Journal of Molecular Catalysis A: Chemical最新文献

{"title":"Cage-like metallasilsesquioxanes in catalysis: A review","authors":"Mikhail M. Levitsky ,&nbsp;Alexey I. Yalymov ,&nbsp;Alena N. Kulakova ,&nbsp;Аrtem А. Petrov ,&nbsp;Аlexey N. Bilyachenko","doi":"10.1016/j.molcata.2016.06.016","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.06.016","url":null,"abstract":"<div><p>The review describes catalytic properties of a unique class of metal complexes—polycyclic cage-like metallasilsesquioxanes. Article is composed in retrospective manner and reflects the progress of the investigations in the field: from classic applications to recently discovered perspectives of cage-like metallasilsesquioxanes in catalysis of oxidation of С–H compounds.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":null,"pages":null},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.06.016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2879559","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":"Mechanisms of alkane CH-activation: The 5/6 effect, single-factor compensation effect, strongest reactant and earliest transition state. A puzzle of Shilov reaction","authors":"Elisey S. Rudakov","doi":"10.1016/j.molcata.2016.07.034","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.07.034","url":null,"abstract":"<div><p>The results on the investigation of alkane activation kinetics and mechanisms in aqueous and acidic media, including theoretical and experimental approaches to the problem, proposed by the author are summarized. The new concepts are introduced: a “direct kinetic study of CH activation”, “visible and hidden reagent preactivation”, the “strongest reactant and earliest transition state” (ETS), the “5/6 effect” (the ratio of C<img>H bonds splitting constant rates in the <em>с</em>-C₅H₁₀/<em>с</em>-C₆H₁₂ couple), “single-factor compensation effect” (SCE), and a “refined compensation temperature”. The compensation effect (CE) exists in reality, but it is necessary to exclude the influence side factors, for example, to go from rate constants to the 5/6 effect to observe its purest form. The 5/6-CE combination as an example SCE is a new instrument for studying CH-activation mechanisms. Temperature dependences of (5/6) values for the reagents in aqueous solution (Pt^II, MnO₄⁻, HMnO₄, HOCl, HOONO, HVO₂ – Ru^IV, OH<img>, SO₄<img>⁻) and sulfuric acid (Pd^II, Hg^II, CrO₃, Mn^III, Co^III, NO₂⁺, OH⁺, 1-adamantyl cation, C₁₄H₁₁⁺, СН₂OH⁺, SO₃H<strong>⁺</strong>) are found. The only influencing factor on the (5/6) value is conformational strain difference in the C₅ and C₆ rings, which in a series of one-type reactions decreases with increasing the reagent activity. Four mechanisms are revealed: H-atom abstraction by anionic (<strong>I</strong>⁻), uncharged (<strong>I</strong>⁰) and cationic (<strong>I⁺</strong>) oxygen-centered “O-reactants”, and a bifunctional incorporation into C<img>H bond of electrophilic cation – base adduct (<strong>II⁺</strong>). Various SCE lines (the entropy change versus enthalpy changing) for these groups are found. They converge in a “SCE pole” (the first example of ETS). Features of these mechanisms, differences of Pt^II, Pd^II, Hg^II acidocomplexes as the reagents and a surprising similarity between the Shilov reactant Pt^IICl₃(H₂O) and OH radicals in the water are discussed. The probable general cause of CEs in various processes is compensation effects in thermodynamics of interparticle interactions.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":null,"pages":null},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.07.034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2879563","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":"Copper(II) arylhydrazone complexes as catalysts for CH activation in the Henry reaction in water","authors":"Zhen Ma ,&nbsp;Atash V. Gurbanov ,&nbsp;Abel M. Maharramov ,&nbsp;Firudin I. Guseinov ,&nbsp;Maximilian N. Kopylovich ,&nbsp;Fedor I. Zubkov ,&nbsp;Kamran T. Mahmudov ,&nbsp;Armando J.L. Pombeiro","doi":"10.1016/j.molcata.2016.05.030","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.05.030","url":null,"abstract":"<div><p>Three new water-soluble copper(II) complexes [Cu(HL)(H₂O){(CH₃)₂NCHO}] (<strong>1</strong>), [Cu(H₂L)₂(im)₄]·CH₃OH (<strong>2</strong>) and [Cu(HL)(CH₃OH)]₂(<em>μ</em>₂-py) (<strong>3</strong>) were synthesized from copper(II) nitrate and sodium (<em>Z</em>)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzene-sulfonate (NaH₂L), in the absence (for <strong>1</strong>) and presence of imidazole (im) (for <strong>2</strong>) or pyrazine (py) (for <strong>3</strong>), and fully characterized. The complexes <strong>1–3</strong> have been tested as stereoselective C<img>H activating catalysts for the model nitroaldol (Henry) condensation of nitroethane with various aldehydes in water. <strong>1</strong> was the most active catalyst affording 64−87% yields with <em>syn/anti</em> diasteroselectivities up to 77:23.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":null,"pages":null},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.05.030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2879565","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":"μ-Borole triple-decker complexes as catalysts for oxidative coupling of benzoic acid with alkynes. Structure of a hybrid rhodacyclopentadienyl/borole triple-decker complex","authors":"Dmitry A. Loginov,&nbsp;Dmitry V. Muratov,&nbsp;Yulia V. Nelyubina,&nbsp;Julia Laskova,&nbsp;Alexander R. Kudinov","doi":"10.1016/j.molcata.2016.07.004","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.07.004","url":null,"abstract":"<div><p>Reaction of dimethylamine adduct of 1-methyl-3-borolene with [(C₂H₄)₂RhCl]₂ gives the triple-decker complex (η-C₄H₄BMe)Rh(μ-η:η-C₄H₄BMe)Rh(η-C₄H₄BMe) (<strong>1a</strong>) in 62% yield and trace amount (&lt;1%) of the hybrid rhodacyclopentadienyl/borole triple-decker complex (η-C₄H₄BMe)Rh(μ-η:η-C₄H₄Rh{(μ-η:η-C₄H₄BMe)Rh(η-C₄H₄BMe)})Rh(η-C₄H₄BMe) (<strong>2</strong>). The structure of <strong>2</strong> was determined by X-ray diffraction. In the presence of Cu(OAc)₂, <strong>1a</strong> and (η-C₄H₄BPh)Rh(μ-η:η-C₄H₄BPh)Rh(η-C₄H₄BPh) (<strong>1b</strong>) catalyze the oxidative coupling of benzoic acid with diphenylacetylene selectively giving 1,2,3,4-tetraphenylnaphtalene in 50–90% yields. Analogous reactions of benzoic acid with 1-phenyl-1-butyne catalyzed by <strong>1a</strong> and [CpRhI₂]₂ regioselectively give 1,4-diethyl-2,3-diphenylnaphthalene. The related dicationic triple-decker complexes [(9-SMe₂-7,8-C₂B₉H₁₀)Rh(μ-η:η-C₄H₄BPh)Rh(9-SMe₂-7,8-C₂B₉H₁₀)]²⁺ (<strong>3</strong>) and [Cp*Rh(μ-η:η-C₄H₄BPh)IrCp*]²⁺ (<strong>4</strong>) were also tested as catalysts.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":null,"pages":null},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.07.004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2595830","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":"Metal-catalyzed CH activation/functionalization: The fundamentals","authors":"Fares Roudesly,&nbsp;Julie Oble,&nbsp;Giovanni Poli","doi":"10.1016/j.molcata.2016.06.020","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.06.020","url":null,"abstract":"<div><p>An isolated C<img>H bond in a molecule has a very low reactivity owing to the large kinetic barrier associated to the C<img>H bond cleavage and the apolar nature of this bond. For this reason, the selective reactivity of such a non-functional group is under active study since several decades and is still regarded as the Holy Grail in chemistry. Metal-catalyzed C<img>H activation/functionalization chemistry allows the step-economical and original construction of C<img>C as well as C<img>O and C<img>N bonds starting from hydrocarbons (or hydrocarbon fragments) without the need of prior non catalytic oxidation steps. Furthermore, it can be of utmost importance in the domain of multistep syntheses, and also in transformations of societal significance such as the conversion of methane into methanol. This tutorial review addresses to students and researchers who would like to become acquainted with this fascinating topic. After a brief historical introduction, the main mechanistic fundaments of metal-catalyzed C<img>H activation are exposed. Then, a selection of seminal advances and conceptual breakthroughs are presented.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":null,"pages":null},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.06.020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2660115","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 interplay of catalytic and gas-phase stages at oxidative conversion of methane: A review","authors":"Vladimir S. Arutyunov ,&nbsp;Ludmila N. Strekova","doi":"10.1016/j.molcata.2016.08.008","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.08.008","url":null,"abstract":"<div><p>The effective functionalization of C<img>H bond in methane, the main hydrocarbon component in Earth's crust and the most real source of energy for mankind in the nearest observable future, is undoubtedly can be regarded nowadays as one of the most important scientific and technological tasks. However, the usual practice of considering catalytic and gas-phase processes as independent technological branches seriously restricts the possibilities for a deeper understanding and technological optimization of real processes. The development of more effective technologies to convert methane and other gas-phase hydrocarbons into more valuable and demanded chemicals needs a complex approach based on the combined heterogeneous–homogeneous chemistry of these processes. A number of examples are used to illustrate the interconnection between heterogeneous catalytic and gas-phase processes in oxidative functionalization of methane. A number of potential possibilities for the optimization of the real heterogeneous–homogeneous chemistry of these processes are discussed.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":null,"pages":null},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.08.008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2660116","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":"Catalytic homogeneous oxidation of monoterpenes and cyclooctene with hydrogen peroxide in the presence of sandwich-type tungstophosphates [M4(H2O)2(PW9O34)2]n−, M = CoII, MnII and FeIII","authors":"Isabel C.M.S. Santos ,&nbsp;José A.F. Gamelas ,&nbsp;Tiago A.G. Duarte ,&nbsp;Mário M.Q. Simões ,&nbsp;M. Graça P.M.S. Neves ,&nbsp;José A.S. Cavaleiro ,&nbsp;Ana M.V. Cavaleiro","doi":"10.1016/j.molcata.2016.10.021","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.10.021","url":null,"abstract":"<div><p>Catalytic efficiency of tetrabutylammonium salts of sandwich tungstophosphates B‐α‐[M₄(H₂O)₂(PW₉O₃₄)₂]ⁿ⁻, M<!--> <!-->=<!--> <!-->Co^II, Mn^II, Fe^III, was studied in the oxidation of (<em>R</em>)-(+)-limonene, geraniol, linalool, linalyl acetate, carveol, and <em>cis</em>-cyclooctene with hydrogen peroxide, in acetonitrile. Oxidation of (<em>R</em>)-(+)-limonene gave limonene-1,2-diol as main product. Epoxidation of linalool takes place preferentially at the more substituted 6,7-double bond, the corresponding 6,7-epoxide reacting further, yielding furano- and pyrano-oxides, via intramolecular cyclization. Oxidation of linalyl acetate occurred preferentially at the more substituted 6,7-double bond for Mn₄(PW₉)₂, affording 6,7-epoxide at 82% selectivity. Linalyl acetate 1,2-epoxide was the major product with 51% and 77% selectivity for Co₄(PW₉)₂ and Fe₄(PW₉)₂, respectively. Oxidation of carveol occurred with very good conversions in the presence of Mn₄(PW₉)₂, Co₄(PW₉)₂ and Fe₄(PW₉)₂, yielding carvone and carveol 1,2-epoxide in similar amounts. Oxidation of <em>cis</em>-cyclooctene gave only the epoxide, while oxidation of geraniol at room temperature afforded 2,3-epoxygeraniol as the major product.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":null,"pages":null},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.10.021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2660120","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":"Cu(I)-catalyzed one-pot decarboxylation-alkynylation reactions on 1,2,3,4-tetrahydroisoquinolines and one-pot synthesis of triazolyl-1,2,3,4-tetrahydroisoquinolines","authors":"Birgit Gröll,&nbsp;Patricia Schaaf,&nbsp;Marko D. Mihovilovic,&nbsp;Michael Schnürch","doi":"10.1016/j.molcata.2016.07.013","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.07.013","url":null,"abstract":"<div><p>A facile and efficient method to introduce alkyne groups to the C-1 position of biologically interesting 1,2,3,4-tetrahydroisoquinolines via direct C<img>H-functionalization is reported. Various alkynylated N-substituted 1,2,3,4-tetrahydroisoquinolines could be obtained by using copper(I)-chloride as catalyst, alkynoic acids as alkyne source and t-BuOOH as oxidant, in a one-pot two-step decarboxylation- alkynylation reaction in moderate to high yields. Furthermore, a one-pot protocol of a three-step decarboxylation-alkynylation-1,3-dipolar cycloaddition reaction leading to 1-triazolyl-tetrahydroisoquinolines was developed, a hitherto unknown reaction cascade.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":null,"pages":null},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.07.013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"1737685","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":"Efficient functionalization of olefins by arylsilanes catalyzed by palladium anionic complexes","authors":"E. Silarska ,&nbsp;M. Majchrzak ,&nbsp;B. Marciniec ,&nbsp;A.M. Trzeciak","doi":"10.1016/j.molcata.2016.07.023","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.07.023","url":null,"abstract":"<div><p>The coupling of organosilanes and different olefins was performed efficiently in the presence of anionic complexes, [CA]₂[PdX₄] and [CA]₂[Pd₂X₆], where CA<!--> <!-->=<!--> <!-->imidazolium or pyridinium cation. The reaction proceeds according to a Pd(II)-mediated pathway, and Cu(OAc)₂ acts as the re-oxidant of Pd(0) formed during the catalytic process. High product yields were obtained for differently substituted olefins at 80<!--> <!-->°C in 4<!--> <!-->h. Styrylsilanes reacted in the same conditions giving unsymmetrical 1,3-dienes.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":null,"pages":null},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.07.023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"1737686","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":"Functionalization of the naturally occurring linalool and nerol by the palladium catalyzed oxidation of their trisubstituted olefinic bonds","authors":"Luciana A. Parreira ,&nbsp;Ana F. Azevedo ,&nbsp;Luciano Menini ,&nbsp;Elena V. Gusevskaya","doi":"10.1016/j.molcata.2016.07.033","DOIUrl":"https://doi.org/10.1016/j.molcata.2016.07.033","url":null,"abstract":"<div><p>Linalool and nerol, bio-renewable terpenic alkenyl alcohols found in many essential oils, were selectively oxidized by molecular oxygen in the presence of the chloride-free Pd(OAc)₂/<em>p</em>-benzoquinone catalytic system. An efficient dioxygen-coupled catalytic turnover was achieved in the absence of auxiliary electron-transfer mediators under 5–10<!--> <!-->atm of oxygen pressure. In both substrates, only one of two olefinic bonds was involved in the interaction with palladium, whereas the other one remained intact. Primary allylic acetates were formed as major reaction products: 8-linalyl acetate and 8-neryl acetate from linalool and nerol, respectively. In the case of linalool, the intramolecular cyclization product (known as herboxide), also resulted from the oxidation of the internal double bond, was also formed in significant amounts. All monoterpenic compounds obtained in the present work are natural products found in exotic plants or grape wines and are potentially useful as fragrance ingredients due to their pleasant scents.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":null,"pages":null},"PeriodicalIF":5.062,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.07.033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"2171629","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}