Letters in Organic Chemistry, Volume 1, No. 1, 2004
Contents
Synthesis and Isomerization of 3-Pyrroline Enamines Pp.1-5
A.
Gilbert Cook, Karen A. Switek, Kenneth A. Cutler and Allison M. Witt
[Abstract]
Two-Dimensional Porphyrin Array Assembled by
Self-Coordination Pp.6-11
Satoshi
Morikawa, Chusaku Ikeda, Kazuya Ogawa
and Yoshiaki Kobuke
[Abstract]
The Photochemical Isomerization of Pyrazoles: An AB
Initio Study Pp.12-19
Maurizio
D’Auria and Rocco Racioppi
[Abstract]
Regioselective Diels-Alder Reactions of 3-Vinylindoles
with Quinones Pp.20-22
Miguel
Angel Alonso, Pilar Lopez-Alvarado, Carmen Avendano and J. Carlos Menendez
[Abstract]
Ring Versus Nitrogen Protonation of Anilines Pp.23-30
Robert
Flammang, Noemie Dechamps, Laurent Pascal, Yves Van Haverbeke, Pascal Gerbaux,
Pham-Cam Nam and Minh Tho Nguyen
[Abstract]
Novel Anthraquinone-Carbohydrate Hybrids: The
Significant Improvement of the DNA Photocleaving Activity and the Cytotoxic
Kazunobu
Toshima, Yoko Nakajima, Yutaka Maeda and Shuichi Matsumura
[Abstract]
New DNA Intercalating Acridinic Ligands: Comparative Copper-Catalyzed
N-Arylation Reactions of 4-Aminoacridine with Organobismuth,
Kamal
Shimi, Gerard Boyer, Jean-Pierre Finet and Jean-Pierre Galy
[Abstract]
An Efficient Synthesis of Hexahydro Oxaisoindolo[2,1-α]Quinoline
Derivatives via the Diels-Alder Reactions Pp.37-39
Vladimir
V. Kouznetsov, Fedor I. Zubkov, Uriel Mora Cruz, Leonid G. Voskressensky,
Leonor
Y. Vargas Mendez, Luis Astudillo
and Elena E. Stashenko
[Abstract]
Metal Mediated Dechlorination – A New Route to Nitriles Pp.40-42
V.K.
Tandona and R.B. Chhor
[Abstract]
Indium(I) Iodide-Mediated Regioselective Ring Opening
of Epoxides with Diphenyldiselenide: The Preparation of β-Hydroxy
Selenides Pp.43-46
O.S.
do Rego Barros, A.B. de Carvalho, E.S. Lang and C. Peppe
[Abstract]
Microwave-Accelerated Epoxidation of α,β-Unsaturated
Ketones with Urea- Hydrogen Peroxide
Pp.47-49
Alcindo
A. dos Santos, Edison P. Wendler, Francisco de A. Marques and Fabio Simonelli
[Abstract]
Microwave-Assisted Synthesis of
2,5-Disubstituted-1,3,4-Oxadiazoles
Pp.50-52
Khalid
Mohammed Khan, Zia-Ullah, Mubeen Rani, Shahnaz Perveen, Syed Moazzam Haider,
Muhammad Iqbal Choudhary, Atta-ur-Rahman
and Wolfgang Voelter
[Abstract]
From the MARDi Cascade to the Stereoselective
Construction of Functionalized Bicyclo[5.4.0]undecene Skeletons Occurring in
Natural Compounds Pp.53-54
M.-H.
Filippini and J. Rodriguez
[Abstract]
A General Access to 2-Silylthiazolidines and Their
Reactions Under Fluoride Ion Conditions Pp.55-58
Antonella
Capperucci, Alessandro Degl’Innocenti, Tiziano Nocentini, Alessandro Mordini,
Simona Biondi and Francesca Dini
[Abstract]
Synthesis of 8,16-Ethanoretinals and Their Interactions
with Apoprotein of Phoborhodopsin from Natronobacterium pharaonis Pp.59-62
Akimori
Wada, Yoshimi Takakura, Kenta Yamazaki, Tetsuo Takahashi and Masayoshi Ito
[Abstract]
Asymmetric 1,3-Dipolar Cycloaddition of Chiral α,β-Unsaturated-g-Sultams with Nitrile Oxides and Nitrones Pp.63-66
H.
Zhang, W.H. Chan, Albert W.M. Lee, P.-F. Xia and W.Y. Wong
[Abstract]
Synthesis of N-Aryl Indolines from 2-Fluorobenzaldehyde
Dimethylhydrazone Derivatives: Approach to Preparation of C(aryl)-N(Amine)
Bond Atropisomeric Amines Pp.67-69
Takashi
Mino, Youichi Tanaka, Youtaro Hattori, Motoko Tanaka, Masami Sakamoto and
Tsutomu Fujita
[Abstract]
Generation of Oxygen-, Sulfur, Carbon-, Nitrogen- and
Phosphorus- Centred Short-Lived Radicals Via One-Electron Oxidation
with Stable Hydrazyl Radical Pp.70-74
P.
Ionita, B.C. Gilbert and A.C. Whitwood
[Abstract]
Synthesis of New Ligands Derived from Polyphosphonates
Partial Esters Pp.75-77
Pascale
Even, Erwann Guenin, Mounya Benramdame, Patricia Quidu, Driss El Manouni and
Marc Lecouvey
[Abstract]
Total Synthesis of the 13,13 Difluoro Analog of the 13
HODE Pp.78-80
E.
Kerouredan, M. Prakesch, D. Gree and R. Gree
[Abstract]
Catalytic, Asymmetric Synthesis of Cyanohydrin Esters:
The Effect of Anhydride Structure on Enantioselectivity Pp.81-83
Y.N.
Belokon, P. Carta and M. North
[Abstract]
Synthesis of Bisquaternary Symmetric –
χ,δ-Bis(2-Hydroxyiminomethylpyridinium) Alkane Dibromides and Their
Reactivation of Cyclosarin-Inhibited Acetylcholinesterase Pp.84-86
[Abstract]
The Application of Quantitative Analytical Constructs
for Chemistry Optimization, Monomer Rehearsal and Reactivity Prediction in
Solid Phase
Nigel
J. Parr, Stephen C. McKeown, Mika K. Lindvall, Olivier E. Lorthioir, Miles S.
Congreve and Stephen P. Watson
[Abstract]
Syntheses and Biological Activities of Novel N-tert-butyl-N′-Alkoxycarbonyl-
N-Substituted Benzoylhydrazines and their Derivatives
Pp.93-98
Qingmin
Wang and Runqiu Huang
[Abstract]
A New Approach to (2S, 3S,
4S)-3-Hydroxy-4-Methylproline, A Subunit in Echinocandin B and Related Oligopeptide
Antibiotics Pp.99-101
P.-Q.
Huang and W.-H. Meng
[Abstract]
Isoquinoline Alkaloids from Duguetia Vallicola
Stem Bark with Antiplasmodial Activity
Pp.102-104
E.
Perez, J. Saez, S. Blair, X. Franck
and B. Figadere
[Abstract]
Abstracts
[Back to top] Synthesis and Isomerization of 3-Pyrroline Enamines
A.
Gilbert Cook, Karen A. Switek, Kenneth A. Cutler and Allison M. Witt
[Full text article]
3-Pyrroline reacts with cyclic ketones to form enamines as kinetically controlled products. Under more vigorous conditions, pyrroles are formed as thermodynamically controlled products by way of a 1,3-hydride shift.
[Back to top] Two-Dimensional Porphyrin Array Assembled by
Self-Coordination
Satoshi
Morikawa, Chusaku Ikeda, Kazuya Ogawa
and Yoshiaki Kobuke
A novel cross-shaped porphyrin pentamer having four imidazolyl-porphyrinatozinc(II) moieties, one at each meso-position, was prepared. AFM measurements confirmed the formation of a large two-dimensional porphyrin array structure: a thin layer of 6~7 porphyrins was assembled over a 350 ´ 350nm2 area, representing linkage of approximately 120 pentamer units along the line of the cross.
[Back to top] The Photochemical Isomerization of Pyrazoles: An AB
Initio Study
Maurizio
D’Auria and Rocco Racioppi
The photochemical isomerization of pyrazoles was studied using ab initio methods. The singlet excited singlet state can evolve to give the Dewar isomer and the corresponding triplet state. The latter shows a lower energy and probably can be obtained with higher efficiency. The triplet state can evolve to give the corresponding 1,2-biradical and, then, the isomerization product. The same behavior was obtained by using 1,5-dimethylpyrazole. However, 1-methyl-5-phenylpyrazole gave a different behavior. The triplet state cannot evolve to give the corresponding biradical. The isomerization product can be obtained only from the Dewar isomer.
[Back to top] Regioselective Diels-Alder Reactions of 3-Vinylindoles
with Quinones
Miguel
Angel Alonso, Pilar Lopez-Alvarado, Carmen Avendano and J. Carlos Menendez
The Diels-Alder reactions of in situ generated vinylindoles and several non-symmetrical quinones, such as 2,5,8(1H)-quinolinetriones and 6-bromoquinolinequinones, were found to be regioselective.
[Back to top] Ring
Versus Nitrogen Protonation of Anilines
Robert Flammang, Noemie Dechamps, Laurent Pascal, Yves
Van Haverbeke, Pascal Gerbaux, Pham-Cam Nam and Minh Tho Nguyen
[Full text article]
Ionization of mixtures of halogenobenzenes and ammonia under chemical ionization conditions affords isomeric (N or C4) protonated anilines. The N-protonated species are dominantly produced by ion-molecule reactions of mass-selected ionized halogenobenzenes with ammonia or in electrospray conditions. Quantum chemical calculations confirm that the N-protonation in aniline is marginally favored, by about 4 kJ mol-1, over the C4-protonation.
[Back to top] Novel
Anthraquinone-Carbohydrate Hybrids: The Significant Improvement of the DNA
Photocleaving Activity and the Cytotoxic
Kazunobu Toshima, Yoko Nakajima,
Yutaka Maeda and Shuichi Matsumura
[Full text article]
Novel anthraquinone-carbohydrate hybrids were designed and synthesized as artificial DNA photocleavers. They were found to show high DNA cleaving activity under irradiation with a long wavelength UV light without any additives and also exhibited selective cytotoxicity against HeLa S3 cancer cells with the photoirradiation.
[Back to top] New
DNA Intercalating Acridinic Ligands: Comparative Copper-Catalyzed N-Arylation
Reactions of 4-Aminoacridine with Organobismuth, Organoboron and Organolead
Compounds
Kamal Shimi, Gerard Boyer,
Jean-Pierre Finet and Jean-Pierre Galy
[Full text article]
Copper diacetate catalyzed phenylation of 4-aminoacridine afforded the N-phenyl derivative in good yields with triphenylbismuth diacetate, moderate yields with phenylboronic acid and failed with in situ generated phenyllead triacetate. All systems gave high yields of the N-monophenyl derivative in their reaction with 3,4-dimethylaniline.
[Back to top] An
Efficient Synthesis of Hexahydro Oxaisoindolo[2,1-α]Quinoline
Derivatives via the Diels-Alder Reactions
Vladimir
V. Kouznetsov, Fedor I. Zubkov, Uriel Mora Cruz, Leonid G. Voskressensky,
Leonor Y. Vargas Mendez, Luis Astudillo
and Elena E. Stashenko
[Full text article]
The straightforward synthesis of new carboxylic acids with hexahydro-oxaisoindolo[2,1-a]quinoline core from the 2,4-disustituted 1,2,3,4-tetrahydroquinolines bearing a furan fragment via the intramolecular Diels-Alder reaction has been proposed. It was demonstrated that synthesis of key precursors can be realized with excellent level of diastereoselectivity either by imino-Diels-Alder reaction or multi-component condensation approach.
[Back to top] Metal
Mediated Dechlorination – A New Route to Nitriles
V.K. Tandona and R.B. Chhor
[Full text article]
1,4-Dichloro-1,4-disubstituted-2,3-diaza-1,3-butadiene 1 undergo cyclodechlorination in presence of Be metal to form cyclazines 3a. Reaction of 1 with Cu, Zn and Mn metals results in formation of nitriles 2. Cyclazines 3 on further oxidation with H2O2 in CH3COOH form NO donors, 1,2-dioxides 4.
[Back to top]Indium(I)
Iodide-Mediated Regioselective Ring Opening of Epoxides with Diphenyldiselenide:
The Preparation of β-Hydroxy
Selenides
O.S. do Rego Barros, A.B. de
Carvalho, E.S. Lang and C. Peppe
[Full text article]
Epoxides were efficiently transformed into b-hydroxy selenides by the action of diphenyldiselenide and indium(I) iodide under mild conditions. The ring opening reaction is regioselective with nucleophile incorporation at the less hindered carbon atom for alkyl-substituted epoxides, and at the benzylic carbon atom for aryl derivatives.
[Back to top] Microwave-Accelerated
Epoxidation of α,β-Unsaturated
Ketones with Urea- Hydrogen Peroxide
Alcindo A. dos Santos, Edison
P. Wendler, Francisco de A. Marques
and Fabio Simonelli
[Full text article]
The reaction time needed to perform the epoxidation of several a, b-unsaturated ketones with urea-hydrogen peroxide were substantially reduced by means of microwave irradiation. This environmental friendly protocol showed to be very useful, especially to effect the epoxidation of sterically hindered substrates.
[Back to top] Microwave-Assisted
Synthesis of 2,5-Disubstituted-1,3,4-Oxadiazoles
Khalid Mohammed Khan, Zia-Ullah,
Mubeen Rani, Shahnaz Perveen, Syed Moazzam Haider, Muhammad Iqbal Choudhary,
Atta-ur-Rahman and Wolfgang Voelter
[Full text article]
Recent advances in technology have now made microwave energy a more efficient means of heating reactions. Chemical transformations that took hours, or even days, to complete can now be accomplished in minutes. Microwave energy offers numerous benefits for performing synthesis including increased reaction rates, yield enhancements, and cleaner chemistries. 2,5-Disubstituted-1,3,4-oxadiazoles were synthesized under microwave irradiation and by conventional heating and were structurally characterized by 1H-NMR, EI, IR, UV and elemental analysis.
[Back to top] From the
MARDi Cascade to the Stereoselective Construction of Functionalized
Bicyclo[5.4.0]undecene Skeletons Occurring in Natural Compounds
M.-H. Filippini and J. Rodriguez
[Full text article]
The stereoselective construction of functionalized bicyclo[5.4.0]undecene systems, found in many natural sesquiterpenes such as in the widdrane, guadalupane, and recently isolated guanacastepene families, is achieved by selective chemical transformations of a functionalized cycloheptanol arising from the MARDi cascade.
[Back to top] A General
Access to 2-Silylthiazolidines and Their Reactions Under Fluoride Ion
Conditions
Antonella
Capperucci, Alessandro Degl’Innocenti, Tiziano Nocentini, Alessandro
Mordini, Simona Biondi and Francesca Dini
[Full text article]
The stereoselective construction of functionalized bicyclo[5.4.0]undecene systems, found in many natural sesquiterpenes such as in the widdrane, guadalupane, and recently isolated guanacastepene families, is achieved by selective chemical transformations of a functionalized cycloheptanol arising from the MARDi cascade.
[Back to top] Synthesis
of 8,16-Ethanoretinals and Their Interactions with Apoprotein of Phoborhodopsin
from Natronobacterium pharaonis
Akimori
Wada, Yoshimi Takakura, Kenta Yamazaki, Tetsuo Takahashi and Masayoshi Ito
[Full text article]
Several 8,16-Ethanoretinals 3 were synthesized from cyclohexanones. From the binding experiments of these analogs with apoprotein of phoborhodopsin, it was found that retinal was incorporated as 6s-trans conformation in the protein and the fine structure in absorption spectra of pigments were dependent on the coplanarity of the conjugated polyene structure in the chromophore.
[Back to top] Asymmetric
1,3-Dipolar Cycloaddition of Chiral α,β-Unsaturated-g-Sultams with Nitrile Oxides and Nitrones
H.
Zhang, W.H. Chan, Albert W.M. Lee, P.-F. Xia and W.Y. Wong
[Full text article]
The scope and limitations of 1,3-dipolar cycloaddition reactions between nitrile oxides and chiral a,b-unsaturated-g-sultams 2a and 2b have been investigated. Only very marginal diastereoselectivity was observed for the reaction. In contrast, using double asymmetric induction strategy, the cycloaddition products from 2a and chiral nitrones were obtained in better diastereomeric ratios (up to 7.1:1).
[Back to top] Synthesis
of N-Aryl Indolines from 2-Fluorobenzaldehyde Dimethylhydrazone Derivatives:
Approach to Preparation of C(aryl)-N(Amine) Bond Atropisomeric Amines
Takashi
Mino, Youichi Tanaka, Youtaro Hattori, Motoko Tanaka, Masami Sakamoto and
Tsutomu Fujita
2-(1-indolinyl)benzaldehyde dimethylhydrazones are prepared by nucleophilic aromatic substitution of the corresponding 2-fluorobenzaldehyde dimethylhydrazones with lithiated indoline in good yields.
[Back to top] Generation
of Oxygen-, Sulfur, Carbon-, Nitrogen- and Phosphorus- Centred Short-Lived
Radicals Via One-Electron Oxidation with Stable Hydrazyl Radical
P. Ionita, B.C. Gilbert and A.C. Whitwood
[Full text article]
Using three readily-prepared free-radicals of DPPH type, with different oxidation potential, it is possible to generate, via one electron transfer or hydrogen-atom abstraction, short-lived radicals, characterised by the EPR spintrapping technique. PBN, DMPO and DEPMPO were employed as spin-traps. The results show that DPPH and its congeners can be successfully employed for generation of short-lived oxygen-, sulfur-, carbon-, nitrogen-, and phosphorus-centered radicals.
[Back to top] Synthesis
of New Ligands Derived from Polyphosphonates Partial Esters
Pascale Even, Erwann Guenin, Mounya Benramdame, Patricia
Quidu, Driss El Manouni and Marc Lecouvey
[Full text article]
In the search for new chelation therapy drugs for the treatment of metal intoxications, some new polyphosphonated chelating ligands have been synthesized. They were obtained by means of an Arbuzov reaction followed by addition of the corresponding dialkylphosphite. The regioselective dealkylation was then carried out by using trimethylsilyl halide.
[Back to top] Total
Synthesis of the 13,13 Difluoro Analog of the 13 HODE
E. Kerouredan, M. Prakesch, D. Gree and R. Gree
[Full text article]
The first total synthesis of the 13,13 difluoro analog of 13 HODE, via the novel fluorinated synthons (5) and (2), is reported. The key advantages of using a propargylic route for the introduction of the gem difluoro moiety are highlighted below.
[Back to top] Catalytic,
Asymmetric Synthesis of Cyanohydrin Esters: The Effect of Anhydride Structure
on Enantioselectivity
Y.N. Belokon, P.
Carta and M. North
[Full text article]
A bimetallic titanium(salen) complex has been shown to catalyse the asymmetric addition of potassium cyanide to aldehydes in the presence of a range of anhydrides, leading to cyanohydrin esters. Linear aliphatic anhydrides (acetic and propionic) gave products with higher enantiomeric purity than those obtained using pivalic or benzoic anhydrides.
[Back to top] Synthesis
of Bisquaternary Symmetric – χ,δ-Bis(2-Hydroxyiminomethylpyridinium) Alkane
Dibromides and Their Reactivation of Cyclosarin-Inhibited Acetylcholinesterase
Kamil Kuca, Jiri Cabal, Jiri Patocka and Jiri Kassa
[Full text article]
Preparations of the symmetric bisquaternary oximes – 1,4-bis(2-hydroxyiminomethypyridinium) butane dibromide and 1,3-bis(2-hydroxyiminomethypyridinium)propane dibromide, and their abilities to reactivate cyclosarin-inhibited acetylcholinesterase are described. Common reactivator (pralidoxime) was used as a standard for comparison of the reactivation efficacy. The first oxime seems to be very good reactivator of cyclosarin-inhibited acetylcholinesterase.
[Back to top] The
Application of Quantitative Analytical Constructs for Chemistry Optimization,
Monomer Rehearsal and Reactivity Prediction in Solid Phase Library Synthesis
Nigel J. Parr, Stephen C. McKeown, Mika K. Lindvall, Olivier
E. Lorthioir, Miles S. Congreve and
Stephen P. Watson
[Full text article]
The use of quantitative dual linker analytical constructs for the high-throughput generation of solid phase reaction data is described. This methodology can be applied to chemistry optimization, monomer rehearsal and monomer reactivity prediction as a tool to aid the production of solid phase compound libraries.
[Back to top] Syntheses
and Biological Activities of Novel N-tert-butyl-N′-Alkoxycarbonyl-
N-Substituted Benzoylhydrazines and their Derivatives
Qingmin Wang and Runqiu Huang
[Full text article]
A series of novel N-tert-butyl-N¢-alkoxycarbonyl-N-substitutedbenzoylhydrazines and their derivatives were synthesized. The results of bioassay showed that these title compounds exhibit moderate larvicidal activities, and toxicity assays indicated that these title compounds can induce a premature, abnormal and lethal larval molt. At the same time, we found by chance that these title compounds possess potential anticancer activities in vitro.
[Back to top] A New
Approach to (2S, 3S, 4S)-3-Hydroxy-4-Methylproline, A Subunit in Echinocandin B
and Related Oligopeptide Antibiotics
P.-Q. Huang and
W.-H. Meng
[Full text article]
A new approach to two protected forms of (2S, 3S, 4S)-3-hydroxy-4-methylproline, a constituent of echinocandins and related oligopeptide antibiotics is reported. The method features a highly regioselective and diastereoselective reductive furylation of protected (2S, 3S)-3-methylmalimide and a chemoselective oxidative transformation of furyl to carboxyl as the key steps.
[Back to top] Isoquinoline
Alkaloids from Duguetia Vallicola Stem Bark with Antiplasmodial Activity
E. Perez, J. Saez, S. Blair, X. Franck and B. Figadere
[Full text article]
Duguevalline (1), a novel aporphinoid alkaloid, in addition to four known alkaloids, cleistopholine (2), O-methylmoschatoline (3), (-)-oliveroline (4) and (-)-oliveridine (5), were isolated and characterized from Duguetia vallicola stems. Structural elucidation of these compounds was established by spectroscopic methods. Among them, alkaloids (2) and (4) exhibited antiplasmodial activity against Plasmodium falciparum.