Phosphorus ligands derived from terpene alcohols as stereochemical probes
| dc.contributor.author | Wang, Jihong | |
| dc.contributor.supervisor | Stobart, Stephen R. | |
| dc.date.accessioned | 2018-07-19T19:40:49Z | |
| dc.date.available | 2018-07-19T19:40:49Z | |
| dc.date.copyright | 1995 | en_US |
| dc.date.issued | 2018-07-19 | |
| dc.degree.department | Department of Chemistry | |
| dc.degree.level | Doctor of Philosophy Ph.D. | en_US |
| dc.description.abstract | A series of optically active tertiary phosphorus ligands, [special characters omitted] (R = bornyl, menthyl, or isopinocamphyl; n = 1, 2, or 3, 1 – 9), containing chiral alkoxy groups derived from natural terpene alcohols, menthol, borneol, and isopinocampheol, are synthesized and characterized by various spectroscopic techniques. The reactions of these ligands with iron and cobalt carbonyl complexes are carried out, giving monomeric mono- and di-substituted iron(0) and dimeric di-substituted cobalt carbonyl complexes [special characters omitted]. The characterization of these complexes by IR and NMR spectrometries is discussed. Results of preliminary studies on hydroformylation reaction under oxo conditions catalysed by several cobalt complexes are presented. Pyrazolyl bridged di-iridium(I) systems, [special characters omitted], are prepared as diastereomers with unequal thermodynamic distribution. The X-ray crystal structure of 41 shows cocrystallization of the two diastereomers in the same unit cell, which provides 1:1 kinetic distribution of the two isomers. Kinetic studies of the interconversion from the kinetic ratio to the thermodynamic ratio of the two diastereomers in 41 indicates the existence of a slow inversion process of the six-membered central metallocycle in 41. Oxidative addition of Mel to 41 generates a pair of diastereomeric adducts (43) in kinetic distribution, which is slowly converted to its thermodynamic distribution, implying a very slow reductive elimination of Mel. Oxidative additions of exo- and endo-norbornyl iodide to [special characters omitted] results in same product (44). Possible mechanisms for this process are discussed. Bisdiphenylphosphinoalkylsilane containing chiral menthoxy group [special characters omitted] is prepared and characterized. Its four-coordinate square planar platinum complex [special characters omitted] and five-coordinate iridium(I) complex [special characters omitted] are synthesized. Isomerizations of 49 and its CO adducts, [special characters omitted] (55 and 56), are studied in relation to their methyl analogues. | en_US |
| dc.description.scholarlevel | Graduate | en_US |
| dc.identifier.uri | http://hdl.handle.net/1828/9746 | |
| dc.language | English | eng |
| dc.language.iso | en | en_US |
| dc.rights | Available to the World Wide Web | en_US |
| dc.subject | Ligands | en_US |
| dc.subject | Terpenes | en_US |
| dc.subject | Stereochemistry | en_US |
| dc.title | Phosphorus ligands derived from terpene alcohols as stereochemical probes | en_US |
| dc.type | Thesis | en_US |