烯烴是世界上最被廣泛應用的化工原料之一。最近我們通過含氮雜環卡賓鎳氫化物來催化氫化烯化反應，用廉價的單取代簡單烯烴成功合成了更有價值的不對稱1，1-偕二取代烯烴。雖然它們的對映體可以由傳統的手性拆分方法在實驗室中獲得，但卻不太可能實際應用於工業中，從而限制了此新方法的可應用性。因此，本文中我們透過使用烯烴醛耦合反應生成手性含氮雜環卡賓鎳氫化物 [(NHC)NiH]OTf，並以此為催化劑，將其應用在溫和條件下高選擇性的催化不對稱氫化烯化反應。另外，上述烯烴醛耦合反應的副產物 (烯丙基矽醚) 亦可成為基板，通過催化受控的替換反應，最後合成並得出較高取代的烯烴。基於烯丙基磷酸二芳酯為目前在生物學上中一種重要的研究項目，以及其當前製備的困難，我們通過形成碳磷鍵來探索這些烯丙基矽醚的可應用性。故此，在現有的磷碳反應文獻和 Ritter 反應的鼓舞下，我們提供開發烯丙基磷酸二芳酯在溫和條件下的催化製備方法。此方法除可補充現有製備方法的不足外，亦能增加此類化合物有較高的取代基靈活性。 / Alkenes are one of the most versatile chemical feedstock in chemistry. Among the numerous preparative strategies, hydroalkenylation (H.A.) by using N-heterocyclic carbene (NHC)-NiH reported recently by our group represents a novel strategy to access synthetically valuable unsymmetric terminal 1, 1-disubstituted alkenes (DSA) from widely available α-alkenes. Their enantiomers could be obtained by classic chiral resolution methods in laboratory but may not be practical in industry, which limits the applications of this new methodology. As a result, herein we developed a catalytic asymmetric H.A. with high selectivities under mild conditions based on a chiral [(NHC)NiH]OTf catalyst generated in situ from alkene-aldehyde (A.A.) coupling. Since the above A.A. coupling by-product (allyl silyl ethers) is a structural motif potentially amenable for higher alkene catalytic synthesis by a controlled substitution, and because of the current difficulties in the preparation of biologically important allyl diarylhosphonates, we also explore the use of those allyl silyl ethers by means of C-P bond formation. Inspired by both existing phosphonylation literatures and Ritter reaction, we developed a catalytic preparation method for those compounds which complements the existing methods with a high substituent flexibility under milder conditions. / Detailed summary in vernacular field only. / Chan, Chun Wa. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / Table of Contents --- p.i / Acknowledgement --- p.iv / Abstract --- p.v / Abstract (Chinese Version) --- p.vi / Abbreviation --- p.vii / Chapter CHAPTER 1 --- IMPORTANCE OF GREENER ALKENE SYNTHESIS AND INTRODUCTION OF NHC AND ITS APPLICATION IN 1,1-DSA SYNTHESIS --- p.1 / Chapter 1.1 --- Synthesis of Higher Alkenes with Different Substitution Patterns from Simple α-Alkene --- p.1 / Chapter 1.2 --- Introduction of NHC --- p.6 / Chapter 1.2.1 --- Electronic Property Comparison --- p.6 / Chapter 1.2.2 --- NHCMetal Complex Stability --- p.8 / Chapter 1.2.3 --- Steric Parameter Comparison --- p.9 / Chapter 1.3 --- Challenges in Using NHC-NiH as Hydroalkenylation (H.A.) Catalyst --- p.10 / Chapter 1.4 --- A New Solution for Catalytic NHC-NiH Based H.A. and 1,1-DSA Preparation --- p.14 / Chapter 1.5 --- Objective and Approach for Asymmetric Cross-H.A. --- p.18 / Chapter CHAPTER 2 --- PRELIMINARY STUDY ON LIGAND STRUCTURALACTIVITY-RELATIONSHIPS (SAR) --- p.21 / Chapter 2.1 --- Structural Criteria of Chiral NHCs for Asymmetric H.A. --- p.21 / Chapter 2.2 --- Successful Asymmetric H.A. Using Selected Chiral C2 Symmetric Ligands Rationalized by Stereo-Chemical Models --- p.24 / Chapter CHAPTER 3 --- STUDIES AND OPTIMIZATION OF CHIRAL C₁-NHC CATALYZED H.A. --- p.28 / Chapter CHAPTER 4 --- SECOND GENERATION OF CATALYST --- p.41 / Chapter 4.1 --- A New Lead: Substrates Electronic and Steric Effects on Ee --- p.41 / Chapter 4.2 --- Ee Enhancement by Using Electronic Modified N[superscriptAr] NHC --- p.48 / Chapter 4.3 --- Scope of Asymmetric Hydroalkenylation --- p.55 / Chapter 4.4 --- Conclusion --- p.62 / Chapter REFERENCE --- p.64 / Chapter APPENDIX (I) - --- ASYMMETRIC HYDROALKENYLATION --- p.71 / EXPERIMENTAL SECTION --- p.71 / GC CHROMATOGRAM --- p.178 / HPLC CHROMATOGRAM --- p.192 / Chapter REFERENCE OF APPENDIX (I) --- p.207 / Chapter APPENDIX (II) - --- APPLICATIONS OF ALLYL SILYL ETHER OBTAINED FROM HA CATALYST GENERATION: SELECTIVE PREPARATION OF ALLYL DIARYLPHOSPHONYLATION --- p.209 / Chapter A.1 --- Importance of Allyl Phosphonates --- p.209 / Chapter A.2 --- Conventional Methods and Challenges of Allyl Phosphonates Preparation with Higher Alkenes Functionality --- p.210 / Chapter A.3 --- Objective and Approach --- p.212 / Chapter A.4 --- Preliminary Results of Allyl Diarylphosphonylation --- p.213 / Chapter A.4.1 --- Strategies for Chemoselectivity Improvement --- p.215 / Chapter A.4.2 --- Proposed Mechanism: Ritter-like Reaction Pathway --- p.219 / Chapter A.5 --- Scope of Allyl Diarylphosphonylation --- p.222 / Chapter A.6 --- Introduction of Allyl Arylation --- p.228 / Chapter A.7 --- Scope of Allyl Arylation --- p.229 / Chapter A.8 --- Conclusion --- p.232 / EXPERIMENTAL SECTION --- p.234 / Chapter REFERENCE OF APPENDIX (II) --- p.274 / Chapter NMR --- SPECTRA COMPOUNDS FOR APPENDIX (I) -ASYMMETRIC HYDROALKENYLATION --- p.280 / Chapter COMPOUNDSFOR APPENDIX (II) - --- APPLICATIONS OF ALLYL SILYL ETHER OBTAINED FROM HA CATALYST GENERATION: SELECTIVE PREPARATION OF ALLYL DIARYLPHOSPHONYLATION --- p.388

No description available.

The thesis is concerned with approaches to substituted 2-phenyl- 1,3-oxathiolans and their cycloreversion to olefins. 2-(α-Methoxybenzylthio)acetophenone (l) was prepared by <u>in situ</u> alkylation of the thiolate generated by aminolysis of 0-ethyl-S-phenacyldithiocarbonate with α-chlorobenzyl methyl ether. Reduction of (l) with lithium aluminium hydride gave 2-(α-methoxybenzylthio)—1— phenylethanol which cyclised in the presence of <u>p</u>-toluenesulphonic acid to give 2,5-diphenyl-l,3-oxathiolan. α-(α'-Methoxybenzylthio)acetone (2), was prepared by a similar route to that used for (l). Compounds (1) and (2) and various other a-thiosubstituted ketones were investigated as potential starting materials for the synthesis of substituted β—(α-methoxybenzylthio)alcohols but the transformations attempted were unsuccessful. A reasonably flexible synthesis of substituted oxathiolans and hence the corresponding olefins was developed starting from α—(benzylthio)ketones. The olefins prepared were 2-methyl—3—phenyl—2— butene, 1,2-dimethylcyclohexene and the Z-(3) and E-(4) 3,4—dimethylhex— 3—enes. Alkylation of the a-(benzylthio)ketones proceeded regio— specifically α- to the thio and keto groups. Subsequent reaction with organometallic reagents gave β-benzylthioalcohols. Generally alkyllithiums gave the best yields and higher stereoselectivities in these additions. The benzylthio group was cleaved with sodium/ ammonia to give β-mercaptoalcohols which were condensed with benzaldehyde to give 2-phenyl-l,3-oxathiolans. Treatment of the oxathiolans with lithium diisopropylamide resulted in cycloreversion to olefins in high yields (75-100%). Stereochemical integrity was maintained throughout the reactions used to convert the β-benzylthioalcohols into olefins and consequently the stereoselectivity was determined at the β-benzylthioalcohol forming step. Thus the ratio found for (3) to (4) synthesised from a 3-benzylthioalcohol prepared by reaction of methyllithium with 3-benzylthio-3- methyl-4—hexanone was 3:7, whereas when the β-benzylthioalcohol was prepared from 3-benzylthio-3-methyl-2-pentanone by an ethyllithium reaction the ratio of (3) to (4) subsequently obtained was 6:4.

He, Lisi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 69-73). / Abstracts in English and Chinese. / Acknowledgement --- p.I / Table of Contents --- p.II / Abstract --- p.III / Abstract (Chinese Version) --- p.IV / Abbreviation --- p.V / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- "Synthesis of Terminal 1,1 -Disubstituted Olefins" --- p.1 / Chapter 1.2 --- Nickel Hydride Reactions with Olefins --- p.5 / Chapter 1.3 --- Objective and Approach --- p.16 / Chapter CHAPTER 2 --- RESULTS AND DISCUSSION --- p.20 / Chapter 2.1 --- Reaction Condition Optimization --- p.20 / Chapter 2.2 --- Substrates Scope Expansion --- p.27 / Chapter 2.3 --- Examples of Post-coupling Modifications --- p.35 / Chapter 2.4 --- Application in a sp2-sp3 Heck-like Reaction --- p.38 / Chapter CHAPTER 3 --- CONCLUSION --- p.43 / APPENDIX EXPERIMENTAL --- p.46 / REFERENCE --- p.69 / GC CHROMATOGRAMS & NMR SPECTRA FOR NEW COMPOUNDS

Includes a list of publications by the author arising from this thesis. / Bibliography: leaves 174-176. / 178 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Studies the reactivity of metal alkynyl fragments, in particular the formation of compounds containing two or more alkynes, resulting in the preparation of complexes with interesting properties and reactivities. / Thesis (Ph.D.)--Adelaide University, Dept. of Chemistry, 2001

Includes a list of publications by the author arising from this thesis. / Bibliography: leaves 174-176. / 178 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Studies the reactivity of metal alkynyl fragments, in particular the formation of compounds containing two or more alkynes, resulting in the preparation of complexes with interesting properties and reactivities. / Thesis (Ph.D.)--Adelaide University, Dept. of Chemistry, 2001

Ph.D. (Chemistry) / Compounds 3-ferrocenylpyrazole (L1) 3-ferrocenyl-5-methylpyrazole (L2) and 4- ferrocenyl-1-methyl diketone (L7) were synthesized according to literature procedure, while compounds 3-ferrocenylpyrazolyl-methylenepyridine (L3), 3-ferrocenyl-5- methylpyrazolyl-methylenepyridine (L4), 3-ferrocenylpyrazolyl-ethyl amine (L5) and 3- ferrocenyl-5-methylpyrazolyl-ethylamine (L6) were prepared by phase transfer alkylation of the 2,6-bis(bromomethyl)pyridine or 2-bromoethylamine with the appropriate ferrocenylpyrazole L1 or L2 in a 1:1 ratio. These compounds L3-L6 show structural isomers labelled a and b. The isomers were in a ratio of 4:1 for L3 and L4 while for L5 and L6 the isomers were 2:1 ratio...

The synthesis of 1,2-bis(5-isobenzofuranyl)ethene by two routes is described. The first route involved generation of 1,2-bis(5-isobenzofuranyl)ethene from a bis(acetal) precursor under basic conditions. However, the synthesis was lengthy with low-yielding steps, which led to it being abandoned. The second route involved generation of 1,2-bis(5-isobenzofuranyl)ethene from a bis(oxabicyclic) precursor with 3,6-di(2'-pyridyl)-s-tetrazine. Napththo[1,2-c:5,6-c] difuran and 1,2-bis(5isobenzofuranyl)ethene were used to construct novel cyclophanes by double Diels-Alder reactions with bis(maleimide)s. NMR, AM1 modeling, and X-ray studies of the cyclophanes are discused. Attempts to prepare phenanthro[2,3-c:6,7-c] difuran and its cyclophanes are discussed. None was successful, and investigations were hampered by the inability to obtain sufficient quantities of starting materials. Finally, several suggestions are given for improving the syntheses of 1,2-bis(5- isobenzofuranyl)ethene, phenanthro[2,3-c:6,7-c]difuran, and their cyclophanes. Future directions, such as the functionalization of the double bond of 1,2-bis(5-isobenzofuranyl)ethene, aromatization of the oxabicyclic rings of the cyclophanes, and further X-ray studies are discussed. / x, 122 leaves : ill. ; 28 cm.