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Developments in the hydrogenation of challenging substrates utilising transition metal complexesCarpenter, Ian January 2015 (has links)
This thesis describes the developments of new protocols for the hydrogenation of challenging substrates. Three specific substrates were highlighted for study after an initial review of the literature; benzofurans, esters and bulky ketones. Chapter 1 details a review of the hydrogenation of challenging unsaturated substrates, highlighting areas where development is still required. Chapter 2 describes studies on the hydrogenation of 2,3-benzofuran. While a benzofuran hydrogenation catalysts was optimised, severe conditions were required to facilitate the reaction, and not found to be applicable for more elaborate substrates. We therefore considered an alternative process of enantioselective hydrogenation of benzofuranyl ketones followed by heterogeneous hydrogenation. A good process for transfer hydrogenation of a range of these hitherto unstudied substrates was developed along with greater understanding. The hydrogenation of esters is another challenge in the catalytic reduction field, so was also selected for study, with the results described in Chapter 3. After screening a range of catalysts of types [RuCl₂ (diphosphine)(diamine)] and [RuCl₂ (PNX)(DMSO)], good catalysts were identified. Successful hydrogenation of a range of esters, under mild conditions was achieved using [RuCl₂ (1,3-bisdiphenylphosphinepropane)(2-aminomethylpyridine)] using high concentrations of base co-catalyst. [RuCl₂ ((2-(diphenylphosphanylbenzyl)ethane-1,2-diamine)(DMSO)] combined with 15-25 mol% of a basic co-catalyst have been shown to be active at near ambient conditions in the hydrogenation of aromatic esters. Chapter 4 related to studies where the activity of Ru, Ir and Rh complexes of the same tridentate ligand were tested in the hydrogenation of ketones that would be regarded as sluggish substrates. Highly active and selective catalysts for the hydrogenation of bulky acetophenone derivatives were found using iridium complexes of PNX ligands (formed in situ). The highest selectivity was obtained with acetophenone substrates containing iso-propyl and cyclohexyl substituents, or medicinally important piperdinyl groups. In the best cases over 90% e.e. was observed with high conversions and with only 0.1 mol% of catalyst.
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Novel synthesis of 2-substituted - benzofuran derivatives /Parinya Theramongkol. January 1976 (has links) (PDF)
Thesis (M.Sc. (Organic Chemistry))--Mahidol University, 1976.
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Hypervalent Iodine Reagents in Metal-Free Arylations and Vinylations : Investigation of Suitable Coupling Partners and Synthesis of New ReagentsStridfeldt, Elin January 2017 (has links)
This thesis concerns the development of metal-free reactions to obtain carbon-heteroatom and carbon-carbon bonds. This is achieved by transferring carbon ligands from hypervalent iodine reagents to suitable nucleophiles. The bulk of the work presented herein concerns arylation of oxygen and nitrogen nucleophiles, using the well-known diaryliodonium salts as aryl sources. In the first project, O-arylation of the oxime ethyl acetohydroxamate was studied. It was found that electron-poor as well as electron-rich aryl moieties could be transferred successfully to this nucleophile. Furthermore, the protocol could be extended to a sequential one-pot synthesis of benzo[b]furans. This method allowed for a fast synthesis of the natural product stemofuran A and formal syntheses of other natural products. In a successive project, O-arylation of hydroxide and aliphatic alkoxides was investigated. It is known that electron-poor aryl moieties can be transferred to these nucleophiles in moderate to high yields. However, combined with more electron-rich diaryliodonium salts, a large amount of side products were formed. These were suppressed upon addition of aryne traps, suggesting that aryne pathways are competing with the desired ligand coupling. It was also observed that secondary alcohols were oxidized to the corresponding ketones. The mechanism for this oxidation was investigated and aryne pathways could be excluded. Instead we suggest that the carbinol hydrogen gets deprotonated via an internal mechanism, after the alkoxide has coordinated to the iodonium salt. Highly sterically congested alkyl aryl ethers could be obtained in high yields by combining tertiary alcohols with ortho-blocked diaryliodonium salts. Next, N-arylation of secondary acyclic amides was studied using acetanilide as the model substrate. This procedure was suitable for transfer of electron-poor as well as ortho-substituted aryl moieties, but attempts to transfer very electron-rich aryl groups were unsuccessful. On the other hand, the amides displayed a complementary reactivity, allowing phenylation of electron-rich amides. In the final project, a one-pot synthesis of the cyclic iodonium reagent vinylbenziodoxolone is presented. These compounds have not been explored as reagents earlier. Initial screenings showed that the vinyl moiety could be transferred to nitrocyclohexane with opposite regioselectivity compared to the acyclic analogue of the reagent. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Manuscript.</p>
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Chinese compound formula on post-stroke rehabilitation.January 2008 (has links)
Chan, Chun Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 147-161). / Abstracts in English and Chinese. / Chapter Chaper 1 --- Introduction --- p.1 / Chapter 1.1 --- General introduction to cerebral stroke --- p.1 / Chapter 1.2 --- Different types of cerebral stroke --- p.2 / Chapter 1.3 --- Statistics --- p.3 / Chapter 1.4 --- Symptoms of cerebral stroke --- p.4 / Chapter 1.5 --- Complications of cerebral stroke --- p.5 / Chapter 1.6 --- Risks and preventions of cerebral stroke --- p.6 / Chapter 1.7 --- Cerebral stroke treatment --- p.8 / Chapter 1.8 --- Post stroke rehabilitation --- p.11 / Chapter 1.9 --- Mechanisms of stroke --- p.15 / Chapter 1.9.1 --- Energy production failure and loss of ionic homeostasis --- p.15 / Chapter 1.9.2 --- Excitotoxicity --- p.16 / Chapter 1.9.3 --- Calcium ions mediated toxicity --- p.17 / Chapter 1.9.4 --- Passive neuronal cell death --- p.18 / Chapter 1.9.5 --- Oxidative stress --- p.19 / Chapter 1.9.6 --- Inflammation --- p.22 / Chapter 1.9.7 --- Apoptosis --- p.25 / Chapter 1.10 --- Potential therapeutic agents for cerebral stroke --- p.24 / Chapter 1.10.1 --- Anti-oxidative enzyme and free radical scavengers --- p.24 / Chapter 1.10.2 --- Ions channel blockers and glutamate antagonists --- p.26 / Chapter 1.10.3 --- Anti-inflammatory agent --- p.28 / Chapter 1.10.4 --- Anti-apoptotic agent --- p.28 / Chapter 1.11 --- Experimental model of cerebral ischemia-reperfusion --- p.29 / Chapter 1.11.1 --- In vitro model (oxygen and glucose deprivation model) --- p.29 / Chapter 1.11.2 --- In vivo model (Middle cerebral artery occlusion) --- p.31 / Chapter 1.12 --- Traditional Chinese Medicine (TCM) --- p.32 / Chapter 1.12.1 --- General Introduction to Traditional Chinese Medicine --- p.32 / Chapter 1.12.2 --- TCM and cerebral stroke --- p.33 / Chapter 1.12.3 --- Chinese compound formula --- p.34 / Chapter 1.12.4 --- Introduction to individual herb --- p.34 / Chapter 1.12.4.1 --- Astragali Radix (Pinyin name: Huangqi) --- p.34 / Chapter 1.12.4.2 --- Rhizoma Chuanxiong (Pinyin name: Chuanxiong) --- p.35 / Chapter 1.12.4.3 --- Radix Salviae Miltorrhizae (Pinyin name: Danshen) --- p.35 / Chapter 1.12.4.4 --- Cassia Obtusifolia Linne (Pinyin name: Jue Ming Zi) --- p.36 / Chapter 1.12.4.5 --- Radix Glycyrrhizae (Pinyin name: Gancao) --- p.37 / Chapter 1.12.4.6 --- Radix Angelicae Sinensis (Pinyin name: Dongquai) --- p.37 / Chapter 1.12.4.7 --- Paeoniae Veitchii Radix (Pinyin name: Chi Shao) --- p.38 / Chapter 1.12.5 --- Salvianolic acid B --- p.39 / Chapter 1.13 --- Aim of study --- p.40 / Chapter Chapter 2 --- Materials and Methods --- p.41 / Chapter 2.1 --- Materials --- p.41 / Chapter 2.1.1 --- Drug --- p.41 / Chapter 2.1.1.1 --- Herbal Medicine --- p.41 / Chapter 2.1.1.2 --- Herbal extraction of PSR --- p.42 / Chapter 2.1.1.3 --- Herbal extraction of individual herb --- p.43 / Chapter 2.1.1.4 --- Salvianolic acid B --- p.43 / Chapter 2.1.2 --- Chemical --- p.44 / Chapter 2.1.3 --- Animal --- p.48 / Chapter 2.2 --- Methods --- p.49 / Chapter 2.2.1 --- (AAPH)- induced erythrocyte hemolysis --- p.49 / Chapter 2.2.2 --- Cell Culture study --- p.51 / Chapter 2.2.2.1 --- Cell Line --- p.51 / Chapter 2.2.2.2 --- Cell differentiation --- p.52 / Chapter 2.2.2.3 --- In vitro model of ischemia - Oxygen glucose deprivation (OGD) experiment --- p.53 / Chapter 2.2.2.4 --- Cell viability assay --- p.54 / Chapter 2.2.3 --- In vivo Study --- p.54 / Chapter 2.2.3.1 --- Cerebral blood flow (CBF) measurement --- p.54 / Chapter 2.2.3.2 --- In vivo transient focal cerebral ischemia model - Middle cerebral artery occlusion (MCAo) --- p.55 / Chapter 2.2.3.3 --- Administration of PSR --- p.57 / Chapter 2.2.3.4 --- Administration of salvianolic acid B (SAB) --- p.59 / Chapter 2.2.3.5 --- Measurement of brain infarct volume --- p.60 / Chapter 2.2.3.6 --- In vivo anti-oxidative enzyme activity determination in the brain --- p.61 / Chapter 2.2.3.6.1 --- Brain tissue preparation --- p.61 / Chapter 2.2.3.6.2 --- Tissue homogenization and protein extraction --- p.61 / Chapter 2.2.3.6.3 --- Protein concentration determination --- p.63 / Chapter 2.2.3.6.4 --- Catalase activity determination in the brain --- p.63 / Chapter 2.2.3.6.5 --- Glutathione Peroxidase (GPx) activity determination in the brain --- p.64 / Chapter 2.2.3.6.6 --- The Superoxide Dismutase (SOD) activity determination in the brain --- p.65 / Chapter 2.2.3.7 --- Behavioral Evaluation --- p.66 / Chapter 2.2.3.7.1 --- Neurological behavioural test --- p.66 / Chapter 2.2.3.7.2 --- Shuttle box escape experiment --- p.67 / Chapter 2.3 --- Statistical analyses --- p.71 / Chapter Chapter 3 --- Results --- p.72 / Chapter 3.1 --- In vitro model of ischemia - Oxygen glucose and deprivation (OGD) experiment --- p.72 / Chapter 3.2 --- AAPH assay of PSR --- p.75 / Chapter 3.3 --- AAPH assay of individual herb --- p.77 / Chapter 3.4 --- Brain slices after middle cerebral artery occlusion (MCAo) experiment --- p.81 / Chapter 3.5 --- Brain infarct volume of single dose protocol --- p.83 / Chapter 3.6 --- Neurological behavioural test of single dose protocol --- p.85 / Chapter 3.7 --- Brain infarct volume of double doses protocol --- p.87 / Chapter 3.8 --- Neurological behavioural test of double doses protocol --- p.89 / Chapter 3.9 --- Determination of superoxide dismutase (SOD) activity in the brain --- p.91 / Chapter 3.10 --- Determination of glutathione peroxidase (GPx) activity in the brain --- p.93 / Chapter 3.11 --- Determination of catalase activity in the brain --- p.95 / Chapter 3.12 --- Brain infarction volume of Salvianolic acid B (SAB) treatment --- p.98 / Chapter 3.13 --- Neurological behavioural test of SAB treatment --- p.100 / Chapter 3.14 --- Shuttle box performance in training and testing series --- p.102 / Chapter 3.15 --- Change in shuttle box performance (% avoidance c.f. last day of training) in testing series --- p.104 / Chapter 3.16 --- Escape latency in testing and training series --- p.107 / Chapter 3.17 --- Change in escape latency (c.f. last day of training) in testing series --- p.109 / Chapter 3.18 --- Brain infarct volume of shuttle box escape experiment --- p.112 / Chapter 3.19 --- Neurological score in shuttle box escape experiment --- p.114 / Chapter Chapter 4 --- Discussion --- p.117 / Chapter 4.1 --- The protective effect of PSR in in vitro oxygen and glucose deprivation (OGD) on human neuroblastoma SH-SY5Y cell line --- p.117 / Chapter 4.1.1 --- OGD model and cell line --- p.117 / Chapter 4.1.2 --- Protective effect of PSR in OGD experiment --- p.118 / Chapter 4.1.3 --- Free radical scavenging property of PSR --- p.120 / Chapter 4.2 --- The protective effects of PSR in in vivo middle cerebral artery (MCAo) model --- p.121 / Chapter 4.2.1 --- The shortcomings of in vitro OGD model --- p.121 / Chapter 4.2.2 --- Development of in vivo MCAo model and TTC staining --- p.122 / Chapter 4.2.3 --- Protective effect of PSR in MCAo experiment (single dose protocol) --- p.124 / Chapter 4.2.4 --- Protective effect of PSR in MCAo experiment (double doses protocol) --- p.125 / Chapter 4.2.5 --- The effect of PSR toward neurological deficits --- p.127 / Chapter 4.2.6 --- Anti-oxidative effects of PSR in MCAo model --- p.128 / Chapter 4.3 --- The protective effects of SAB in in vivo middle cerebral artery (MCAo) model --- p.130 / Chapter 4.3.1 --- Free radical scavenging property of different herbs --- p.130 / Chapter 4.3.2 --- Selection of pure compound that used to treat stroke --- p.131 / Chapter 4.3.3 --- Protective effect of Salvianolic B in MCAo experiment --- p.132 / Chapter 4.3.4 --- The effect of SAB toward neurological deficits --- p.133 / Chapter 4.4 --- The effects of PSR and SAB on stroked rats' performance in shuttle box escape experiment --- p.134 / Chapter 4.4.1 --- Establishment of shuttle box escape experiment --- p.134 / Chapter 4.4.2 --- Effects of PSR and SAB on avoidance performance --- p.135 / Chapter 4.4.3 --- Effects of PSR and SAB on escape latency --- p.138 / Chapter 4.5 --- Assessment on the contribution of SAB to the protective effect of PSR --- p.140 / Chapter 4.6 --- Comparison of acute and chronic testing --- p.140 / Chapter 4.6.1 --- The protective effect of the drugs (Histopathological examination) --- p.140 / Chapter 4.6.2 --- The severity of motor deficit (Neurological score) --- p.141 / Chapter Chapter 5 --- Conclusion and Future prospect --- p.143 / Chapter 5.1 --- Conclusion --- p.143 / Chapter 5.2 --- Future prospect --- p.144 / References --- p.147
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Marcacao, distribuicao e estudo cinetico da benziodarona com I-131 em ratos da linhagem WistarSHIMIZU, SANAE 09 October 2014 (has links)
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01036.pdf: 919968 bytes, checksum: 8432333a9ebb3f09ef6cf9cbf84c9622 (MD5) / Dissertacao (Mestrado) / IEA/D / Instituto de Biociencias, Universidade de Sao Paulo - IB/USP
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Marcacao, distribuicao e estudo cinetico da benziodarona com I-131 em ratos da linhagem WistarSHIMIZU, SANAE 09 October 2014 (has links)
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01036.pdf: 919968 bytes, checksum: 8432333a9ebb3f09ef6cf9cbf84c9622 (MD5) / Dissertacao (Mestrado) / IEA/D / Instituto de Biociencias, Universidade de Sao Paulo - IB/USP
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Chemical dissection of eIF4A-mediated translationBordeleau, Marie-Eve January 2007 (has links)
No description available.
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Kinetic and Thermodynamic Studies of Thrombin InhibitorsAbdel, Aziz May 28 February 2013 (has links)
Sulfated low molecular weight lignins (LMWLs), CDSO3 and FDSO3, designed recently as macromolecular mimetics of heparin, were found to exhibit potent anticoagulant activity. Small molecules based on the same scaffold, SBD and SBT, showed promising thrombin inhibition. We were able to address the mechanism of the inhibition using Michaelis-Menten kinetics. All the molecules were found to be allosterically impairing thrombin activity using either noncompetitive or uncompetitive mechanism. Absence of competition with hirugen, an exosite 1 ligand, and competition with polymeric heparin points to exosite 2 as the site of interaction for these inhibitors. Yet mixed competition results with other exosite 2 ligands indicated that the molecules utilize different sub-sites within exosite 2 for interaction. Site-directed mutagenesis was used to pin point the key residues important for inhibition. All of all positively charged exosite 2 residues were mutated one at a time to alanine to abolish its charge. The data showed that Arg93 and Arg175 are the major residues involved in CDSO3 binding. FDSO3 showed a progressively greater defect in inhibition with double point mutations, the triple mutant Arg93,97,101Ala displayed a 50 fold drop in inhibition. A single mutant, Arg173Ala, displayed 22-fold reduction in IC50 of SBD, while Arg233Ala was the only mutation that impaired SBT inhibition. This proves the fact that inspite of the structural similarity between the two polymers and the two small molecules, thtey do not share the same binding space in exosite 2. To understand the types of interactions involved in thrombin interaction with the polymers, we resorted to salt-dependence studies. This showed that CDSO3 had fewer ionic contacts with thrombin, with most of its binding energy derived from non-ionic interactions. FDSO3 on the other hand had a balanced contribution of ionic and non-ionic forces. Thermodynamic studies showed that both polymers have a positive ΔCp of binding, which proves the involvement of electrostatic forces and signals the burial of the polar residues on thrombin exosite 2. These molecules offer a rare chance to study thrombin allostery. Little is known about the interplay between exosite 2, active site and sodium binding site. The allosteric nature of inhibition indicated that, for the first time, a link is proven to exist between exosite 2 and the active site that could be used to inhibit the enzyme. The presence of sodium was found to enhance the binding of FDSO3 at exosite 2, which establish the energetic coupling between exosite 2 and sodium binding site. The results identify novel binding sub-sites within exosite 2 that are energetically coupled to thrombin’s catalytic function and linked to the sodium binding site. The design of high affinity small molecules based on LMWLs scaffold presents major opportunities for developing clinically relevant, allosteric modulators of thrombin.
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Exploring the iodine(III)-mediated ring contraction: new substrates, novel conditions and asymmetric reactions / Explorando a contração de anel mediada por iodo(III): novos substratos, novas condições e reações assimétricasAhmad, Anees 28 August 2015 (has links)
In the first section this thesis includes the reactivity of various oxygen-containing benzofused cyclic alkenes with HTIB (Hydroxy(tosyloxy)iodobenzene). Instead of getting ring contraction products, 2H-chromene resulted in 4H-chromenes together with trans-addition products. Only cis-addition products were isolated from 4-methyl-2H-chromene. Ring contraction was observed in dihydrobenzoxepines and 2,2-dimethyl-2H-chromenes giving functionalized chromanes and benzofurans, respectively. In the second part, the ring contraction of 1,2-dihydronaphthalenes using HTIB was expanded to substrates bearing oxygen and nitrogen substituents in the aromatic ring. The N-protecting groups Fmoc and Bz are stable under the reaction conditions giving indanes in 64-77% yield. The Ts-protected substrate gave only addition products. Acetoxy and benzoyloxy alkenes afforded indanes in 60-71% yield. A new and efficient method for the oxidative rearrangement (ring contraction and expansion) of alkenes using in situ generated iodine(III) is described in the third section. The protocol uses inexpensive and stable chemicals (PhI, mCPBA and TsOH) furnishing rearrangement products in yields comparable to those obtained using commercially available iodine(III). Additionally, a new route for the one step transformation of 4-methyl-1,2-dihydronaphthalene into 1-methyl-2-tetralone using mCPBA and TsOH was developed. In the last section is presented the reactivity of chiral iodine(III) with 1,2-dihydronaphthalenes. The hypervalent iodine species is generated in situ from chiral aryl iodide, which is prepared in one high yield step from inexpensive starting materials. Protected (Ac, Bz and Fmoc) amine alkenes gave indanes in 60-75% and 58-64% ee. In the same way, oxygenated substrates afforded acetal in 41-61% yield and 54-78% ee. Ring contraction products were obtained in 77-88% yield and 34-40% ee when 1-methyl and aryl substituted alkenes were utilized. / A primeira parte desta tese inclui a reatividade de vários alquenos benzofundidos cíclicos contendo oxigênio com HTIB (Hidróxi(tosilóxi)iodobenzeno). Em vez de obter os produtos de contração de anel, 2H-cromeno resultou em 4H-cromenos, juntamente com produtos trans-adição. Apenas produtos de adição de cis foram isolados a partir de 4-metil-2H-cromeno. Contração do anel foi observada em di-hidrobenzoxepinas e 2,2-dimetil-2H-cromenos dando cromanos funcionalizados e benzofuranos, respectivamente. Na segunda parte, a contração de anel de 1,2-di-hidronaftalenos usando HTIB foi expandida para substratos contendo substituintes de oxigênio e de nitrogênio no anel aromático. Os grupos N-protetores Fmoc e Bz são estáveis sob as condições de reação fornecendo indanos em 64-77% de rendimento. O substrato protegido com Ts deu apenas os produtos de adição. Acetóxi e benzoilóxi alquenos geraram indanos em 60-71% de rendimento. Um método novo e eficiente para o rearranjo oxidativo (contração e expansão do anel) de alquenos utilizando iodo(III) gerado in situ é descrito na terceira parte. O protocolo utiliza reagentes baratos e estáveis (PhI, mCPBA e TsOH) fornecendo produtos de rearranjo com rendimentos comparáveis aos obtidos utilizando iodo(III) disponível comercialmente. Além disso, um método para a transformação em uma etapa de 4-metil-1,2-di-hidronaftaleno em 1-metil-2-tetralona utilizando mCPBA e TsOH foi desenvolvido. Na última parte é apresentada a reatividade de iodo(III) quiral com 1,2-di-hidronaftalenos. A espécie de iodo hipervalente é gerada in situ a partir de iodeto de arila quiral, o qual é preparado em uma etapa em rendimento elevado a partir de materiais de partida baratos. Amino alquenos protegidos (Ac, Bz e Fmoc) deram indanos em 60-75% de rendimento e 58-64% ee. Da mesma forma, os substratos oxigenados proporcionram acetais em 41-61% de rendimento e 54-78% de ee. Produtos de contração de anel foram obtidos em 77-88% de rendimento e 34-40% de ee quando alquenos 1-metil e aril substituídos foram utilizados.
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Exploring the iodine(III)-mediated ring contraction: new substrates, novel conditions and asymmetric reactions / Explorando a contração de anel mediada por iodo(III): novos substratos, novas condições e reações assimétricasAnees Ahmad 28 August 2015 (has links)
In the first section this thesis includes the reactivity of various oxygen-containing benzofused cyclic alkenes with HTIB (Hydroxy(tosyloxy)iodobenzene). Instead of getting ring contraction products, 2H-chromene resulted in 4H-chromenes together with trans-addition products. Only cis-addition products were isolated from 4-methyl-2H-chromene. Ring contraction was observed in dihydrobenzoxepines and 2,2-dimethyl-2H-chromenes giving functionalized chromanes and benzofurans, respectively. In the second part, the ring contraction of 1,2-dihydronaphthalenes using HTIB was expanded to substrates bearing oxygen and nitrogen substituents in the aromatic ring. The N-protecting groups Fmoc and Bz are stable under the reaction conditions giving indanes in 64-77% yield. The Ts-protected substrate gave only addition products. Acetoxy and benzoyloxy alkenes afforded indanes in 60-71% yield. A new and efficient method for the oxidative rearrangement (ring contraction and expansion) of alkenes using in situ generated iodine(III) is described in the third section. The protocol uses inexpensive and stable chemicals (PhI, mCPBA and TsOH) furnishing rearrangement products in yields comparable to those obtained using commercially available iodine(III). Additionally, a new route for the one step transformation of 4-methyl-1,2-dihydronaphthalene into 1-methyl-2-tetralone using mCPBA and TsOH was developed. In the last section is presented the reactivity of chiral iodine(III) with 1,2-dihydronaphthalenes. The hypervalent iodine species is generated in situ from chiral aryl iodide, which is prepared in one high yield step from inexpensive starting materials. Protected (Ac, Bz and Fmoc) amine alkenes gave indanes in 60-75% and 58-64% ee. In the same way, oxygenated substrates afforded acetal in 41-61% yield and 54-78% ee. Ring contraction products were obtained in 77-88% yield and 34-40% ee when 1-methyl and aryl substituted alkenes were utilized. / A primeira parte desta tese inclui a reatividade de vários alquenos benzofundidos cíclicos contendo oxigênio com HTIB (Hidróxi(tosilóxi)iodobenzeno). Em vez de obter os produtos de contração de anel, 2H-cromeno resultou em 4H-cromenos, juntamente com produtos trans-adição. Apenas produtos de adição de cis foram isolados a partir de 4-metil-2H-cromeno. Contração do anel foi observada em di-hidrobenzoxepinas e 2,2-dimetil-2H-cromenos dando cromanos funcionalizados e benzofuranos, respectivamente. Na segunda parte, a contração de anel de 1,2-di-hidronaftalenos usando HTIB foi expandida para substratos contendo substituintes de oxigênio e de nitrogênio no anel aromático. Os grupos N-protetores Fmoc e Bz são estáveis sob as condições de reação fornecendo indanos em 64-77% de rendimento. O substrato protegido com Ts deu apenas os produtos de adição. Acetóxi e benzoilóxi alquenos geraram indanos em 60-71% de rendimento. Um método novo e eficiente para o rearranjo oxidativo (contração e expansão do anel) de alquenos utilizando iodo(III) gerado in situ é descrito na terceira parte. O protocolo utiliza reagentes baratos e estáveis (PhI, mCPBA e TsOH) fornecendo produtos de rearranjo com rendimentos comparáveis aos obtidos utilizando iodo(III) disponível comercialmente. Além disso, um método para a transformação em uma etapa de 4-metil-1,2-di-hidronaftaleno em 1-metil-2-tetralona utilizando mCPBA e TsOH foi desenvolvido. Na última parte é apresentada a reatividade de iodo(III) quiral com 1,2-di-hidronaftalenos. A espécie de iodo hipervalente é gerada in situ a partir de iodeto de arila quiral, o qual é preparado em uma etapa em rendimento elevado a partir de materiais de partida baratos. Amino alquenos protegidos (Ac, Bz e Fmoc) deram indanos em 60-75% de rendimento e 58-64% ee. Da mesma forma, os substratos oxigenados proporcionram acetais em 41-61% de rendimento e 54-78% de ee. Produtos de contração de anel foram obtidos em 77-88% de rendimento e 34-40% de ee quando alquenos 1-metil e aril substituídos foram utilizados.
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