Pub Date : 2012-01-19DOI: 10.2174/1874095201206010001
Lydie Harmand, Samer Saleh, J. Andrieu, H. Cattey, M. Picquet, Jean‐Cyrille Hierso
Several novel palladium triphosphine complexes have been synthesized and tested as recyclable catalysts for the methoxylation of alkynes into acetals in ionic liquids. A complete conversion of phenylacetylene was achieved with only 0.2% of (Pd(Triphos)NCMe)((PF6)2) in a methanol/(BMIM)(BF4) mixture. We discovered that the addition of an ionic liquid to methanol allowed not only to increase the activity of the palladium catalyst but also to provide a recyclable catalyst which can be reused several times with a weaker drop of activity. To complete these catalytic studies, we describe the synthesis of the first poor -electron-donating/strong -electron-acceptor linear Triphosphine which, after palladium coordination, led to a better selectivity compared to its Triphos analogue. The performances of recovered ionic liquid re- action mixtures show for the first time that P-tridentate ligands efficiently immobilize palladium catalysts and lead to se- lective catalytic systems benign for environment.
{"title":"Linear Triphosphines as Ligands for Metal Complexes Immobilization in Ionic Liquids: Palladium-Catalyzed Methoxylation of Alkynes","authors":"Lydie Harmand, Samer Saleh, J. Andrieu, H. Cattey, M. Picquet, Jean‐Cyrille Hierso","doi":"10.2174/1874095201206010001","DOIUrl":"https://doi.org/10.2174/1874095201206010001","url":null,"abstract":"Several novel palladium triphosphine complexes have been synthesized and tested as recyclable catalysts for the methoxylation of alkynes into acetals in ionic liquids. A complete conversion of phenylacetylene was achieved with only 0.2% of (Pd(Triphos)NCMe)((PF6)2) in a methanol/(BMIM)(BF4) mixture. We discovered that the addition of an ionic liquid to methanol allowed not only to increase the activity of the palladium catalyst but also to provide a recyclable catalyst which can be reused several times with a weaker drop of activity. To complete these catalytic studies, we describe the synthesis of the first poor -electron-donating/strong -electron-acceptor linear Triphosphine which, after palladium coordination, led to a better selectivity compared to its Triphos analogue. The performances of recovered ionic liquid re- action mixtures show for the first time that P-tridentate ligands efficiently immobilize palladium catalysts and lead to se- lective catalytic systems benign for environment.","PeriodicalId":23020,"journal":{"name":"The Open Organic Chemistry Journal","volume":"20 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2012-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75034100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-12-14DOI: 10.2174/1874095201105010127
S. Kamila, Haribabu Ankati, Kimberly Mendoza, E. Biehl
Pyridobenzimidazoles 6a-iwere synthesized in very good to excellent yields (81-96%) by the condensation of substituted N-phenyl-o-phenylenediamines 4a-d with indole/benzo(b)thiophene-3-aldehydes 5a-t inmethoxyethanol under reflux conditions. The diamines 4a-d were prepared byfirst treating 2-chloro-3-nitropyridine (1)with suitably substituted anilines 2a-d then reducing the resulting3-nitro-N-phenylpyridin-2-amines 3a-d with tin(II)chloride using microwave heating in each case.
以取代的n -苯基-邻苯二胺4a-d与吲哚/苯并(b)噻吩-3醛5a-t为原料，在回流条件下以81-96%的收率合成了吡并并咪唑6a- 1。首先用适当取代的苯胺2-a -d处理2-氯-3-硝基吡啶(1)，然后用氯化锡(II)微波加热还原得到3-硝基-n -苯基吡啶-2-胺3- a-d，制备了4 -a -d二胺。
{"title":"Synthesis of Novel Pyridobenzimidazoles Bonded to Indoleorbenzo[b]thio-phenestructures","authors":"S. Kamila, Haribabu Ankati, Kimberly Mendoza, E. Biehl","doi":"10.2174/1874095201105010127","DOIUrl":"https://doi.org/10.2174/1874095201105010127","url":null,"abstract":"Pyridobenzimidazoles 6a-iwere synthesized in very good to excellent yields (81-96%) by the condensation of substituted N-phenyl-o-phenylenediamines 4a-d with indole/benzo(b)thiophene-3-aldehydes 5a-t inmethoxyethanol under reflux conditions. The diamines 4a-d were prepared byfirst treating 2-chloro-3-nitropyridine (1)with suitably substituted anilines 2a-d then reducing the resulting3-nitro-N-phenylpyridin-2-amines 3a-d with tin(II)chloride using microwave heating in each case.","PeriodicalId":23020,"journal":{"name":"The Open Organic Chemistry Journal","volume":"25 5 1","pages":"127-134"},"PeriodicalIF":0.0,"publicationDate":"2011-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74585799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-09-12DOI: 10.2174/1874364101105010087
Fuji Zhang, Xiaofeng Guo, Heping Zhang
Clar's aromatic sextet theory provides a good means to describe the aromaticity of benzenoid hydrocarbons, which was mainly based on experimental observations. Clar defined sextet pattern and Clar number of benzenoid hydrocarbons, and he observed that for isomeric benzenoid hydrocarbons, when Clar number increases the absorption bands shift to shorter wavelength, and the stability of these isomers also increases. Motivated by Clar's aromatic sextet theory, three types of polynomials (sextet polynomial, Clar polynomial, and Clar covering polynomial) were defined, and Randić 's conjugated circuit model was also established. In this survey we attempt to review some advances on Clar's aromatic sextet theory and Randić 's conjugated circuit model in the past two decades. New applications of these polynomials to fullerenes, and calculation methods of linear independent and minimal conjugated circuit polynomials of benzenoid hydrocarbons are also presented.
{"title":"Advances of Clar's Aromatic Sextet Theory and Randic´'s Conjugated Circuit Model","authors":"Fuji Zhang, Xiaofeng Guo, Heping Zhang","doi":"10.2174/1874364101105010087","DOIUrl":"https://doi.org/10.2174/1874364101105010087","url":null,"abstract":"Clar's aromatic sextet theory provides a good means to describe the aromaticity of benzenoid hydrocarbons, which was mainly based on experimental observations. Clar defined sextet pattern and Clar number of benzenoid hydrocarbons, and he observed that for isomeric benzenoid hydrocarbons, when Clar number increases the absorption bands shift to shorter wavelength, and the stability of these isomers also increases. Motivated by Clar's aromatic sextet theory, three types of polynomials (sextet polynomial, Clar polynomial, and Clar covering polynomial) were defined, and Randić 's conjugated circuit model was also established. In this survey we attempt to review some advances on Clar's aromatic sextet theory and Randić 's conjugated circuit model in the past two decades. New applications of these polynomials to fullerenes, and calculation methods of linear independent and minimal conjugated circuit polynomials of benzenoid hydrocarbons are also presented.","PeriodicalId":23020,"journal":{"name":"The Open Organic Chemistry Journal","volume":"46 1","pages":"87-111"},"PeriodicalIF":0.0,"publicationDate":"2011-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87804374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-09-12DOI: 10.2174/1874364101105010112
Jerry Ray Dias
Coronoids with holes shaped like an odd carbon benzenoid have antiaromatic holes and antiaromatic conju- gated circuits. Another class of concealed diradical coronoids has been identified. They are Huckel molecular orbital dira- dicals (HOMO = LUMO = 0, each with a single electron occupancy) that have VB (valence-bond) structures (K � 0).This new class of concealed diradical coronoids have more enhanced antiaromatic contributions. The smallest holes in graphe- nes are spin polarized and have antiaromatic characteristics.
{"title":"Concealed Coronoid Hydrocarbons with Enhanced Antiaromatic Circuit Contributions as Models for Schottky Defects in Graphenes","authors":"Jerry Ray Dias","doi":"10.2174/1874364101105010112","DOIUrl":"https://doi.org/10.2174/1874364101105010112","url":null,"abstract":"Coronoids with holes shaped like an odd carbon benzenoid have antiaromatic holes and antiaromatic conju- gated circuits. Another class of concealed diradical coronoids has been identified. They are Huckel molecular orbital dira- dicals (HOMO = LUMO = 0, each with a single electron occupancy) that have VB (valence-bond) structures (K � 0).This new class of concealed diradical coronoids have more enhanced antiaromatic contributions. The smallest holes in graphe- nes are spin polarized and have antiaromatic characteristics.","PeriodicalId":23020,"journal":{"name":"The Open Organic Chemistry Journal","volume":"15 1","pages":"112-116"},"PeriodicalIF":0.0,"publicationDate":"2011-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85984288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-09-12DOI: 10.2174/1874364101105010079
Israel Fernández, G. Frenking
We discuss the results of selected projects where we estimate the strength of aromatic stabilization with the help of the Energy Decomposition Analysis within the Density Functional Theory framework. The paper introduces a new methodology to quantify the relative strength of aromaticity in aromatic and antiaromatic organic compounds. The ap- proach is also useful for the study of homo(anti)aromatic systems and for compounds where the traditional methods do not give a consistent answer concerning their aromatic character such as small-ring compounds and metallabenzenes.
{"title":"Direct Estimate of Aromaticity with the Energy Decomposition Analysis","authors":"Israel Fernández, G. Frenking","doi":"10.2174/1874364101105010079","DOIUrl":"https://doi.org/10.2174/1874364101105010079","url":null,"abstract":"We discuss the results of selected projects where we estimate the strength of aromatic stabilization with the help of the Energy Decomposition Analysis within the Density Functional Theory framework. The paper introduces a new methodology to quantify the relative strength of aromaticity in aromatic and antiaromatic organic compounds. The ap- proach is also useful for the study of homo(anti)aromatic systems and for compounds where the traditional methods do not give a consistent answer concerning their aromatic character such as small-ring compounds and metallabenzenes.","PeriodicalId":23020,"journal":{"name":"The Open Organic Chemistry Journal","volume":"1 1","pages":"79-86"},"PeriodicalIF":0.0,"publicationDate":"2011-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88832607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-09-12DOI: 10.2174/1874364101105010062
T. Gribanova, R. M. Minyaev, V. Minkin
Structures and stability of an extended series of bipyramidal, sandwich and sandwich-bipyramidal mixed complexes formed by conjugated cyclic hydrocarbons (CH)n with s(Li, Na, K, Be, Mg, Ca) and d(Cr, Mn, Fe) metals have been studied using DFT B3LYP/6-311+G(df,p) calculations. Stable structures of the compounds satisfy a general (6n + 6d + 12c) electron-count rule, where n stands for total number of the basal hydrocarbon rings, d is total number of d-metal centers (or separate sandwich moieties) and is total number of apical metal-carbonyl groups. It is shown that stabilization of the studied polyhedral organometallic structures (induced aromaticity) is caused by filling 6 -electronic shells of basal (4-6)-membered cycles provided by donation of additional electrons from metal centers thereby acquiring closed 18-
{"title":"Induced Aromaticity and Electron-Count Rules for Bipyramidal and Sandwich Complexes of s- and d-Metals","authors":"T. Gribanova, R. M. Minyaev, V. Minkin","doi":"10.2174/1874364101105010062","DOIUrl":"https://doi.org/10.2174/1874364101105010062","url":null,"abstract":"Structures and stability of an extended series of bipyramidal, sandwich and sandwich-bipyramidal mixed complexes formed by conjugated cyclic hydrocarbons (CH)n with s(Li, Na, K, Be, Mg, Ca) and d(Cr, Mn, Fe) metals have been studied using DFT B3LYP/6-311+G(df,p) calculations. Stable structures of the compounds satisfy a general (6n + 6d + 12c) electron-count rule, where n stands for total number of the basal hydrocarbon rings, d is total number of d-metal centers (or separate sandwich moieties) and is total number of apical metal-carbonyl groups. It is shown that stabilization of the studied polyhedral organometallic structures (induced aromaticity) is caused by filling 6 -electronic shells of basal (4-6)-membered cycles provided by donation of additional electrons from metal centers thereby acquiring closed 18-","PeriodicalId":23020,"journal":{"name":"The Open Organic Chemistry Journal","volume":"24 1","pages":"62-78"},"PeriodicalIF":0.0,"publicationDate":"2011-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80188074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-06-03DOI: 10.2174/1874095201105010001
C. Fàbrega, S. Grijalvo, R. Eritja
The use of benzoyl, isobutyryl and dimethylaminomethylidene groups for the protection of the exocyclic amino function of 2-aminopurine during oligonucleotide synthesis has been investigated. Best results in the synthesis were ob- tained with the monomers of 2-aminopurine protected with the isobutyryl group.
{"title":"Synthesis and Properties of Oligodeoxynucleotides Carrying 2-Aminopurine","authors":"C. Fàbrega, S. Grijalvo, R. Eritja","doi":"10.2174/1874095201105010001","DOIUrl":"https://doi.org/10.2174/1874095201105010001","url":null,"abstract":"The use of benzoyl, isobutyryl and dimethylaminomethylidene groups for the protection of the exocyclic amino function of 2-aminopurine during oligonucleotide synthesis has been investigated. Best results in the synthesis were ob- tained with the monomers of 2-aminopurine protected with the isobutyryl group.","PeriodicalId":23020,"journal":{"name":"The Open Organic Chemistry Journal","volume":"64 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2011-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88273887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-29DOI: 10.2174/1874095201004010015
J. Domínguez-Chávez, Sandra Cortez-Maya, I. Moggio, E. Arias-Marín, T. Klimova, I. Lijanova, M. Martínez-García
C60 pyrene anthrylvinylene triads were synthesized with good yields by an O-alkylation reaction of pyrene an- thracene chloride derivatives and functionalized fullerene C60. The presence of lateral butoxy chains imparts good solubil- ity. The NMR data indicate the formation of only the trans isomers. After C60 cyclopropanation, the UV-Vis spectra show the pyrene electronic transition with an absorption band extending from 400 to 800 nm due to the combination of the electronic transition of the antrylvinylene moiety and the C60 band, regardless the extension of the anthrylvinylene moiety. However, the emission is almost mirror-like with respect to the absorption bands of pyrene, suggesting that the HOMO and LUMO are more localized on this substituent. All the obtained compounds were characterized by 1 H and 13 C NMR,
{"title":"Double Molecular Antenna Pyrene – Bridge - Fullerene C60","authors":"J. Domínguez-Chávez, Sandra Cortez-Maya, I. Moggio, E. Arias-Marín, T. Klimova, I. Lijanova, M. Martínez-García","doi":"10.2174/1874095201004010015","DOIUrl":"https://doi.org/10.2174/1874095201004010015","url":null,"abstract":"C60 pyrene anthrylvinylene triads were synthesized with good yields by an O-alkylation reaction of pyrene an- thracene chloride derivatives and functionalized fullerene C60. The presence of lateral butoxy chains imparts good solubil- ity. The NMR data indicate the formation of only the trans isomers. After C60 cyclopropanation, the UV-Vis spectra show the pyrene electronic transition with an absorption band extending from 400 to 800 nm due to the combination of the electronic transition of the antrylvinylene moiety and the C60 band, regardless the extension of the anthrylvinylene moiety. However, the emission is almost mirror-like with respect to the absorption bands of pyrene, suggesting that the HOMO and LUMO are more localized on this substituent. All the obtained compounds were characterized by 1 H and 13 C NMR,","PeriodicalId":23020,"journal":{"name":"The Open Organic Chemistry Journal","volume":"50 1","pages":"15-23"},"PeriodicalIF":0.0,"publicationDate":"2010-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80168081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-09-03DOI: 10.2174/1874095201004010008
R. Mohareb, R. Ibrahim, H. Moustafa
{"title":"Hydrazide-Hydrazones in the Synthesis of 1,3,4-Oxadiazine, 1,2,4-Triazine and Pyrazole Derivatives with Antitumor Activities~!2010-02-19~!2010-06-08~!2010-08-27~!","authors":"R. Mohareb, R. Ibrahim, H. Moustafa","doi":"10.2174/1874095201004010008","DOIUrl":"https://doi.org/10.2174/1874095201004010008","url":null,"abstract":"","PeriodicalId":23020,"journal":{"name":"The Open Organic Chemistry Journal","volume":"1 1","pages":"8-14"},"PeriodicalIF":0.0,"publicationDate":"2010-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90660935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-05-20DOI: 10.2174/1874095201004010001
A. Bouraiou, A. Debache, S. Rhouati, A. Belfaitah, N. Benali-cherif, B. Carboni
N-Metallated azomethine ylide generated from methyl (E)-N-benzylideneglycinate, LiBr and triethylamine un- derwent cycloaddition to quinolyl , -unsaturated ketones with excellent diastereoselectivity to afford new functionalised 3-pyrrolidinylquinoline derivatives.
{"title":"Synthesis of Some New 3-Pyrrolidinylquinoline Derivatives via 1,3-Dipolar Cycloaddition of Stabilized Azomethine Ylides to Quinolinyl α , β - Unsaturated Ketones","authors":"A. Bouraiou, A. Debache, S. Rhouati, A. Belfaitah, N. Benali-cherif, B. Carboni","doi":"10.2174/1874095201004010001","DOIUrl":"https://doi.org/10.2174/1874095201004010001","url":null,"abstract":"N-Metallated azomethine ylide generated from methyl (E)-N-benzylideneglycinate, LiBr and triethylamine un- derwent cycloaddition to quinolyl , -unsaturated ketones with excellent diastereoselectivity to afford new functionalised 3-pyrrolidinylquinoline derivatives.","PeriodicalId":23020,"journal":{"name":"The Open Organic Chemistry Journal","volume":"30 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2010-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90926092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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