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Letters in Organic Chemistry
ISSN: 1570-1786
Letters in Organic Chemistry
Volume 4, Number 5, July 2007
Cycloaddition Reactions of 5-Hydroxymethyl-Furan–2-Nitrileoxide
Pp. 306-308
Ananda S. Amarasekara, Osayamen Edigin and Wendy Hernandez
[Abstract]
Synthesis of Oxepin-Annulated Quinolone Heterocycles
by Ruthenium Catalyzed Enyne Bond Reorganization/Diels-Alder
Reaction Pp. 309-313
Krishna C. Majumdar, Pradip Debnath and Srikanta Samanta
[Abstract]
Reversible Friedel–Crafts Acylations of Phenanthrene:
Rearrangements of Acetylphenanthrenes Pp. 314-318
Liron Levy, Sergey Pogodin, Shmuel Cohen and Israel Agranat
[Abstract]
A Mild Synthesis of Nitriles by TPPX2-promoted
Dehydration of Primary Amides Pp. 319-321
Daniele Vaccari, Paolo Davoli, Maria Bucciarelli, Alberto
Spaggiari and Fabio Prati
[Abstract]
A New Synthesis of Benzoazacrown Ethers Through Pd
Catalyzed Intramolecular Cycloamination Reactions
Pp. 322-324
Rafik Omar-Amrani, Raphaël Schneider and Yves Fort
[Abstract]
Microwave Accelerated Cross-Coupling Reaction of Arenediazonium
Tetrafluoroborates with Potassium Aryltrifluoroborates
Pp. 325-328
George W. Kabalka, Li-Li Zhou and Abhijit Naravane
[Abstract]
Thermal Degradation of Peptides and Formation of Acrylamide,
Part 2 Pp. 329-331
Jürgen Buhlert, Reinhold Carle, Zsuzsa Majer and
Dietrich Spitzner
[Abstract]
Eco-Friendly Synthesis and Biological Evaluation of
New Quinoline-Based Dialkyl α-Aminophosphonates
Pp. 332-338
Ljerka Tušek-Božic, Marina Juribašic, Marijana
Komac, Vesna Cmrecki, Irena Zrinski, Jan Balzarini and Erik
De Clercq
[Abstract]
Cation Binding Properties by Ammonium Glycolic and
Pyridinium Amido Calix[4]Arenes Pp. 339-343
Amel Ben Othman, Lassaad Baklouti, Rym Abidi and Jacques
Vicens
[Abstract]
Synthesis of 3-(Azolylmethylene)Chroman-4-ones via
Addition of Indoles and N-Methylpyrrole to 3-(Polyfluoroacyl)Chromones
Pp. 344-351
Vyacheslav Ya. Sosnovskikh and Roman A. Irgashev
[Abstract]
Palladium-Catalyzed Cyanation of Aryl Bromides with
Potassium Hexacyanoferrate (II) Pp. 352-356
Yi-nan Cheng, Zheng Duan, Ting Li and Yangjie Wu
[Abstract]
Microwave Accelerated Multicomponent Synthesis for
a Novel Scaffold of Monastrol Analogues Pp. 357-361
Mazaahir Kidwai, Suchi Kukreja, Shewta Rastogi and Kavita
Singhal
[Abstract]
Design and Synthesis of Hg2+
Sensing Probe Based on Spirobenzopyran Derivatives
Pp. 362-365
Tian Tian, Xiang Zhou and Wing H. Chan
[Abstract]
Syntheses of the Ammonium Salts of 7-Carbamate Derivatives
of Quercetin Pp. 366-369
Chenglong Wu, Li Cheng, Ying Li, Dong Guo, Shuyan Yu,
Xianxue Wu and Yuquan Wei
[Abstract]
Efficient Synthesis of 5H-Thiazolo[3,2-a]pyrimidines
from Reactions of 3,4-Dihydropyrimidine-thiones with α
Bromoacetone in Aqueous Media Pp. 370-373
Xi-Cun Wang, Zheng-Jun Quan, Zhang Zhang, Ya-Juan Liu
and Peng-Yan Ji
[Abstract]
Synthesis of meso-Aryl Substituted Porphyrins:
Simple and High Yielding Modification of the Adler Procedure
Pp. 374-377
Kamaljit Singh, Amit Sharma, Sonia Behal and Paramjit
Kaur
[Abstract]
Regioselective Synthesis of Biologically Important
Scaffold Spiro [Indole-Perimidines]: An Antitumor Agents
Pp. 378-383
Kapil Arya and Anshu Dandia
[Abstract]
Abstracts
[Back to top]
Cycloaddition Reactions of 5-Hydroxymethyl-Furan–2-Nitrileoxide
Ananda S. Amarasekara, Osayamen Edigin and Wendy Hernandez
5-Hydroxymethyl-furan-2-nitrileoxide undergoes [3+2] cycloadditions
with alkenes to give 3-(2-furanyl)-4,5-dihydo-isoxazole ring
system in 71-84% yield. Cycloaddition with one equivalent
of dimethylacetylene dicarboxylate gave a 1:1 adduct with
3-(2-furanyl)-isoxazole ring system and further reaction with
a second equivalent in a [4+2] Diels-Alder reaction yielded
a 3-(7-oxa-bicyclo[2.2.1]hepta-2,5-dien-1-yl)-isoxazole. Hydrogenolysis
of 3-(2-furanyl)-4,5-dihydo-isoxazole adducts with Raney-Ni
catalyst resulted the ring opening of the 4,5-dihydro-isoxazole
ring.
[Back to top]
Synthesis of Oxepin-Annulated Quinolone Heterocycles
by Ruthenium Catalyzed Enyne Bond Reorganization/Diels-Alder
Reaction
Krishna C. Majumdar, Pradip Debnath and Srikanta Samanta
Synthesis of oxepin-annulated quinolone heterocycles by the
combination of Claisen rearrangement, the ringclosing metathesis
and Diels-Alder reaction is described. The RCM or RCEM proceeded
smoothly in the presence of Grubbs’ first generation
catalyst at room temperature under nitrogen atmosphere.
[Back to top]
Reversible Friedel–Crafts Acylations of Phenanthrene:
Rearrangements of Acetylphenanthrenes
Liron Levy, Sergey Pogodin, Shmuel Cohen and Israel Agranat
The study of Friedel–Crafts acetylation of phenanthrene
with acetic acid in polyphosphoric acid, along with re-arrangements
and deacetylations of acetylphenanthrene isomers, indicated
its reversibility. The structures of (E)-2-AcPHN
and (Z)-9-AcPHN were determined by X-ray crystallography.
PM3 calculations predicted that 9-AcPHN is the kinetically
controlled while 2-AcPHN and 3-AcPHN are the thermodynamically
controlled products, in accordance with experiment. The mutual
rearrangements of 2-AcPHN and 9-AcPHN are noted.
[Back to top]
A Mild Synthesis of Nitriles by TPPX2-promoted
Dehydration of Primary Amides
Daniele Vaccari, Paolo Davoli, Maria Bucciarelli, Alberto
Spaggiari and Fabio Prati
An expeditious route to nitriles via dehydration
of primary amides using halotriphenoxy phosphonium halides
(TPPX2, X = Cl or Br) is
described. The reaction proceeds under very mild conditions
and allows the preparation of aromatic and aliphatic nitriles
in good to excellent yields.
[Back to top]
A New Synthesis of Benzoazacrown Ethers Through Pd
Catalyzed Intramolecular Cycloamination Reactions
Rafik Omar-Amrani, Raphaël Schneider and Yves Fort
A new synthesis of twelve-, fifteen-, and eighteen-membered
benzoazacrown ethers using palladium-catalyzed intramolecular
amination is reported. Couplings proceeded in good yields
using an in situ generated Pd(0) catalyst associated
to N,N’-bis(2,6-diisopropylphenyl)dihydroimidazol-2-ylidene
(SIPr) as ligand and t-BuONa as the base.
[Back to top]
Microwave Accelerated Cross-Coupling Reaction of Arenediazonium
Tetrafluoroborates with Potassium Aryltrifluoroborates
George W. Kabalka, Li-Li Zhou and Abhijit Naravane
A microwave enhanced ligand- and base-free protocol for the
cross-coupling of arenediazonium tetrafluoroborates with potassium
aryltrifluoroborates has been developed.
[Back to top]
Thermal Degradation of Peptides and Formation of Acrylamide,
Part 2
Jürgen Buhlert, Reinhold Carle, Zsuzsa Majer and
Dietrich Spitzner
The formation of acrylamide from asparagine and β-alanine
containing peptides without the involvement of an additional
carbonyl compound is described.
[Back to top]
Eco-Friendly Synthesis and Biological Evaluation of
New Quinoline-Based Dialkyl α-Aminophosphonates
Ljerka Tušek-Božic, Marina Juribašic, Marijana
Komac, Vesna Cmrecki, Irena Zrinski, Jan Balzarini and Erik
De Clercq
The eco-friendly synthesis and preliminary biological evaluation
of new dialkyl 2- and 3-quinoline-substituted α-aminophosphonates
have been described. The conventional and microwave-assisted
one- and two-steps reactions of the appropriate aromatic aldehyde,
amine and dialkyl phosphite, carried out without or in the
presence of solvent and catalyst, have been compared and discussed.
[Back to top]
Cation Binding Properties by Ammonium Glycolic and
Pyridinium Amido Calix[4]Arenes
Amel Ben Othman, Lassaad Baklouti, Rym Abidi and Jacques
Vicens
We report the binding properties of ammonium glycolic and
pyridinium amido calix[4]arenes towards alkali cations. UV
spectrophotometry titrations have been carried out in methanol
and acetonitrile. In one case the presence of the anions improves
the complexation compared to the neutral homologues.
[Back to top]
Synthesis of 3-(Azolylmethylene)Chroman-4-ones via
Addition of Indoles and N-Methylpyrrole to 3-(Polyfluoroacyl)Chromones
Vyacheslav Ya. Sosnovskikh and Roman A. Irgashev
Reactions of 3-(polyfluoroacyl)chromones with indole and N
methylindole in refluxing pyridine and N-methylpyrrole
under solvent-free conditions proceed at the C(2) atom of
the chromone system with pyrone ring opening and subsequent
cyclization to 2-hydroxy-3-(indol-3-ylmethylene- or pyrrol-2
ylmethylene)-2-(polyfluoroalkyl)chroman-4-ones in good yields.
Treatment of these compounds with morpholine gives trans-
indolyl(pyrrolyl)chalcones.
[Back to top]
Palladium-Catalyzed Cyanation of Aryl Bromides with
Potassium Hexacyanoferrate (II)
Yi-nan Cheng, Zheng Duan, Ting Li and Yangjie Wu
Simple and efficient cyclopalladated ferrocenylimine/Cu and
cyclopalladated ferrocenylimine catalyzed cyanation of aryl
bromides with K4[Fe(CN)6]·3H2O
were described. These procedures are applicable to both activated
and deactivated aryl bromides. The corresponding benzonitriles
were formed in good to excellent yields.
[Back to top]
Microwave Accelerated Multicomponent Synthesis for
a Novel Scaffold of Monastrol Analogues
Mazaahir Kidwai, Suchi Kukreja, Shewta Rastogi and Kavita
Singhal
A highly efficient and environmentally benign reaction of
dimedone with various aldehydes and N-arylthioureas
to afford monastrol analogues is revealed. The reaction is
found to be sensitive towards the steric and electronic effects
of the substituents in variable components. A quantitative
optimization of catalytic support is also presented.
[Back to top]
Design and Synthesis of Hg2+
Sensing Probe Based on Spirobenzopyran Derivatives
Tian Tian, Xiang Zhou and Wing H. Chan
A series of spirobenzopyran derivatives 9a-9c
bearing a dithiocarbamate/dithiocarbonate as the metal-ligating
group were designed for colormetric metal sensors and synthesized.
The binding properties of the sensors with different metal
ions were investigated. In terms of response time, selectivity
and sensitivity, sensor 9a showed a good
sensing ability toward mercury ion.
[Back to top]
Syntheses of the Ammonium Salts of 7-Carbamate Derivatives
of Quercetin
Chenglong Wu, Li Cheng, Ying Li, Dong Guo, Shuyan Yu,
Xianxue Wu and Yuquan Wei
A series of 7-carbamate derivatives of quercetin were synthesized.
Using dichlorodiphenylmethane and benzyl bromide to partly
protect the hydroxyl groups, the protected quercetin then
reacted with amino acid ester isocyanates, deprotection the
hydroxyls with hydrogen using a palladium on carbon catalyst,
then treating with ammonia gas to give the ammonium salts
of 7- carbamate derivatives of quercetin.
[Back to top]
Efficient Synthesis of 5H-Thiazolo[3,2-a]pyrimidines
from Reactions of 3,4-Dihydropyrimidine-thiones with α
Bromoacetone in Aqueous Media
Xi-Cun Wang, Zheng-Jun Quan, Zhang Zhang, Ya-Juan Liu
and Peng-Yan Ji
An efficient and convenient method for thiazolo[3,2-a]pyrimidines
from cyclization reaction of dihydropyrimidine- thiones with
α -bromoacetone
in aqueous media is described.
[Back to top]
Synthesis of meso-Aryl Substituted Porphyrins:
Simple and High Yielding Modification of the Adler Procedure
Kamaljit Singh, Amit Sharma, Sonia Behal and Paramjit
Kaur
An efficient single pot route is presented involving the use
of O,N-perhydro 1,3-heterocycles as carbonyl equivalents
for the synthesis of 5,5-disubstituteddipyrromethanes and
meso- tetraarylporphyrins through a high yielding
modified Adler route.
[Back to top]
Regioselective Synthesis of Biologically Important
Scaffold Spiro [Indole-Perimidines]: An Antitumor Agents
Kapil Arya and Anshu Dandia
Regioselective synthesis of spiro [indole -3(3H), 2′
(3H)perimidine]2′
(1H)one (4a-e) for potential application in cancer
treatment under conventionally and microwave irradiation using
different solvents/solid support has been studied. A judicious
choice of the reaction conditions allowed the titled product
4a-e to be generated in excellent yields. |
