol
is reported. Remarkable selectivity was observed towards the
TBS group deprotection while TPS remains unaffected. The reaction
is fast and the conditions are tolerable to a variety of protecting
groups, carbohydrates and terpenes. The products are obtained
in excellent yields.
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Chemoselective Carbonyl Benzylation Mediated by Zn/CdCl2/InCl3
in Tap Water
Cunliu Zhou, Jiaoyang Jiang, Yuqing Zhou, Zhen
Xie, Qian Miao and Zhiyong Wang
A novel trimetal system (Zn/CdCl2/InCl3) has been developed
as an effective mediator in the benzylations of various aldehydes
in tap water to afford the corresponding alcohols. It can
selectively mediate the benzylation of aldehyde in the presence
of ketone. CdCl2 and InCl3 are easily recycled and used in
this reaction without further purification.
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Enantioselective Copper-catalysed Conjugate Addition of Diphenylzinc
to Cyclohexenone
Xiao-yu Wu, Xiang-guo Li and Gang Zhao
The copper-catalysed asymmetric conjugate addition of diphenylzinc
to 2-cyclohexenone has been carried out with good results.
An enantiometric excess of up to 91% was obtained using 5
mol% CuI and 5 mol% phosphine ligand derived from L-proline.
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A DFT Analysis of the Strain-Induced Regioselective[2+2]Cycloaddition
of Benzyne Possessing Fused Four-Membered Ring
L.R. Domingo, P. Perez and R. Contreras
The regioselective [2+2] cycloaddition of a substituted benzyne
possessing a fused four-membered ring to a ketene acetal has
been theoretically studied. This cycloaddition presents a
two-step mechanism that is initiated by the nucleophilic attack
to the benzyne to give a zwitterionic intermediate. The analysis
performed on the basis of the global and local electrophilicity
of reagents correctly explain the observed reactivity and
regioselectivity in this system.
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Model Studies Towards Alternative Cross-Linking of Unsaturated
Polyesters
Thomas Straub, Martin Brunner and Ari M.P. Koskinen
Fumaric and maleic acid esters are functionalised with propargylamine.
A subsequent Pd/Cucatalysed oxidative homo-coupling of two
alkyne moieties yields the corresponding dimers. Hence, a
model of an unsaturated polyester chain is cross-linked in
a well-defined, metal-mediated reaction in a very high yield.
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Article]
Imidazolium Dichromate Adsorbed on Alumina: A Convenient and
Inexpensive Reagent for the Cleavage of C=N Functionalities
Surya Kanta De
Oximes, hydrazones and semicarbazones are converted to the
corresponding carbonyl compounds using imidazolium dichromate
adsorbed on alumina (IDC/alumina).
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Article]
A Simple Approach to DC-Cholesterol, its Analogues and Vitamin
D-Based Cationic Lipids for Gene Therapy
Armandodoriano Bianco, Francesco Bonadies, Raffaella
Napolitano and Giancarlo Ortaggi
An improved synthesis of DC-Cholesterol, its analogues and
Vitamin D-based lipids for the preparation of liposomes in
gene therapy, is described. This synthetic strategy affords
significative increase in the yields of DC-Cholesterol and
its analogs.
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Design and Synthesis of a New Furanosic Sialylmimetic
as a Potential Influenza Neuraminidase Viral Inhibitor
A. Bianco, M. Brufani, D.A. Dri, C. Melchioni
and L. Filocamo
A furanosic derivative has been identified as a simple sialylmimetic
and synthesized, representing the first step in the development
of a new series of furanosic sialic acid’s mimetics
as potential inhibitors of influenza virus neuraminidase.
The structure was tested on a molecular simulating environment
before proceeding with synthetic pathways.
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Baker's Yeast Reduction of PEG-Linked Acetoacetate
G.M. Bonora, S. Drioli, C. Forzato, P. Nitti
and G. Pitacco
Bioreduction of PEG-acetoacetate 1 is achieved using dry
baker's yeast in toluene with a small amount of added water.
After detachment from the polymer under basic conditions,
the corresponding (S)-(+)- 3-hydroxybutanoic acid 3 was esterified
with Me3SiCl and ethanol and ethyl (S)-(+)-3-hydroxybutanoate
4 was isolated with 97% e.e. and 70% overall yield.
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