EBookClubs

Read Books & Download eBooks Full Online

EBookClubs

Read Books & Download eBooks Full Online

Book Studies in the Synthesis of New Derivatised Cyclopentadienyl Ligands and Some of Their Transition Metal Complexes

Download or read book Studies in the Synthesis of New Derivatised Cyclopentadienyl Ligands and Some of Their Transition Metal Complexes written by Ronan M. Bellabarba and published by . This book was released on 2000 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Metallocenes in Regio and Stereoselective Synthesis

Download or read book Metallocenes in Regio and Stereoselective Synthesis written by Marko Hapke and published by Springer Nature. This book was released on with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Synthesis of New Cyclopentadienyl and Indenyl Transition Metal Complexes

Download or read book Synthesis of New Cyclopentadienyl and Indenyl Transition Metal Complexes written by Gloria U. Obuzor and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards

Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2006 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Development of Novel Cyclopentadienone Based Transition Metal Complexes for Catalytic and Electrocatalytic Transfer Hydrogenation of Polar Bonds

Download or read book Development of Novel Cyclopentadienone Based Transition Metal Complexes for Catalytic and Electrocatalytic Transfer Hydrogenation of Polar Bonds written by Weiwei Wu and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Transition Metal Complexes of Oxazolinylboranes and Cyclopentadienyl bis oxazolinyl borates

Download or read book Transition Metal Complexes of Oxazolinylboranes and Cyclopentadienyl bis oxazolinyl borates written by and published by . This book was released on 2012 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research presented and discussed in this dissertation involves the synthesis of transition metal complexes of oxazolinylboranes and cyclopentadienyl-bis(oxazolinyl)borates, and their application in catalytic enantioselective olefin hydroamination and acceptorless alcohol decarbonylation. Neutral oxazolinylboranes are excellent synthetic intermediates for preparing new borate ligands and also developing organometallic complexes. Achiral and optically active bis(oxazolinyl)phenylboranes are synthesized by reaction of 2-lithio-2-oxazolide and 0.50 equiv of dichlorophenylborane. These bis(oxazolinyl)phenylboranes are oligomeric species in solid state resulting from the coordination of an oxazoline to the boron center of another borane monomer. The treatment of chiral bis(oxazolinyl)phenylboranes with sodium cyclopentadienide provide optically active cyclopentadienyl-bis(oxazolinyl)borates H[PhB(C5H5)(OxR)2] [OxR = Ox4S-iPr, Me2, Ox4R-iPr, Me2, Ox4S-tBu]. These optically active proligands react with an equivalent of M(NMe2)4 (M = Ti, Zr, Hf) to afford corresponding cyclopentadienyl-bis(oxazolinyl)borato group 4 complexes {PhB(C5H4)(OxR)2}M(NMe2)2 in high yields. These group 4 compounds catalyze cyclization of aminoalkenes at room temperature or below, providing pyrrolidine, piperidine, and azepane with enantiomeric excesses up to 99%. Our mechanistic investigations suggest a non-insertive mechanism involving concerted C-N/C-H bond formation in the turnover limiting step of the catalytic cycle. Among cyclopentadienyl-bis(oxazolinyl)borato group 4 catalysts, the zirconium complex {PhB(C5H4)(Ox4S-iPr, Me2)2}Zr(NMe2)2 ({S-2}Zr(NMe2)2) displays highest activity and enantioselectivity. Interestingly, S-2Zr(NMe2)2 also desymmetrizes olefin moieties of achiral non-conjugated aminodienes and aminodiynes during cyclization. The cyclization of aminodienes catalyzed by S-2Zr(NMe2)2 affords diastereomeric mixture of cis and trans cylic amines with high diasteromeric ratios and excellent enantiomeric excesses. Similarly, the desymmetrization of alkyne moieties in S-2Zr(NMe2)2-catalyzed cyclization of aminodiynes provides corresponding cyclic imines bearing quaternary stereocenters with enantiomeric excesses up to 93%. These stereoselective desymmetrization reactions are significantly affected by concentration of the substrate, temperature, and the presence of a noncyclizable primary amine. In addition, both the diastereomeric ratios and enantiomeric excesses of the products are markedly enhanced by N-deuteration of the substrates. Notably, the cationic zirconium-monoamide complex [S-2Zr(NMe2)][B(C6F5)4] obtained from neutral S-2Zr(NMe2)2 cyclizes primary aminopentenes providing pyrrolidines with S-configuration; whereas S-2Zr(NMe2)2 provides R-configured pyrrolidines. The yttrium complex S-2YCH2SiMe3 also affords S-configured pyrrolidines by cyclization of aminopentenes, however the enantiomeric excesses of products are low. An alternative optically active yttrium complex {PhB(C5H4)(Ox4S-tBu)2}YCH2SiMe3 ({S-3}YCH2SiMe3) is synthesized, which displays highly enantioselective in the cyclization of aminoalkenes at room temperature affording S-configured cyclic amines with enantiomeric excesses up to 96%. A noninsertive mechanism involving a six-membered transition state by a concerted C-N bond formation and N-H bond cleavage is proposed for {S-3}YCH

Book Synthesis and Asymmetric Reactivity of Electronically and Sterically Differentiating Chiral Cyclopentadienyl Metal Complexes

Download or read book Synthesis and Asymmetric Reactivity of Electronically and Sterically Differentiating Chiral Cyclopentadienyl Metal Complexes written by Ronald Lee Halterman and published by . This book was released on 1985 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Some studies on cyclopentadienyl and carbonyl complexes of transition metals

Download or read book Some studies on cyclopentadienyl and carbonyl complexes of transition metals written by Jon Armistice McCleverty and published by . This book was released on 1963 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Design and Synthesis of Electronically and Sterically Variable Chiral Cyclopentadienyl Transition Metal Complexes and Their Application in Asymmetric Transformations

Download or read book Design and Synthesis of Electronically and Sterically Variable Chiral Cyclopentadienyl Transition Metal Complexes and Their Application in Asymmetric Transformations written by Timothy Michael Ramsey and published by . This book was released on 1994 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Mono cyclopentadienyl Complexes of Titanium and Vanadium

Download or read book Mono cyclopentadienyl Complexes of Titanium and Vanadium written by Jan Nieman and published by . This book was released on 1983 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Design and Synthesis of New Ligand Systems for Transition Metal Catalysed Carbon carbon Cross coupling Hydrogenation and Hydrosilation

Download or read book Design and Synthesis of New Ligand Systems for Transition Metal Catalysed Carbon carbon Cross coupling Hydrogenation and Hydrosilation written by Daniel Carleton and published by . This book was released on 2013 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: An ever increasing global requirement for consumables consequently increases the demand for often non-renewable resources, resulting in the need for greater efficiencies in synthetic processes. In order to achieve this goal, the field of organometallic catalysis has been ever growing to support the ideals of cleaner and greener chemistry. In this thesis studies concerning a series of new bidentate donor ligands employing both the NHC and PYA donor groups for use in transition metal catalysis is presented. The successful synthesis of the bidentate ligand N,N'-dimethyl-N''-pyridin-4-yl nicotinamide with both a remote NHC and PYA donor groups is reported, along with the synthesis of the precursor materials 1-methyl-3-(2-oxo-2-(pyridin-2-ylamino)ethyl)-1H-imidazol-3-ium and 1-methyl-3-(2-oxo-2-(pyridin-4-ylamino)ethyl)-1H-imidazol-3-ium for the formation of other bidentate ligands incorporating the imidazolium NHC and PYA donor groups. The iridium complex IrH(L-R4)(CO)(PPh3)2 containing the new ligand L-R4 was prepared through reaction of N,N'-dimethyl-N''-pyridin-4-yl nicotinamide with Vaskas Complex. Chapter one explains the ideology behind green chemistry and our constant drive to maintain a clean and green planet. Chapter two describes the effect of donor groups on a metal centre with focus on the NHC and PYA donor groups and their advantages over previous work in this area. Chapter three describes the development of synthetic routes to the new target ligands and chapter four explains the studies involving the metal precursor substrates and ligand coordination. Chapter five contains details of the relevant experimental data. The work described in this thesis will provide an excellent starting point for those wishing to further explore the synthesis and study of bidentate NHC and PYA donor ligands in catalysis by transition metals.