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Book Transition Metals in the Synthesis of Complex Organic Molecules

Download or read book Transition Metals in the Synthesis of Complex Organic Molecules written by Louis S. Hegedus and published by . This book was released on 2010 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: The third edition of Transition Metals in the Synthesis of Complex Organic Molecules is a comprehensive revision and significant expansion of the second edition. The clear and systematic approach to the formation, manipulation, and reactivity of organometallic complexes has been maintained. The book is divided into 10 chapters starting with general formalisms, electron counting, and basic principles of organometallic reaction mechanisms. The organic chemistry of transition metals is then presented by class of metal complex, with many examples of applications in the synthesis of complex natural products and pharmaceuticals. The book is ideal for advanced undergraduate and graduate students as well as all practicing synthetic organic chemists. It is written for organic chemists and offers an easy entry into the field of organotransition metal chemistry without requiring a background in inorganic chemistry.

Book Kinetics and Mechanism of Reactions of Transition Metal Complexes

Download or read book Kinetics and Mechanism of Reactions of Transition Metal Complexes written by Ralph G. Wilkins and published by Wiley-VCH. This book was released on 1991-08-28 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thoroughly revised and updated edition of one of the classics of kinetics text books continues the successful concept of the 1974 edition: In its first part, a simplified approach to the determination of rate laws and mechnisms is given steadily working up to complex situations. In the following chapters the principles developed there are extensively used in a comprehensive account of reactions of transition metal complexes, including reactions of biological signifacance. The text is illustrated by numerous figures and tables. Points of further interest are highlighted in special insets. 140 problems, taken from the original literature, enable the student to apply and deepen his newly acquired knowledge and make the book highly useful for courses in inorganic and organometallic reaction mechanisms. Furthermore, a wealth of over 1700 references renders it an indispensable work for the active researcher.

Book Synthesis Reactivity and Mechanistic Studies on Oxo Imido and Alkylidine Complexes of the Early Transition Metals

Download or read book Synthesis Reactivity and Mechanistic Studies on Oxo Imido and Alkylidine Complexes of the Early Transition Metals written by Jonathan Paul Mitchell and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Syntheses and Reactivity Studies of Transition Metal Complexes Featuring Metal Main Group Multiple Bonds

Download or read book Syntheses and Reactivity Studies of Transition Metal Complexes Featuring Metal Main Group Multiple Bonds written by Meg E. Fasulo and published by . This book was released on 2012 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ruthenium triflate complex Cp*(PiPr3)RuOTf (1) was generated from the reaction of Cp*(PiPr3)RuCl with Me3SiOTf in dibutyl ether. Complex 1 reacted with primary and secondary silanes to produce a family of Ru(IV) silyl dihydride complexes of the type Cp*(PiPr3)Ru(H)2(SiRR'OTf) (3 - 12). Structural analyses of complexes 8 (R = R' = Ph) and 12 (R = R' = fluorenyl) revealed the presence of a tetrahedral silicon center and a four-legged piano stool geometry about ruthenium. Anion abstraction from Cp*(PiPr3)Ru(H)2(SiHROTf) by [Et3Si*toluene][B(C6F5)4] afforded hydrogen-substituted cationic ruthenium silylene complexes [Cp*(PiPr3)Ru(H)2(=SiHR)][B(C6F5)4] (R = Mes (13), R = Si(SiMe3) (14)) that display a significant Ru - H ... Si interaction, as indicated by relatively large 2JSiH coupling constants (2JSiH = 58.2 Hz (13), 2JSiH = 37.1 Hz (14)). The syntheses of secondary silylene complexes [Cp*(PiPr3)Ru(H)2(=SiRR')][B(C6F5)4] (R = R' = Ph (15); R = Ph, R' = Me (16), R = R' = fluorenyl (17)) were also achieved by anion abstraction with [Et3Si*toluene][B(C6F5)4]. Complexes 15 - 17 do not display strong Ru - H ... Si secondary interactions, as indicated by very small 2JSiH coupling constant values. The cationic ruthenium silylene complex [Cp*(PiPr3)Ru(H)2(SiHMes)] [CB11H6Br6], a catalyst for olefin hydrosilations with primary silanes, was isolated and characterized by X-ray crystallography. Relatively strong interactions between the silylene Si atom and Ru-H hydride ligands appear to reflect a highly electrophilic silicon center. Kinetic and mechanistic studies on hydrosilations with this catalyst reveal a fast, initial addition of the Si-H bond of the silylene complex to the olefin. Subsequent migration of a hydride ligand to silicon produces a 16-electron intermediate, which can be trapped by olefin, resulting in inhibition of catalysis, or intercepted by the silane substrate. The latter reaction pathway, involving oxidative addition of the Si-H bond and a somewhat concomitant loss of product, is the rate-determining step in the catalytic cycle. Reactions of the cationic ruthenium silylene complexes [Cp*(PiPr3)Ru(H)2(=SiRR')][B(C6F5)4] (R = Mes, R' = H, 1; R = R' =Ph, 2) with alkenes, alkynes, ketones, and Lewis bases were explored. Addition of 1-hexene, 3,3-dimethylbut-1-ene, styrene, and cyclopentene to 1 afforded the disubstituted silylene products [Cp*(PiPr3)Ru(H)2(=SiMesR)][B(C6F5)4] (R = Hex, 3; R = CH2CH2tBu, 4; R = CH2CH2Ph, 5; R = C5H9, 6). Analogous reactions with 2-butyne and 3,3-dimethylbut-1-yne yielded the vinyl-substituted silylene complexes [Cp*(PiPr3)Ru(H)2(=Si(CR=CHR')Mes)][B(C6F)4] (R = R' = Me, 7; R = H, R' = tBu, 8). Complex 1 undergoes reactions with ketones to give the heteroatom-substituted silylene complexes [Cp*(PiPr3)Ru(H)2(=Si(OCHPhR)Mes)][B(C6F)4] (R = Ph, 9; R = Me, 10). Interestingly, complexes 3 - 8 display a weak interaction between the hydride ligands and the silicon center, while 9 and 10 exhibit a relatively large interaction (as determined by 2JSiH values). The reaction of isocyanates with 1 resulted in the silyl complexes [Cp*(PiPr3)Ru(H)2(Si(Mes)[n2-O(CH)(NC6H4R)][B(C6F5)4] (R = H, 11; R = CF3, 12), and an intermediate in this transformation is observed. Complex 2 was subjected to various Lewis bases to yield the base-stabilized silylene complexes [Cp*(PiPr3)Ru(H)2(SiPh2*L)][B(C6F)4] (L = DMAP, 13; L = Ph2CO, 14; L = PhCONH2, 15; L = NHMePh, 16, L = tBuSONH2, 18) and the reaction of 1 with NHMePh gave [Cp*(PiPr3)Ru(H)2(SiHMes*NHMePh)][B(C6F)4]. The cationic germylene complex [Cp*(PiPr3)Ru(H)2(=GeMes2)][OTf] (1) was synthesized from the reaction of Cp*(PiPr3)RuOTf with H2GeMes2, and addition of DMAP to 1 yielded the neutral germylene complex [Cp*(PiPr3)Ru(H)(=GeMes2) (2). The reaction of H3GeTrip and Cp*(PiPr3)RuCl gave the germyl complex Cp*(PiPr3)Ru(H)2(GeHTripCl) (3), which undergoes a reaction with Li(Et2O)2[B(C6F5)4] to afford the cationic H-substituted germylene complex [Cp*(PiPr3)Ru(H)2(=GeHTrip)][B(C6F5)4] (4). Addition of 1-hexene, 3,3-dimethylbut-1-ene, styrene, and allyl chloride to 4 afforded the disubstituted germylene products [Cp*(PiPr3)Ru(H)2(=GeTripR)][B(C6F5)4] (R = Hex, 5; R = CH2CH2Ph, 6; R = CH2CH2tBu, 7; R = CH2CH2CH2Cl, 8). Analogous reactions with 2-butyne and 3,3-dimethylbut-1-yne yielded the vinyl-substituted germylene complexes [Cp*(PiPr3)Ru(H)2(=Ge(CR=CHR')Trip)][B(C6F)4] (R = H, R' = tBu, 9; R = R' = Me, 10). New di(phosphine)-supported rhodium and iridium silyl complexes were synthesized. Reactions of the di(t-butylphosphino)ethane complex (dtbpe)Rh(CH2Ph) with Ph2SiH2 and Et2SiH2 resulted in isolation of (dtbpe)Rh(H)2(SiBnPh2) (1, Bn = CH2Ph) and (dtbpe)Rh(H)2(SiBnEt2) (2), respectively. Both 1 and 2 display strong interactions between the rhodium hydride ligands and the silyl ligand, as indicated by large 2JSiH values (44.4 and 52.1 Hz). The reaction of (dtbpm)Rh(CH2Ph) (dtbpm = di(t-butylphosphino)methane) with Mes2SiH2 gave the pseudo-three-coordinate Rh complex (dtbpm)Rh(SiHMes2) (3), which is stabilized in the solid state by agostic interactions between the rhodium center and two C - H bonds of a methyl substituent of a mesityl group. The analogous germanium compound (dtbpm)Rh(GeHMes2) (4) is also accessible. Complex 3 readily undergoes reactions with diphenylacetylene, phenylacetylene, and 2-butyne to give the silaallyl complexes (dtbpm)Rh[Si(CPh=CHPh)Mes2] (5), (dtbpm)Rh[Si(CH=CHPh)Mes2] (7), and (dtbpm)Rh(Si(CMe=CHMe)Mes2) (8) via net insertions into the Si - H bond. The germaallyl complexes (dtbpm)Rh[Ge(CPh=CHPh)Mes2] (6) and (dtbpm)Rh[Ge(CMe=CHMe)Mes2] (9) were synthesized under identical conditions starting from 4. The reaction of (dtbpm)Rh(CH2Ph) with 1 equiv of TripPhSiH2 yielded (dtbpm)Rh(H)2[5,7-diisopropyl-3-methyl-1-phenyl-2,3-dihydro-1H-silaindenyl-kSi] (11), and catalytic investigations indicate that both (dtbpm)Rh(CH2Ph) and 11 are competent catalysts for the conversion of TripPhSiH2 to 5,7-diisopropyl-3-methyl-1-phenyl-2,3-dihydro-1H-silaindole. A dtbpm-supported Ir complex, [(dtbpm)IrCl]€2, was used to access the dinuclear bridging silylene complexes [(dtbpm)IrH](SiPh2)(Cl)2[(dtbpm)IrH] (12) and [(dtbpm)IrH](SiMesCl)( -Cl)(H)[(dtbpm)IrH] (13). The reaction of [(dtbpm)IrCl]2 with a sterically bulky primary silane, (dmp)SiH3 (dmp = 2,6-dimesitylphenyl), allowed isolation of the mononuclear complex (dtbpm)Ir(H)4(10-chloro-1-mesityl-5,7-dimethyl-9,10-dihydrosilaphenanthrene-Si) (14), in which the dmp substituent has undergone C-H activation. The dichloride complex Cp*(Am)WCl2 (1, Am = [(iPrN)2CMe]- ) reacted with the primary silanes PhSiH3, (p-tolyl)SiH3, (3,5-xylyl)SiH3, and (C6F5)SiH3 to produce the W(VI) (silyl)trihydrides Cp*(Am)W(H)3(SiHPhCl) (2), Cp*(Am)W(H)3(SiHTolylCl) (3), Cp*(Am)W(H)3(SiHXylylCl) (4), and Cp*(Am)W(H)3[SiH(C6F5)Cl] (5). In an analogous manner, 1 reacted with PhSiH2Cl to give Cp*(Am)W(H)3(SiPhCl2) (6). Complex 6 can alternatively be quantitatively produced from the reaction of 2 with Ph3CCl. NMR spectroscopic studies and X-ray crystallography reveal an interligand H ... Si interaction between one W - H and the chlorosilyl group, which is further supported by DFT calculations. Complexes of Ru(II) containing the pincer ligand [-N(2-PPh2-4-Me-C6H3)2] (PNPPh) were prepared. The complex (PNPPhH)RuCl2 (1) was treated with 2 equiv AgOTf to produce the triflate complex (PNPPhH)Ru(OTf)2 (2). Complex 1 was also treated with an excess of NaBH4 to give a bimetallic complex [(PNPPh)RuH3]2 (3). A number of methods, including X-ray crystallography, NMR spectroscopy, and computational studies, were used to probe the structure of 3. Addition of Lewis bases to 3 resulted in octahedral complexes containing a hydride ligand trans to a dihydrogen ligand.

Book Structural and Mechanistic Studies of Some Transition metal Complexes Containing Various Phosphorus and Carbon Donor Ligands

Download or read book Structural and Mechanistic Studies of Some Transition metal Complexes Containing Various Phosphorus and Carbon Donor Ligands written by Jonathan Michael Rosalky and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Configurational Equilibria

    Configurational Equilibria

    Book Details:
  • Author : Mary Jane Incorvia Mattina
  • Publisher :
  • Release : 1970
  • ISBN :
  • Pages : 294 pages

Download or read book Configurational Equilibria written by Mary Jane Incorvia Mattina and published by . This book was released on 1970 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Kinetic and Mechanistic Studies on Some Transition Metal Complexes

Download or read book Kinetic and Mechanistic Studies on Some Transition Metal Complexes written by Mohammed Delwar Hussain and published by . This book was released on 1968 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Synthesis reactivity and mechanistic studies on oxo imido and alkylidene complexes of the early transition metals

Download or read book Synthesis reactivity and mechanistic studies on oxo imido and alkylidene complexes of the early transition metals written by Jonathan Paul Mitchell and published by . This book was released on 1992 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Mechanistic Studies and Design of Supported Transition Metal Complexes

Download or read book Mechanistic Studies and Design of Supported Transition Metal Complexes written by Terry Zhi Hao Gani and published by . This book was released on 2020 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supported transition metal (TM) complexes are an emerging class of materials with many potential applications in the chemical industry ranging from separations to catalysis. They offer increased tunability and often also improved performance over their bulk heterogeneous counterparts. Their study and rational design is, however, accompanied by several unique considerations and challenges that we address in this thesis. The first part of the thesis broadly develops and applies computational screening strategies for supported TM complexes. First, we detail how weak C-H[superscript ...]O hydrogen bonds can be exploited to increase selectivity of ferrocenium (Fc+)-based polymer electrode materials for formate adsorption over perchlorate adsorption while maintaining reasonable desorption rates in the reduced (ferrocene, Fc) state. Through a systematic characterization of formate and perchlorate interactions with a small (ca. 40) but diverse set of functionalized Fc+ complexes, we identify and rationalize design rules for functionalizations that simultaneously increase selectivity for formate in aqueous environments while permitting rapid release from Fc. Next, we screen a larger (ca. 500) set of model Fe(II) complexes for methane hydroxylation in order to assess if linear free energy relationships (LFERs), extensively developed to reduce the computational cost of computationally screening bulk heterogeneous catalysts, can also be applied to supported single-site TM catalysts. We demonstrate that structural distortions achievable in porous frameworks and chelating ligands break these LFERs by altering relative d-orbital splittings, thereby revealing a potential strategy for improving the activity of these catalysts. Finally, to address a particularly pervasive issue in density functional theory (DFT) studies of first-row open-shell TM complexes, we investigate how the fraction of exact exchange parameterized in the functional affects computed reaction and spin-splitting energies. We rationalize this sensitivity in terms of differences in metal-ligand electron delocalization and introduce the metal-ligand bond valence as a simple, yet robust, descriptor that unifies understanding of exchange sensitivity for catalytic properties and spin-state ordering in TM complexes.

Book Synthesis AndRreactivity of Copper I Copper II Platinum II and Platinum IV Complexes with Non dative Heteroatomic Ligands

Download or read book Synthesis AndRreactivity of Copper I Copper II Platinum II and Platinum IV Complexes with Non dative Heteroatomic Ligands written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Examples of late transition metal complexes with amido, alkoxo and sulfido ligands are relatively rare in part due to enhanced reactivity based on nucleophilicity and basicity of the heteroatomic ligand (X). The highly nucleophilic and basic character of formally anionic X ligands coordinated to metal centers with low oxidation states is attributable to the disruption of ligand-to-metal pi-bonding. Examples of common reactivity for these systems include nucleophilic addition reactions, insertions of unsaturated substrates, acid/base chemistry with acidic C-H bonds and C-H activation reactions with aromatic substrates. In addition to fundamental reactivity studies, these complexes also offer opportunities for incorporation into catalytic processes. Late transition metal complexes with non-dative X ligands have been implicated in several C-X bond forming reactions and have been demonstrated to activate non-polar substrates. Thus, in order to advance the understanding of these reactive systems and to exploit the prospects for synthetic applications toward small molecule transformations, further study is warranted. Presented herein is the study of (IPr)Cu(NR2), (IPr)Cu(OR) and (IPr)Cu(SR) {IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene} complexes in the catalytic hydroamination of electron-deficient olefins toward regioselective formation of C-N, C-O and C-S bonds. The substrate scope encompasses alkyl and aryl amines, including primary and secondary variants, as well as alcohols and thiols. Olefins with cyano, acyl, and ester functionalities and vinylarenes are reactive. In a demonstration of potential application, the hydroamination of p-nitrostyrene with N-methylbenzylamine by (IPr)Cu(NHPh) provides a straight-forward single-step route to an anti-arrhythmic agent. Mechanistic studies are consistent with a reaction pathway that involves intermolecular nucleophilic addition of the Cu-amido to free olefin. In an effort to obtain more active catalyst systems that.

Book Dissertation Abstracts International

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2002 with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt: