{"title":"Preparation of(NiCo)2 P/NF Self-supporting Electrode and Its Electrocatalytic Water Splitting","authors":"王 莎莎","doi":"10.3724/SP.J.7101438852","DOIUrl":"https://doi.org/10.3724/SP.J.7101438852","url":null,"abstract":"","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":"8 1","pages":"81-86"},"PeriodicalIF":5.062,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75677590","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}
{"title":"Effects of Different Linear Diamines on the Performance of Photocatalysts for Hydrogen Production of Sensitized Graphene","authors":"吕 功煊, 王 玉营, 张 旭强, 陈 建彪","doi":"10.3724/SP.J.7101438843","DOIUrl":"https://doi.org/10.3724/SP.J.7101438843","url":null,"abstract":"","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":"73 1","pages":"1-7"},"PeriodicalIF":5.062,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76452830","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}
{"title":"In Situ Synthesis of Ru Doped Hollow BiOBr Microsphere as an Efficient Photocatalyst for Photocatalytic CO2 Reduction and Organic Pollutant Degradation","authors":"迪 丽努尔·塔力甫, 阿 布力克木·阿布力孜, 张 俊杰, 亚 力昆江·吐尔逊","doi":"10.3724/SP.J.7101438844","DOIUrl":"https://doi.org/10.3724/SP.J.7101438844","url":null,"abstract":"","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":"9 1","pages":"8-18"},"PeriodicalIF":5.062,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77891399","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}
{"title":"The Research of CO Monoxide in Different Atmosphere on Au/Cu/FLA Catalysts at Low Temperature","authors":"孙 立波, 苏 慧娟, 郑 玉华, 祁 彩霞","doi":"10.3724/SP.J.7101438850","DOIUrl":"https://doi.org/10.3724/SP.J.7101438850","url":null,"abstract":"","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":"39 1","pages":"65-71"},"PeriodicalIF":5.062,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80612529","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}
{"title":"Gas-Phase Catalytic Isomerization of Tran-Chlorochloroolefin to Cis-Chlorochloroolefin and Its Potential Mechanism","authors":"吴 明亮","doi":"10.3724/SP.J.7101438846","DOIUrl":"https://doi.org/10.3724/SP.J.7101438846","url":null,"abstract":"","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":"52 1","pages":"28-35"},"PeriodicalIF":5.062,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89087235","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 : 2019-12-15DOI: 10.1097/QAI.0000000000002187
Tess OʼMeara, Yong Kong, Jennifer Chiarella, Richard W Price, Rabib Chaudhury, Xinran Liu, Serena Spudich, Kevin Robertson, Brinda Emu, Lingeng Lu
Background: Neurocognitive dysfunction remains prevalent among people living with HIV (PLWH), even after viral suppression on combination antiretroviral therapy (cART). We investigated associations between neuropsychological performance (NP) and patterns of circulating exosomal microRNA (exo-miRNA) expression in PLWH on cART.
Setting: A cross-sectional examination of plasma exo-miRNA among PLWH on cART with systemic viral suppression and volunteers without HIV infection.
Methods: Thirty-one PLWH who started cART during early infection (n = 19) or chronic infection (n = 12) participated in phlebotomy and an 11-test neuropsychological battery after >1 year on treatment. NP higher- or lower-performing participants were categorized based on normalized neuropsychological scores. Total RNA was extracted from purified exosomes of 31 PLWH and 5 volunteers without HIV and subject to small RNA sequencing. Differential expression of exo-miRNAs was examined and biological functions were predicted.
Results: Eleven exo-miRNAs were up-regulated in NP lower-performing (n = 18) relative to higher-performing PLWH (n = 13). A high proportion of the differentiating exo-miRNA target the axon guidance KEGG pathway and neurotrophin tyrosine receptor kinase signaling Gene Ontology pathway. Differential expression analysis of exo-miRNAs between NP lower- (n = 7) and higher-performing (n = 12) PLWH within the early infection group alone confirmed largely consistent findings.
Conclusions: Plasma exo-miRNA content differed between NP higher- and lower-performing PLWH. Several differentially expressed exo-miRNAs were predicted to be involved in inflammation and neurodegeneration pathways. Exo-miRNA in plasma may indicate cross-talk between the circulation and central nervous system and thus may be clinically relevant for neurocognitive dysfunction in PLWH.
{"title":"Exosomal MicroRNAs Associate With Neuropsychological Performance in Individuals With HIV Infection on Antiretroviral Therapy.","authors":"Tess OʼMeara, Yong Kong, Jennifer Chiarella, Richard W Price, Rabib Chaudhury, Xinran Liu, Serena Spudich, Kevin Robertson, Brinda Emu, Lingeng Lu","doi":"10.1097/QAI.0000000000002187","DOIUrl":"10.1097/QAI.0000000000002187","url":null,"abstract":"<p><strong>Background: </strong>Neurocognitive dysfunction remains prevalent among people living with HIV (PLWH), even after viral suppression on combination antiretroviral therapy (cART). We investigated associations between neuropsychological performance (NP) and patterns of circulating exosomal microRNA (exo-miRNA) expression in PLWH on cART.</p><p><strong>Setting: </strong>A cross-sectional examination of plasma exo-miRNA among PLWH on cART with systemic viral suppression and volunteers without HIV infection.</p><p><strong>Methods: </strong>Thirty-one PLWH who started cART during early infection (n = 19) or chronic infection (n = 12) participated in phlebotomy and an 11-test neuropsychological battery after >1 year on treatment. NP higher- or lower-performing participants were categorized based on normalized neuropsychological scores. Total RNA was extracted from purified exosomes of 31 PLWH and 5 volunteers without HIV and subject to small RNA sequencing. Differential expression of exo-miRNAs was examined and biological functions were predicted.</p><p><strong>Results: </strong>Eleven exo-miRNAs were up-regulated in NP lower-performing (n = 18) relative to higher-performing PLWH (n = 13). A high proportion of the differentiating exo-miRNA target the axon guidance KEGG pathway and neurotrophin tyrosine receptor kinase signaling Gene Ontology pathway. Differential expression analysis of exo-miRNAs between NP lower- (n = 7) and higher-performing (n = 12) PLWH within the early infection group alone confirmed largely consistent findings.</p><p><strong>Conclusions: </strong>Plasma exo-miRNA content differed between NP higher- and lower-performing PLWH. Several differentially expressed exo-miRNAs were predicted to be involved in inflammation and neurodegeneration pathways. Exo-miRNA in plasma may indicate cross-talk between the circulation and central nervous system and thus may be clinically relevant for neurocognitive dysfunction in PLWH.</p>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":"371 ","pages":"514-522"},"PeriodicalIF":2.9,"publicationDate":"2019-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6857839/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72437064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-16DOI: 10.1128/mSphere.00487-19
Rebekah B Guevara, Barbara A Fox, Alejandra Falla, David J Bzik
Little is known regarding how the chronic Toxoplasma gondii cyst develops. Here, we investigated intravacuolar-network-associated dense granule (GRA) proteins GRA1, GRA2, GRA4, GRA6, GRA9, and GRA12 during cyst development in vitro after differentiation of the tachyzoite-stage parasitophorous vacuole. By day 1 postdifferentiation, GRA1, GRA4, GRA6, GRA9, and GRA12 colocalized with Dolichos biflorus agglutinin stain at the cyst periphery. In contrast, GRA2 remained in the cyst matrix. By day 2 postdifferentiation, coinciding with localization of GRA2 to the cyst periphery, GRA1, GRA4, GRA6, and GRA9 established a continuous matrix pattern in the cyst. In contrast, GRA2 and GRA12 were colocalized in prominent cyst matrix puncta throughout cyst development. While GRA2, GRA6, and GRA12 localized in outer and inner layers of the cyst wall, GRA1, GRA4, and GRA9 localized predominantly in the inner layers of the cyst wall. GRA2 and GRA12 were colocalized in the cyst wall by day 7 postdifferentiation. However, by day 10 postdifferentiation, GRA12 was relocalized from the cyst wall to puncta in the cyst matrix. Differentiation of Δgra2 parasites revealed a defect in the ability to establish a normal cyst matrix. In addition, the deletion of any intravacuolar-network-associated GRA protein, except GRA1, reduced the rate of accumulation of cyst wall proteins at the cyst periphery relative to the cyst interior. Our findings reveal dynamic patterns of GRA protein localization during cyst development and suggest that intravacuolar-network-associated GRA proteins regulate the formation and maturation of the cyst matrix and cyst wall structures.IMPORTANCEToxoplasma gondii establishes chronic infection in humans by forming thick-walled cysts that persist in the brain. If host immunity wanes, cysts reactivate to cause severe, and often lethal, toxoplasmic encephalitis. There is no available therapy to eliminate cysts or to prevent their reactivation. Moreover, how the vital and characteristic cyst matrix and cyst wall structures develop is poorly understood. Here, we visualized and tracked the localization of Toxoplasma intravacuolar-network-associated dense granule (GRA) proteins during cyst development in vitro Intravacuolar-network GRAs were present within the cyst matrix and at the cyst wall in developing cysts, and genetic deletion of intravacuolar-network-associated GRAs reduced the rate of accumulation of cyst wall material at the cyst periphery. Our results show that intravacuolar-network-associated GRAs, particularly GRA2 and GRA12, play dynamic and essential roles in the development and maturation of the cyst matrix and the cyst wall structures.
{"title":"Toxoplasma gondii Intravacuolar-Network-Associated Dense Granule Proteins Regulate Maturation of the Cyst Matrix and Cyst Wall.","authors":"Rebekah B Guevara, Barbara A Fox, Alejandra Falla, David J Bzik","doi":"10.1128/mSphere.00487-19","DOIUrl":"10.1128/mSphere.00487-19","url":null,"abstract":"<p><p>Little is known regarding how the chronic <i>Toxoplasma gondii</i> cyst develops. Here, we investigated intravacuolar-network-associated dense granule (GRA) proteins GRA1, GRA2, GRA4, GRA6, GRA9, and GRA12 during cyst development <i>in vitro</i> after differentiation of the tachyzoite-stage parasitophorous vacuole. By day 1 postdifferentiation, GRA1, GRA4, GRA6, GRA9, and GRA12 colocalized with <i>Dolichos biflorus</i> agglutinin stain at the cyst periphery. In contrast, GRA2 remained in the cyst matrix. By day 2 postdifferentiation, coinciding with localization of GRA2 to the cyst periphery, GRA1, GRA4, GRA6, and GRA9 established a continuous matrix pattern in the cyst. In contrast, GRA2 and GRA12 were colocalized in prominent cyst matrix puncta throughout cyst development. While GRA2, GRA6, and GRA12 localized in outer and inner layers of the cyst wall, GRA1, GRA4, and GRA9 localized predominantly in the inner layers of the cyst wall. GRA2 and GRA12 were colocalized in the cyst wall by day 7 postdifferentiation. However, by day 10 postdifferentiation, GRA12 was relocalized from the cyst wall to puncta in the cyst matrix. Differentiation of Δ<i>gra2</i> parasites revealed a defect in the ability to establish a normal cyst matrix. In addition, the deletion of any intravacuolar-network-associated GRA protein, except GRA1, reduced the rate of accumulation of cyst wall proteins at the cyst periphery relative to the cyst interior. Our findings reveal dynamic patterns of GRA protein localization during cyst development and suggest that intravacuolar-network-associated GRA proteins regulate the formation and maturation of the cyst matrix and cyst wall structures.<b>IMPORTANCE</b><i>Toxoplasma gondii</i> establishes chronic infection in humans by forming thick-walled cysts that persist in the brain. If host immunity wanes, cysts reactivate to cause severe, and often lethal, toxoplasmic encephalitis. There is no available therapy to eliminate cysts or to prevent their reactivation. Moreover, how the vital and characteristic cyst matrix and cyst wall structures develop is poorly understood. Here, we visualized and tracked the localization of <i>Toxoplasma</i> intravacuolar-network-associated dense granule (GRA) proteins during cyst development <i>in vitro</i> Intravacuolar-network GRAs were present within the cyst matrix and at the cyst wall in developing cysts, and genetic deletion of intravacuolar-network-associated GRAs reduced the rate of accumulation of cyst wall material at the cyst periphery. Our results show that intravacuolar-network-associated GRAs, particularly GRA2 and GRA12, play dynamic and essential roles in the development and maturation of the cyst matrix and the cyst wall structures.</p>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":"282 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6796980/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41280973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-01-01DOI: 10.1016/j.molcata.2016.08.005
Natalia L. Parada Hernandez , Anderson J. Bonon , Juliana O. Bahú , Maria Ingrid R. Barbosa , Maria Regina Wolf Maciel , Rubens Maciel Filho
In order to obtain monomers from vegetable source, the castor oil epoxidation process was investigated. The catalytic system used in this work, H2O2/alumina/ethyl acetate, can be considered as a green system, free of heavy metals and toxic solvents. These characteristics make the system appropriate for the purpose of this study since they increase the probabilities of obtaining a biomaterial with the desired specifications regarding toxicity. Reaction conditions of castor oil epoxidation were optimized using methyl ricinoleate as a model compound. In order to identify the operating region, it was developed an experimental design 23 with 17 assays (6 axial points and central point in triplicate) in which, methyl ricinoleate, hydrogen peroxide and catalyst initial quantities in the reaction mixture were the studied variables. The system showed great efficiency with 100% of selectivity in the methyl ricinoleate epoxide production. In optimized conditions, it showed conversion of 99% in 6 h. It was obtained a conversion of 94%, an epoxidation percentage of 84 and a selectivity of 89% toward the epoxides for the castor oil epoxidation. These results show the efficacy of the catalytic system used in this work. Epoxidized castor oil structure was confirmed by FTIR, Raman and 1H NMR techniques.
{"title":"Epoxy monomers obtained from castor oil using a toxicity-free catalytic system","authors":"Natalia L. Parada Hernandez , Anderson J. Bonon , Juliana O. Bahú , Maria Ingrid R. Barbosa , Maria Regina Wolf Maciel , Rubens Maciel Filho","doi":"10.1016/j.molcata.2016.08.005","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.08.005","url":null,"abstract":"<div><p>In order to obtain monomers from vegetable source, the castor oil epoxidation process was investigated. The catalytic system used in this work, H<sub>2</sub>O<sub>2</sub>/alumina/ethyl acetate, can be considered as a green system, free of heavy metals and toxic solvents. These characteristics make the system appropriate for the purpose of this study since they increase the probabilities of obtaining a biomaterial with the desired specifications regarding toxicity. Reaction conditions of castor oil epoxidation were optimized using methyl ricinoleate as a model compound. In order to identify the operating region, it was developed an experimental design 2<sup>3</sup> with 17 assays (6 axial points and central point in triplicate) in which, methyl ricinoleate, hydrogen peroxide and catalyst initial quantities in the reaction mixture were the studied variables. The system showed great efficiency with 100% of selectivity in the methyl ricinoleate epoxide production. In optimized conditions, it showed conversion of 99% in 6<!--> <!-->h. It was obtained a conversion of 94%, an epoxidation percentage of 84 and a selectivity of 89% toward the epoxides for the castor oil epoxidation. These results show the efficacy of the catalytic system used in this work. Epoxidized castor oil structure was confirmed by FTIR, Raman and <sup>1</sup>H NMR techniques.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":"426 ","pages":"Pages 550-556"},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.08.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2660118","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 : 2017-01-01DOI: 10.1016/j.molcata.2016.11.006
Francesco Iannone , Michele Casiello , Antonio Monopoli , Pietro Cotugno , Maria Chiara Sportelli , Rosaria Anna Picca , Nicola Cioffi , Maria M. Dell’Anna , Angelo Nacci
A useful protocol for waste bis-phenol A-polycarbonates (BPA-PC) chemical recycling is proposed based on a bifunctional acid/basic catalyst composed by nanostructured zinc oxide and tetrabutylammonium chloride (ZnO-NPs/NBu4Cl) in quality of Lewis acid and base, respectively. Retro-polymerization reaction proved to be of general application for several nucleophiles, including water, alcohols, amines, polyols, aminols and polyamines, leading to the complete recovery of BPA monomer and enabling the PC polymer to function as a green carbonylating agent (green phosgene alternative) for preparing carbonates, urethanes and ureas. A complete depolymerization can be obtained in seven hours at 100 °C and ZnO nanocatalyst can be recycled several times without sensible loss of activity. Remarkably, when polycarbonate is reacted with glycerol, it is possible to realize in a single process the conversion of two industrial wastes (BPA-PC and glycerol) into two valuable chemicals like BPA monomer and glycerol carbonate (the latter being a useful industrial solvent and fuel additive).
{"title":"Ionic liquids/ZnO nanoparticles as recyclable catalyst for polycarbonate depolymerization","authors":"Francesco Iannone , Michele Casiello , Antonio Monopoli , Pietro Cotugno , Maria Chiara Sportelli , Rosaria Anna Picca , Nicola Cioffi , Maria M. Dell’Anna , Angelo Nacci","doi":"10.1016/j.molcata.2016.11.006","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.11.006","url":null,"abstract":"<div><p>A useful protocol for waste bis-phenol A-polycarbonates (BPA-PC) chemical recycling is proposed based on a bifunctional acid/basic catalyst composed by nanostructured zinc oxide and tetrabutylammonium chloride (ZnO-NPs/NBu<sub>4</sub>Cl) in quality of Lewis acid and base, respectively. Retro-polymerization reaction proved to be of general application for several nucleophiles, including water, alcohols, amines, polyols, aminols and polyamines, leading to the complete recovery of BPA monomer and enabling the PC polymer to function as a green carbonylating agent (green phosgene alternative) for preparing carbonates, urethanes and ureas. A complete depolymerization can be obtained in seven hours at 100<!--> <!-->°C and ZnO nanocatalyst can be recycled several times without sensible loss of activity. Remarkably, when polycarbonate is reacted with glycerol, it is possible to realize in a single process the conversion of two industrial wastes (BPA-PC and glycerol) into two valuable chemicals like BPA monomer and glycerol carbonate (the latter being a useful industrial solvent and fuel additive).</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":"426 ","pages":"Pages 107-116"},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.11.006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2660121","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 : 2017-01-01DOI: 10.1016/j.molcata.2016.10.027
Yurii A. Borisov, Irena S. Akhrem
The DFT B3LYP/6-31G* calculations were carried out for the reactions of C6H6 and Ad3C6H3 (Ad = 1,3,5-adamantyl) with superelectrophile CBr3+ as a model of superelectrophilic catalyst CBr3+ Al2Br7−. The reaction of C6H6 with CBr3+ proceeds via the classical scheme of electrophilic reactions of aromatic C − H bond to form initially the barrier-free σ-complex C6H6CBr3+. This mechanism was confirmed by the aug-cc-pVDZ basis set calculations. The reaction of Ad3C6H3 with CBr3+ occurs via a quite novel mechanism involving aryl cation formation followed by hydride abstraction of the Ar+ from the 2-Ad group and the rearrangement of the 2-Ad+ cation into the 4-phenyl-4-protoadamantyl cation. The hydride transfer from both arenes was shown to be more favorable than H radical transfer by more than 40 and 55 kcal mol−1 in the case of C6H6 and Ad3C6H3, respectively.
以超亲电催化剂CBr3+ Al2Br7−为模型，对C6H6和Ad3C6H3 (Ad = 1,3,5-adamantyl)与超亲电试剂CBr3+的反应进行了DFT B3LYP/6-31G*计算。C6H6与CBr3+的反应遵循芳香族C−H键亲电反应的经典模式，初步形成无障碍的σ-配合物C6H6CBr3+。该机理得到了aug-cc-pVDZ基集计算的证实。Ad3C6H3与CBr3+的反应发生在芳基阳离子形成后，2-Ad基上的Ar+被氢化物萃取，2-Ad+阳离子重排为4-苯基-4-原金刚烷基阳离子。结果表明，C6H6和Ad3C6H3的氢化物转移比H自由基转移更有利，转移量分别大于40和55 kcal mol−1。
{"title":"DFT mechanistic study of reactions of С6H6 and 1,3,5-Ad3C6H3 with CBr3. The first example of hydride transfer from aromatic CH bond to electrophile","authors":"Yurii A. Borisov, Irena S. Akhrem","doi":"10.1016/j.molcata.2016.10.027","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.10.027","url":null,"abstract":"<div><p>The DFT B3LYP/6-31G* calculations were carried out for the reactions of C<sub>6</sub>H<sub>6</sub> and Ad<sub>3</sub>C<sub>6</sub>H<sub>3</sub> (Ad<!--> <!-->=<!--> <!-->1,3,5-adamantyl) with superelectrophile CBr<sub>3</sub><sup>+</sup> as a model of superelectrophilic catalyst CBr<sub>3</sub><sup>+</sup> Al<sub>2</sub>Br<sub>7</sub><sup>−</sup>. The reaction of C<sub>6</sub>H<sub>6</sub> with CBr<sub>3</sub><sup>+</sup> proceeds <em>via</em> the classical scheme of electrophilic reactions of aromatic C<!--> <!-->−<!--> <!-->H bond to form initially the barrier-free σ-complex C<sub>6</sub>H<sub>6</sub>CBr<sub>3</sub><sup>+</sup>. This mechanism was confirmed by the aug-cc-pVDZ basis set calculations. The reaction of Ad<sub>3</sub>C<sub>6</sub>H<sub>3</sub> with CBr<sub>3</sub><sup>+</sup> occurs <em>via</em> a quite novel mechanism involving aryl cation formation followed by hydride abstraction of the Ar<sup>+</sup> from the 2-Ad group and the rearrangement of the 2-Ad<sup>+</sup> cation into the 4-phenyl-4-protoadamantyl cation. The hydride transfer from both arenes was shown to be more favorable than H radical transfer by more than 40 and 55<!--> <!-->kcal<!--> <!-->mol<sup>−1</sup> in the case of C<sub>6</sub>H<sub>6</sub> and Ad<sub>3</sub>C<sub>6</sub>H<sub>3</sub>, respectively.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":"426 ","pages":"Pages 610-617"},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.10.027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2798707","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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