Pub Date : 2017-04-05DOI: 10.1080/10426507.2017.1315418
J. Khanjani, M. Zohuriaan‐Mehr, S. Pazokifard
GRAPHICAL ABSTRACT ABSTRACT Octamethylcyclotetrasiloxane (D4) was polymerized in a microemulsion system using novel formulations, in which acrylamide was involved as a co-emulsifier. Dodecylbenzene sulfonic acid was used as both a cationic initiator and emulsifier. The effect of emulsifiers, D4, feeding rate and temperature on conversion, polymerization rate (Rp), latex stability and particle sizes were investigated. A conventional (macroemulsion) system was also studied comparatively. Rp in the microemulsion was quickly increased to a maximum of 0.108 mol L−1s−1 at ∼30 min corresponding to a conversion of ∼38%, and then decreased with reaction progression over a period of 30–110 min. In the macroemulsion system, however, a constant rate was observed between conversion 30% and 50%, and its optimal sample contained an average particle diameter of 88 nm while that from microemulsion had smaller particles with diameter of 19 nm. Activation energies were also estimated to be 31.5 and 41.1 kJ/mol for the microemulsion and macroemulsion systems, respectively.
{"title":"Microemulsion and macroemulsion polymerization of octamethylcyclotetrasiloxane: A comparative study","authors":"J. Khanjani, M. Zohuriaan‐Mehr, S. Pazokifard","doi":"10.1080/10426507.2017.1315418","DOIUrl":"https://doi.org/10.1080/10426507.2017.1315418","url":null,"abstract":"GRAPHICAL ABSTRACT ABSTRACT Octamethylcyclotetrasiloxane (D4) was polymerized in a microemulsion system using novel formulations, in which acrylamide was involved as a co-emulsifier. Dodecylbenzene sulfonic acid was used as both a cationic initiator and emulsifier. The effect of emulsifiers, D4, feeding rate and temperature on conversion, polymerization rate (Rp), latex stability and particle sizes were investigated. A conventional (macroemulsion) system was also studied comparatively. Rp in the microemulsion was quickly increased to a maximum of 0.108 mol L−1s−1 at ∼30 min corresponding to a conversion of ∼38%, and then decreased with reaction progression over a period of 30–110 min. In the macroemulsion system, however, a constant rate was observed between conversion 30% and 50%, and its optimal sample contained an average particle diameter of 88 nm while that from microemulsion had smaller particles with diameter of 19 nm. Activation energies were also estimated to be 31.5 and 41.1 kJ/mol for the microemulsion and macroemulsion systems, respectively.","PeriodicalId":20043,"journal":{"name":"Phosphorus Sulfur and Silicon and The Related Elements","volume":"259 1","pages":"967 - 976"},"PeriodicalIF":0.0,"publicationDate":"2017-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76629349","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}
GRAPHICAL ABSTRACT ABSTRACT An improved synthesis of N-sulfonylformamidine derivatives has been developed involving direct condensation of various sulfonamides and formamides in the presence of thionyl chloride using chloroform as solvent. Detailed synthetic studies indicate that this procedure gives the desired products in high yields under mild conditions.
{"title":"Improved synthesis of N-sulfonylformamidine derivatives promoted by thionyl chloride","authors":"Ruzeahong Hudabaierdi, Abudureheman Wusiman, Ayinigeer Mulati","doi":"10.1080/10426507.2017.1284843","DOIUrl":"https://doi.org/10.1080/10426507.2017.1284843","url":null,"abstract":"GRAPHICAL ABSTRACT ABSTRACT An improved synthesis of N-sulfonylformamidine derivatives has been developed involving direct condensation of various sulfonamides and formamides in the presence of thionyl chloride using chloroform as solvent. Detailed synthetic studies indicate that this procedure gives the desired products in high yields under mild conditions.","PeriodicalId":20043,"journal":{"name":"Phosphorus Sulfur and Silicon and The Related Elements","volume":"353 1","pages":"485 - 489"},"PeriodicalIF":0.0,"publicationDate":"2017-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77321162","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 : 2017-03-03DOI: 10.1080/10426507.2017.1300034
G. Hägele
Phosphoros–the Morningstar, what a wonderful world came down to us through the millennia–let us keep and protect it! And Harry Hudson was able to wander between the worlds of arts and science as well. His advice in English history and literature was well accepted, like his profound knowledge in chemistry. We teamed up as partners in a group of chemists named EUROPHOS and combined our labs in London and in Düsseldorf with syntheses, analytics, structures, NMR spectroscopy and biological aspects. We enjoyed mutual visits, supported by binational funds, and looked into α-aminophosphonic acids, α-aminophosphinic acids and corresponding esters, generally abbreviated as NHR1-CHR2-P(O)(R3)OR4. Selected results were published in a review, edited by V. Khukar and H. R. Hudson1 and in several publications.2a–j Molecular modelling, ring current calculations, and NMR were combined to understand complex 1H NMR spectra of NHPh-CHPh-P(O(OEt)2 and related structures.3 Compounds with sterically demanding substituents NH(CHPh2)-CHR-P(O(OEt)2 (R2 = Ph, Naphthyl, Anthranyl, Pyrenyl) were synthesized.4a–b Our particular interests were drawn toward the sterically overcrowded α-N-(diphenylmethyl)amino-α-(1-pyrenyl)methanephosphonic acid diethylester NH(CHPh2)-CH (Pyr)-P(O(OEt)2 which gave rise to a 1H NMR spectrum5 (Figure 1) involving a total of 29 spins (Scheme 1):
磷——晨星，千百年来给我们带来了一个多么美好的世界——让我们保持和保护它!哈里·哈德森也能够在艺术和科学的世界之间徘徊。他在英国历史和文学方面的建议很受欢迎，就像他在化学方面的渊博知识一样。我们与一组名为EUROPHOS的化学家合作，将我们在伦敦和杜塞尔多夫的实验室与合成、分析、结构、核磁共振光谱和生物学方面结合起来。我们在两国基金的支持下进行了互访，研究了α-氨基膦酸、α-氨基膦酸及其相应的酯类，一般简称为NHR1-CHR2-P(O)(R3)OR4。选定的结果发表在由V. Khukar和H. R. hudson编辑的一篇综述和几份出版物上。2 .结合分子模拟、环电流计算和核磁共振，了解NHPh-CHPh-P(O(OEt)2及其相关结构的复杂1H NMR谱合成了具有空间要求取代基nhh (CHPh2)- chrp (O(OEt)2 (R2 = Ph)、萘基、蒽基、芘基的化合物。我们特别感兴趣的是空间过度饱和的α-N-(二苯基甲基)氨基-α-(1-芘基)甲膦酸二乙基酯NH(CHPh2)- ch (Pyr)- p (O(OEt)2，它产生了一个共涉及29个自旋的1H NMR谱5(图1)(方案1):
{"title":"Some introductory remarks to “In memoriam of Prof. Harry R. Hudson”","authors":"G. Hägele","doi":"10.1080/10426507.2017.1300034","DOIUrl":"https://doi.org/10.1080/10426507.2017.1300034","url":null,"abstract":"Phosphoros–the Morningstar, what a wonderful world came down to us through the millennia–let us keep and protect it! And Harry Hudson was able to wander between the worlds of arts and science as well. His advice in English history and literature was well accepted, like his profound knowledge in chemistry. We teamed up as partners in a group of chemists named EUROPHOS and combined our labs in London and in Düsseldorf with syntheses, analytics, structures, NMR spectroscopy and biological aspects. We enjoyed mutual visits, supported by binational funds, and looked into α-aminophosphonic acids, α-aminophosphinic acids and corresponding esters, generally abbreviated as NHR1-CHR2-P(O)(R3)OR4. Selected results were published in a review, edited by V. Khukar and H. R. Hudson1 and in several publications.2a–j Molecular modelling, ring current calculations, and NMR were combined to understand complex 1H NMR spectra of NHPh-CHPh-P(O(OEt)2 and related structures.3 Compounds with sterically demanding substituents NH(CHPh2)-CHR-P(O(OEt)2 (R2 = Ph, Naphthyl, Anthranyl, Pyrenyl) were synthesized.4a–b Our particular interests were drawn toward the sterically overcrowded α-N-(diphenylmethyl)amino-α-(1-pyrenyl)methanephosphonic acid diethylester NH(CHPh2)-CH (Pyr)-P(O(OEt)2 which gave rise to a 1H NMR spectrum5 (Figure 1) involving a total of 29 spins (Scheme 1):","PeriodicalId":20043,"journal":{"name":"Phosphorus Sulfur and Silicon and The Related Elements","volume":"48 5 1","pages":"578 - 580"},"PeriodicalIF":0.0,"publicationDate":"2017-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82764680","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 : 2017-03-03DOI: 10.1080/10426507.2017.1302448
F. Ghodsi, S. Habibi‐Khorassani, M. Shahraki
ABSTRACT The kinetics and mechanism of the reaction between dimethyl acetylendicarboxylate (DMAD) and Meldrum's acid (MA) in the presence of triphenylarsine (TPA) as a catalyst were investigated in a methanol environment by the UV/vis spectrophotometry technique. In this work, the reaction followed second- order kinetics and the first and second steps of the reaction mechanism were recognized as the fast and rate-determining step (RDS), respectively. A significant point in this reaction “in comparison with previous work” is related to the change in behavior of the kinetics and reaction mechanism in the presence of triphenylarsine (TPA). Activation energy and parameters (Ea, ΔH‡, ΔS‡, and ΔG‡) were determined for the reaction and a comparison between ΔH‡ and TΔS‡ values showed that the reaction is entropy-controlled. High values of the activation Gibbs free energy indicated that the reaction was chemically controlled. Also, the large negative value of ΔS‡ implied an associative mechanism. GRAPHICAL ABSTRACT
{"title":"Triphenylarsine as an effective catalyst in a mechanistic investigation of trans- 1, 2-di (methoxycarbonyl)-6, 6-dimethyl-5, 7-dioxaspiro [2, 5] octane-4, 8-dione formation","authors":"F. Ghodsi, S. Habibi‐Khorassani, M. Shahraki","doi":"10.1080/10426507.2017.1302448","DOIUrl":"https://doi.org/10.1080/10426507.2017.1302448","url":null,"abstract":"ABSTRACT The kinetics and mechanism of the reaction between dimethyl acetylendicarboxylate (DMAD) and Meldrum's acid (MA) in the presence of triphenylarsine (TPA) as a catalyst were investigated in a methanol environment by the UV/vis spectrophotometry technique. In this work, the reaction followed second- order kinetics and the first and second steps of the reaction mechanism were recognized as the fast and rate-determining step (RDS), respectively. A significant point in this reaction “in comparison with previous work” is related to the change in behavior of the kinetics and reaction mechanism in the presence of triphenylarsine (TPA). Activation energy and parameters (Ea, ΔH‡, ΔS‡, and ΔG‡) were determined for the reaction and a comparison between ΔH‡ and TΔS‡ values showed that the reaction is entropy-controlled. High values of the activation Gibbs free energy indicated that the reaction was chemically controlled. Also, the large negative value of ΔS‡ implied an associative mechanism. GRAPHICAL ABSTRACT","PeriodicalId":20043,"journal":{"name":"Phosphorus Sulfur and Silicon and The Related Elements","volume":"Suppl 1","pages":"960 - 966"},"PeriodicalIF":0.0,"publicationDate":"2017-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90229647","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 : 2017-02-22DOI: 10.1080/10426507.2017.1296732
G. Keglevich
{"title":"Recalling my memories with Professor Harry R. Hudson","authors":"G. Keglevich","doi":"10.1080/10426507.2017.1296732","DOIUrl":"https://doi.org/10.1080/10426507.2017.1296732","url":null,"abstract":"","PeriodicalId":20043,"journal":{"name":"Phosphorus Sulfur and Silicon and The Related Elements","volume":"36 1","pages":"581 - 581"},"PeriodicalIF":0.0,"publicationDate":"2017-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73582100","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 : 2017-02-21DOI: 10.1080/10426507.2017.1295960
M. Taherzadeh, M. Pourayoubi, R. Afzali, M. Nečas
GRAPHICAL ABSTRACT ABSTRACT The hydrogen bond pattern of N-(4-methoxybenzoyl)-N′,N″-bis(4-methylbenzyl)-phosphoric triamide, C24H28N3O3P, (I), was investigated. In the crystal structure, the molecules are aggregated through NCP―H···O═P and NP―H···O═C hydrogen bonds in a one-dimensional arrangement parallel to the c axis (NCP is the nitrogen atom in the C(O)NHP(O) segment and NP stands for the two other nitrogen atoms bonded to the P atom). There is also a novel NP‒H···π hydrogen bond in the crystal which extends the aggregation of the molecules to a two-dimensional array parallel to the bc plane. A Cambridge Structural Database (CSD, version 5.37, Feb 2016) analysis shows that the N―H···π hydrogen bond was not observed in any of 156 [RC(O)NH]P(O)[NR1R2]2 (R1 ≠ H, R2 = H or ≠ H) phosphoric triamide structures reported so far. The theoretical calculations at the B3LYP/6-311G** level of theory (DFT, AIM, and NBO) were performed to evaluate the strengths of NCP―H···O═P, NP―H···O═C and NP―H···π hydrogen bonds, considering two-aggregate molecular assemblies containing these hydrogen bonds. The calculations on the title compound suggest that the intermolecular NCP―H···O═P hydrogen bond is stronger than NP―H···O═C and NP―H···π interactions. The hydrogen bond strength was investigated by NBO, topological analysis, geometry calculation, Hirshfeld surface analysis and experimental spectroscopic results, which are in agreement with each other.
{"title":"The first C(O)NHP(O)-based phosphoric triamide structure with an N‒H···π hydrogen bonding: A combination of X-ray crystallography and theoretical study to evaluate the strength of hydrogen bonds","authors":"M. Taherzadeh, M. Pourayoubi, R. Afzali, M. Nečas","doi":"10.1080/10426507.2017.1295960","DOIUrl":"https://doi.org/10.1080/10426507.2017.1295960","url":null,"abstract":"GRAPHICAL ABSTRACT ABSTRACT The hydrogen bond pattern of N-(4-methoxybenzoyl)-N′,N″-bis(4-methylbenzyl)-phosphoric triamide, C24H28N3O3P, (I), was investigated. In the crystal structure, the molecules are aggregated through NCP―H···O═P and NP―H···O═C hydrogen bonds in a one-dimensional arrangement parallel to the c axis (NCP is the nitrogen atom in the C(O)NHP(O) segment and NP stands for the two other nitrogen atoms bonded to the P atom). There is also a novel NP‒H···π hydrogen bond in the crystal which extends the aggregation of the molecules to a two-dimensional array parallel to the bc plane. A Cambridge Structural Database (CSD, version 5.37, Feb 2016) analysis shows that the N―H···π hydrogen bond was not observed in any of 156 [RC(O)NH]P(O)[NR1R2]2 (R1 ≠ H, R2 = H or ≠ H) phosphoric triamide structures reported so far. The theoretical calculations at the B3LYP/6-311G** level of theory (DFT, AIM, and NBO) were performed to evaluate the strengths of NCP―H···O═P, NP―H···O═C and NP―H···π hydrogen bonds, considering two-aggregate molecular assemblies containing these hydrogen bonds. The calculations on the title compound suggest that the intermolecular NCP―H···O═P hydrogen bond is stronger than NP―H···O═C and NP―H···π interactions. The hydrogen bond strength was investigated by NBO, topological analysis, geometry calculation, Hirshfeld surface analysis and experimental spectroscopic results, which are in agreement with each other.","PeriodicalId":20043,"journal":{"name":"Phosphorus Sulfur and Silicon and The Related Elements","volume":"202 1","pages":"936 - 944"},"PeriodicalIF":0.0,"publicationDate":"2017-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75678933","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 : 2017-02-21DOI: 10.1080/10426507.2017.1292274
F. Ghodsi, M. Shahraki, S. Habibi‐Khorassani, Maryam Shokoohian
GRAPHICAL ABSTRACT ABSTRACT Dynamic 1H NMR measurements have been experimentally performed in particular phosphorus ylides involving 2-mercaptobenzimidazole and 2-mercaptobenzoxazole for comparison around the C˭C double bond and two single bonds (C‒C and C‒N). Also, activation parameters including ΔG‡, ΔS‡ and ΔΗ‡ were calculated using the ab initio and DFT methods at the HF/6-31G (d,p) and B3LYP/6-31G(d,p) levels of theory for the rotational interchangeable process of the two Z and E isomers of the ylides in the presence of a solvent environment (CDCl3). The obtained results were consistent with the dynamic 1H NMR data. The rotational energy barrier around the carbon=carbon double bond in the ylide 4 derived from triphenylphosphine was 2 kcal⋅mol−1 higher in energy than the generated ylide 5 from triethylphosphite. In general, in both rotational Z and E isomers of ylide 5, the rotational energy barrier around the carbon–nitrogen single bond was higher for the carbon‒carbon single bond due to the inversion of a lone pair on nitrogen atom during a rotation. Although, the HF/6-31G(d,p) level was a desirable level for the rotation around the single bond, nevertheless, the B3LYP/6-31G(d,p) level was recognized as a suitable level for rotation around the double bond. Applying solvent media (chloroform) at the two levels of calculations increased consistency with the experimental results.
{"title":"The comparison of the dynamic 1H NMR measurements between two special ylides derived from triphenylphosphine and triethylphosphite: Experimental and theoretical calculations","authors":"F. Ghodsi, M. Shahraki, S. Habibi‐Khorassani, Maryam Shokoohian","doi":"10.1080/10426507.2017.1292274","DOIUrl":"https://doi.org/10.1080/10426507.2017.1292274","url":null,"abstract":"GRAPHICAL ABSTRACT ABSTRACT Dynamic 1H NMR measurements have been experimentally performed in particular phosphorus ylides involving 2-mercaptobenzimidazole and 2-mercaptobenzoxazole for comparison around the C˭C double bond and two single bonds (C‒C and C‒N). Also, activation parameters including ΔG‡, ΔS‡ and ΔΗ‡ were calculated using the ab initio and DFT methods at the HF/6-31G (d,p) and B3LYP/6-31G(d,p) levels of theory for the rotational interchangeable process of the two Z and E isomers of the ylides in the presence of a solvent environment (CDCl3). The obtained results were consistent with the dynamic 1H NMR data. The rotational energy barrier around the carbon=carbon double bond in the ylide 4 derived from triphenylphosphine was 2 kcal⋅mol−1 higher in energy than the generated ylide 5 from triethylphosphite. In general, in both rotational Z and E isomers of ylide 5, the rotational energy barrier around the carbon–nitrogen single bond was higher for the carbon‒carbon single bond due to the inversion of a lone pair on nitrogen atom during a rotation. Although, the HF/6-31G(d,p) level was a desirable level for the rotation around the single bond, nevertheless, the B3LYP/6-31G(d,p) level was recognized as a suitable level for rotation around the double bond. Applying solvent media (chloroform) at the two levels of calculations increased consistency with the experimental results.","PeriodicalId":20043,"journal":{"name":"Phosphorus Sulfur and Silicon and The Related Elements","volume":"94 1","pages":"929 - 935"},"PeriodicalIF":0.0,"publicationDate":"2017-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90723992","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 : 2017-02-21DOI: 10.1080/10426507.2017.1295961
H. Yarahmadi, M. Ghashang, Saeid Jabbar Zare, A. Khodaivandi
GRAPHICAL ABSTRACT ABSTRACT Uniform nanopowders of barium aluminate (BaAl2O4) can be synthesized by a facile solution reaction at room temperature using barium and aluminum salts and 2-aminoethanol as a precipitating agent. The as-prepared sample showed a good reactivity in the synthesis of benzo[b]thiophene, thieno[2,3-c]thiopyran and thieno[2,3-c]pyridine derivatives. Comparatively the method is efficient and eco-friendly, and finally, a range of compounds with variable functionalities in excellent yield can be achieved.
{"title":"Barium aluminate nano-powders efficient catalyst for the synthesis of novel benzo[b]thiophene, thieno[2,3-c]thiopyran and thieno[2,3-c]pyridine derivatives","authors":"H. Yarahmadi, M. Ghashang, Saeid Jabbar Zare, A. Khodaivandi","doi":"10.1080/10426507.2017.1295961","DOIUrl":"https://doi.org/10.1080/10426507.2017.1295961","url":null,"abstract":"GRAPHICAL ABSTRACT ABSTRACT Uniform nanopowders of barium aluminate (BaAl2O4) can be synthesized by a facile solution reaction at room temperature using barium and aluminum salts and 2-aminoethanol as a precipitating agent. The as-prepared sample showed a good reactivity in the synthesis of benzo[b]thiophene, thieno[2,3-c]thiopyran and thieno[2,3-c]pyridine derivatives. Comparatively the method is efficient and eco-friendly, and finally, a range of compounds with variable functionalities in excellent yield can be achieved.","PeriodicalId":20043,"journal":{"name":"Phosphorus Sulfur and Silicon and The Related Elements","volume":"15 1","pages":"945 - 949"},"PeriodicalIF":0.0,"publicationDate":"2017-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88363980","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 : 2017-02-17DOI: 10.1080/10426507.2017.1292273
J. Voss, D. Otzen, G. Adiwidjaja
GRAPHICAL ABSTRACT ABSTRACT Methyl 3,5-anhydro-3-thiopentofuranosides (“3,5-Thietanopentosides”) of the D-xylo, L-lyxo and 2-deoxy-D-threo series were oxidized to the corresponding S-oxides (sulfoxides) and/or S,S-dioxides (sulfones) by use of hydrogen peroxide or meta-chloroperbenzoic acid. The diastereoisomers resulting from the additional chiral sulfur center in the sulfoxides could be separated. Their configuration was assigned by NMR spectroscopy and in one case unequivocally corroborated by an X-ray structure analysis. The observed stereoselectivity of the oxidation can be attributed to the specific steric requirements in the different thietano sugars. X-Ray structural analyses of three crystalline sulfones were also performed. Attempts to generate carbanions of the sulfoxides and sulfones and to use these for reactions with electrophiles were not successful.
{"title":"3,5-Thietanopentofuranoside S-oxides and S,S-dioxides – preparation and structural characterization","authors":"J. Voss, D. Otzen, G. Adiwidjaja","doi":"10.1080/10426507.2017.1292273","DOIUrl":"https://doi.org/10.1080/10426507.2017.1292273","url":null,"abstract":"GRAPHICAL ABSTRACT ABSTRACT Methyl 3,5-anhydro-3-thiopentofuranosides (“3,5-Thietanopentosides”) of the D-xylo, L-lyxo and 2-deoxy-D-threo series were oxidized to the corresponding S-oxides (sulfoxides) and/or S,S-dioxides (sulfones) by use of hydrogen peroxide or meta-chloroperbenzoic acid. The diastereoisomers resulting from the additional chiral sulfur center in the sulfoxides could be separated. Their configuration was assigned by NMR spectroscopy and in one case unequivocally corroborated by an X-ray structure analysis. The observed stereoselectivity of the oxidation can be attributed to the specific steric requirements in the different thietano sugars. X-Ray structural analyses of three crystalline sulfones were also performed. Attempts to generate carbanions of the sulfoxides and sulfones and to use these for reactions with electrophiles were not successful.","PeriodicalId":20043,"journal":{"name":"Phosphorus Sulfur and Silicon and The Related Elements","volume":"26 1","pages":"919 - 928"},"PeriodicalIF":0.0,"publicationDate":"2017-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83398696","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 : 2017-02-17DOI: 10.1080/10426507.2017.1292272
Zhengbo Han, Wen-Yuan Wu, F. Chen, Xixia Guan, Xiao-Huan Fu, Peng Jiang, Rong Wan
GRAPHICAL ABSTRACT ABSTRACT On the basis of the commercial insecticide Fipronil, a series of novel arylpyrazole derivatives containing the cyhalothroyl thiourea moiety were designed and synthesized via the key intermediate 5-amino-3-cyano-1-(substituted phenyl) pyrazole. The structures of target compounds were characterized by 1H NMR, FT-IR, elemental analysis and single crystal X-ray diffraction analysis. Their insecticidal activities against Culex pipiens and Musca domestica were evaluated. The results of bioassays indicated that title compounds exhibited satisfactory insecticidal activities. Among those, Compound 7t ((E)-3-(2-chloro- 3, 3, 3-trifluoroprop-1-en-1-yl)-N-((3-cyano-1-(2, 6- dichloro-4-(trifluoromethyl) phenyl)-1H-pyrazol-5-yl) carbamothioyl)- 2, 2-dimethyl cyclopropane carboxamide) exhibited the best insecticidal activities because of its lowest KT50 values, which are superior to the commercial insecticide Dextral tetramethrin and similar to Prallethrin. The type and position of substituent on the benzene ring played important roles on the biological activities of target compounds.
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