chương 1 cũng nêu tóm tắt về phương pháp tổng hợp, đặc trưng hóa lý và một số các ứng dụng của ba loại vật liệu Cu-MOF-74, Cu2(OBA)2(BPY), MOF-235. Chương 2: Trình bày về thực nghiệm và kết quả của phân tích đặc trưng cấu trúc của Cu-MOF-74, Cu2(OBA)2(BPY), MOF-235. Các loại vật liệu được tổng hợp bằng phương pháp nhiệt dung môi và được phân tích các đặc trưng hóa lý bằng phương pháp nhiễu xạ tia X dạng bột (P-XRD), phổ hồng ngoại (FT-IR), kính hiển vi điện tử quét (SEM), kính hiển vi điện tử truyền qua (TEM), đo diện tích bề mặt bằng phương pháp hấp phụ đẳng nhiệt nitrogen, phương pháp nhiệt trọng lượng (TGA). Chương 3: Trình bày kết quả khảo sát và bàn luận về hoạt tính xúc tác của Cu-MOF- 74 cho phản ứng ether hóa trực tiếp giữa N-(quinolin-8-yl)benzamides với alcohols/phenols.
Hoạt tính xúc tác của MOF-235 cho phản ứng oxy hóa cộng vòng giữa benzyl alcohols và 2-aminophenols/2-aminothiophenols. Hoạt tính xúc tác của Cu2(OBA)2(BPY) trong phản ứng tổng hợp quinazolines, 4H-3,1-benzoxazines. Các phản ứng được khảo sát tính dị thể và tái sử dụng xúc tác trong điều kiện phản ứng. Chương 4: Trình bày tóm tắt về các kết quả đạt được cũng như các đóng góp chính của luận án, đồng thời đề xuất một số hướng nghiên cứu tiếp theo.
ii ABSTRACT Metal–organic frameworks (MOFs) are a well-known class of materials having the potential to become homo-hetero bridge. Compared with homogeneous catalysts, MOF catalysts can be recycled and reutilized for several times; while compared with conventional heterogeneous catalysts, MOFs have structural and chemical tunability. Metalorganic frameworks based on copper or iron metal sites have been used as catalysts for carbonheteroatom bond forming reactions. These copper-based MOFs or iron-based MOFs are promising owing to the utilization of non-precious and less toxic metal salt species.
Herein; Cu-MOF-74, Cu2(OBA)2(BPY), MOF-235 were synthesized by solvothermal method, and characterized by P-XRD, SEM, TEM, TGA, FT-IR, nitrogen physisorption measurements. Catalytic activities of these MOFs were investigated through carbonheteroatom bond forming reactions. In fact, Cu-MOF-74 was used as a catalyst for the direct etherification of N-(quinolin-8-yl)benzamides with alcohols/phenols. Besides, the synthesis of some N,N-, N,O-, N,S-heterocyclic compounds was studied via two approaches.
One approach was based on the oxidative cyclization reaction between 2-aminophenols/2-aminothiophenols and alcohols catalyzed by MOF-235. The other was a one-pot, two-step process which involved the condensation of aldehydes with 2-aminobenzylamines/2-aminobenzyl alcohols/ 1,2- phenylenediamines in catalyst-free conditions, followed by oxidative dehydrogenation of CN bond catalyzed by Cu2(OBA)2(BPY). All the surveyed catalysts were examined for the heterogeneity and reutilization under reaction conditions. To the best of our knowledge, these transformations under the studied reaction conditions have not been previously mentioned.
iii ACKNOWLEDGMENT This thesis has been carried out at Ho Chi Minh University of Technology since 2014. It may not be a very long time for someone else, but it will always be the suffering time as well as the best time in my life. I have never ever thought that I could get through this tough time in life. Fortunately, there always are my warmhearted and enthusiastic scientific advisors accompanying with me to my success.
The motivation of them always cheer me up at the right time and help me to go ahead to the final target. I can never give enough my thanks to Prof. Phan Thanh Son Nam and Assoc. Truong Vu Thanh.
It is impossible to recount all supports from my advisors, but these will be in my heart for the remaining of my life. It is an absolute misstep if I could not give my grateful thanks to Assoc. Pham Thanh Quan, Assoc. Le Thi Hong Nhan, Dr.
Phan Thi Hoang Anh. All my lecturers are so kindness to boost me up whenever I got troubles to conduct the thesis or even some problems happened in personal life. Additionally, I would like to send my great thanks to all friends that I met in the laboratory for their excellent helps during the period of carrying experiments. I give my sincerely thanks to Ha Quang Hiep, Doan Hoai Son, Duong Ngoc Tan Xuan, To Anh Tuong, Dang Van Hieu.
Among these friends, Ha Quang Hiep was the first person I met in the lab, who not only instructed me the lab instruments but also helped me close the gap between me with others. Finally, I would like to express my profound gratitude to my parents and also to my partner for providing me perfect support and encouragement during the entire course even in the hard time of writing this thesis. Tran Boi Chau iv TABLE OF CONTENTS 1. Introduction to metalorganic frameworks.
Possibility of catalytic application of MOFs. Limitations of MOFs as catalysts. The prospects of MOFs as catalysts. Factors affecting catalytic activities of MOFs.
Influence of synthetic methods. Influence of ligands on catalytic performances. Influence of secondary building units. Influence of reaction solvents.
MOF-235, Cu-MOF-74 and Cu2(OBA)2(BPY). Synthesis, structure and physicochemical properties of MOF-235. Synthesis, structure and physicochemical properties of Cu2(OBA)2(BPY). Synthesis, structure and physicochemical properties of Cu-MOF-74.
Carbonheteroatom bond forming reactions for the synthesis of benzo-fused heterocycles. Carbonheteroatom bond forming reactions for the synthesis of aryl ethers. Aims and projects. Materials and instrumentation.
Synthesis of Cu-MOF-74. Synthesis of Cu2(OBA)2(BPY). Synthesis of MOF-235. Results and discussion.
Characterization of Cu2(OBA)2(BPY). Characterization of Cu-MOF-74. Characterization of MOF-235. Catalytic activity of MOF-235 for the synthesis of N,O- and N,S- Heterocycles.
Materials and instruments. Catalytic activity of Cu2(OBA)2(BPY) for the synthesis of N,N- and N,O- Heterocycles. Materials and instruments. Catalytic activity of Cu-MOF-74 for the synthesis of aryl ethers.
Materials and instruments. Results and discussion. Catalytic activity of MOF-235 for the synthesis of N,O- and N,S- Heterocycles. Catalytic activity of Cu2(OBA)2(BPY) for the synthesis of N,N- and N,O- Heterocycles.
Catalytic activity of Cu-MOF-74 for the synthesis of aryl ethers. Contribution of this thesis. 87 vii LIST OF FIGURES Figure 1. Schematic presentation for the construction of typical coordination polymers/MOFs from molecular building blocks [9].
Typical curves observed in hot filtration test. Different type of MOF active sites, including metal nodes, functionalized organic linkers, and guest species in the pores [31]. The XRD patterns and the corresponding SEM images for the ZIF-8 samples synthesized by different methods (spray drying: ZIF-8-SP, microwave: ZIF-8-MW, room temperature: ZIF-8-RT, solvothermal: ZIF-8-SV) [32]. Coordination environment of copper in Cu2(OBA)2(BPY) [47].
(a) Coordination environment of Cu(II) centers in Cu-MOF-74 after thermal solvent removal. (b) Inorganic SBUs crystalline framework (c) 3D honeycomb structure of Cu-MOF-74. Two possible paths for the conversion of amidine [86]. A model of pillared-grid MOFs where circles indicate bimetal paddlewheels, red lines represent grid-forming ligands and blue lines represent pillar ligands [118].
(a) Amino-functionalized tetracarboxylate ligand. (b) Large spherical cages with diameter about 11 Å. P-XRD of the Cu2(OBA)2(PBY). FT-IR spectra of (a) the Cu2(OBA)2(BPY), (b) H2OBA, (c) 4,4’-bipyridine.
TGA analysis of the Cu2(OBA)2(BPY). (a) P-XRD, (b) SEM micrograph, (c) TEM micrograph of the synthesized Cu-MOF-74. (a) Nitrogen adsorption/desorption isotherm, (b) Pore size distribution of the Cu-MOF-74. TGA analysis of the Cu-MOF-74.
FT-IR spectra of (a) the Cu-MOF-74, (b) 2,5-dihydroxyterephthalic acid. P-XRD of the MOF-235. SEM micrograph of the MOF-235. TEM micrograph of the MOF-235.
FT-IR spectra of (a) the MOF-235, (b) 1,4-benzenedicarboxylic acid. Nitrogen adsorption/desorption isotherm of the MOF-235. Pore size distribution of the MOF-235. TGA analysis of the MOF-235.
Yield of 2-phenylbenzo[d]oxazole versus temperature. Yield of 2-phenylbenzo[d]oxazole versus oxidant. Yield of 2-phenylbenzo[d]oxazole versus oxidant quantity. Yield of 2-phenylbenzo[d]oxazole versus solvent.
Yield of 2-phenylbenzo[d]oxazole versus catalyst amount. Yield of 2-phenylbenzo[d]oxazole versus reactant molar ratio. Leaching test of solid iron-based framework. Yield of 2-phenylbenzo[d]oxazole versus catalyst poison.
Yield of 2-phenylbenzo[d]oxazole versus radical trapping reagent.10 Yield of 2-phenylbenzo[d]oxazole versus homogeneous iron catalyst. Yield of 2-phenylbenzo[d]oxazole versus heterogeneous catalyst. Catalyst reutilizing investigation. P-XRD results of the new (a) and reutilized (b) catalyst.
FT-IR results of the new (a) and reutilized (b) catalyst. Yield of 2-(4-nitrophenyl)quinazoline versus heterogeneous catalyst. Yield of 2-(4-nitrophenyl)quinazoline versus solvent. Yield of 2-(4-nitrophenyl)quinazoline in the case of omission of each reagent.
Yield of 2-(4-nitrophenyl)quinazoline versus homogeneous catalyst. Leaching test of solid copper-based framework. Reusability of Cu2(OBA)2(BPY). P-XRD of the fresh (a) and reused (b, after 5 runs) Cu2(OBA)2(BPY).
Yield of 2-ethoxy-N-(quinolin-8-yl)benzamide versus base. Yield of 2-ethoxy-N-(quinolin-8-yl)benzamide versus solvent. Yield of 2-ethoxy-N-(quinolin-8-yl)benzamide versus temperature. Yield of 2-ethoxy-N-(quinolin-8-yl)benzamide versus oxidant.
Yield of 2-ethoxy-N-(quinolin-8-yl)benzamide versus catalyst amount. Yield of 2-ethoxy-N-(quinolin-8-yl)benzamide versus pyridine volume. Yield of 2-ethoxy-N-(quinolin-8-yl)benzamide versus amount of base. Yield of 2-ethoxy-N-(quinolin-8-yl)benzamide versus heterogeneous catalyst.
Reaction conversion versus heterogeneous catalyst.31 Yield of 2-ethoxy-N-(quinolin-8-yl)benzamide versus homogeneous catalyst. Reaction conversion versus homogeneous catalyst. Leaching test of solid copper-based framework. Catalyst reutilizing studies.
P-XRD of fresh (a) and reused catalysts (b). 80 x LIST OF SCHEMES Scheme 1. Direct arylation of benzothiazole with aryl halide [50]. Reaction of aryl iodides with N-H nucleophiles catalyzed by aCu-MOF-74 [59].
Cross coupling approaches to form benzazoles [73-76]. Synthesis of 4H-3,1-benzoxazines [78]. Phillip’s method in the synthesis of benzazoles [79]. Plausible reaction for Phillip benzazole synthesis [80].
Conversion of amidine to 2-phenylbenzimidazole [86]. Reaction between 2-aminobenzyl alcohol and propiophenone [87]. Referred mechanism for reaction between 2-aminobenzyl alcohol and propiophenone [87]. Reaction between 1,2-phenylenediamine and acetone to form 2,3- dihydro-2,2,4-trimethyl-1H-1,5-benzodiazepine [88].
Proposed mechanism for reaction between 1,2-phenylenediamine and acetone catalyzed by MIL-100 (Fe) to form benzodiazepine [89]. Synthesis of 2-phenylquinazolin-4(3H)-one via a one-pot, two-step process [90]. Probable reaction mechanism [90]. Tandem process for the conversion of benzyl alcohol to 2- phenylquinazolin-4(3H)-ones [91].
Plausible reaction mechanism [91]. Reaction of benzyl alcohol and 2-aminobenzamide [92]. Plausible reaction mechanism [92]. Palladium-catalyzed alkoxylation of N-methoxybenzamides [103].
Copper-catalyzed phenoxylation of N-(quinolin-8-yl)benzamide derivatives [105]. Ullmann coupling of phenol derivatives and aryl halides catalyzed by MOF-199 [110]. Coupling reaction of nitroarenes and substituted phenols catalyzed by Cu2(BDC)2(DABCO) [111]. Reaction of 2-hydroxybenzaldehydes and dioxane catalyzed by Cu2(BPDC)2(BPY) [120].
Plausible reaction mechanism of dioxane and 2-hydroxybenzaldehyde [121]. Synthetic procedure of the Cu-MOF-74. Synthetic procedure of the Cu2(OBA)2(BPY). Synthetic procedure of the MOF-235.
Synthesis of 2-phenylbenzoxazole. Synthesis of 2-(4-nitrophenyl)quinazoline. Etherification of N-(quinolin-8-yl)benzamide with ethanol. Plausible reaction pathway.
Synthesis of 2-(4-nitrophenyl)quinazoline. Plausible reaction mechanism for the oxidative dehydrogenation reaction of 2-substituted 1,2-dihydro- 4H-3,1-benzoxazine. Reactions with large scale and the synthesis of targeted bioactive compounds. Plausible mechanism for alkoxylation of N-(quinolin-8-yl)benzamide.
84 LIST OF TABLES Table 1. Structure and characteristics of MOF-235, Cu2(OBA)2(BPY), Cu-MOF-74. Characteristics of synthesized Cu2(OBA)2(BPY), Cu-MOF-74 and MOF- 235. The synthesis of 2-arylbenzoxazoles and 2-arylbenzothiazoles via the one- pot oxidative cyclization reaction.
Scope of reactions. Reaction scope for alkoxylation and phenoxylation. 81 xii LIST OF ABBREVIATIONS Acac Acetylacetonate AQ Aminoquinoline CHP Cumyl hydroperoxide DEC Diethyl carbonate DTBP Di-tert-butyl peroxide BCMIM 1,3-Bis(carboxymethyl)imidazole BDC 1,4-Benzenedicarboxylate BET Brunauer–Emmett–Teller BPDC 4,4-Biphenyldicarboxylate BPY 4,4’-Bipyridine BTC 1,3,5-Benzenetricarboxylate CSD Cambridge Structural Database DABCO 1,4-Diazabicyclo [2.2] octane DCM Dichloromethane DMA N,N-Dimethylacetamide DMAP 4-Dimethylaminopyridine DMF N,N-Dimethylformamide DMSO Dimethyl sulfoxide GC Gas chromatography FT-IR Fourier Transform Infrared Spectroscopy FE-SEM Field emission scanning electron microscopy H2OBA 4,4’-Oxybis(benzoic)acid H2DHTP 2,5-Dihydroxyterephthalic acid H2BDC 1,4-Benzenedicarboxylic acid H2BPDC 4,4’-Biphenylcarboxylic acid HKUST Hong Kong University of Science and Technology IM Imidazole DMC Dimethyl carbonate xiii MIL Matériaux de I’Institut Lavoisier MS Mass Spectrometry NMR Nuclear Magnetic Resonance NMP N-Methyl-2-pyrrolidone NMO N-Methylpyrrolidine OAc Acetate OBA 4,4’-Oxybis(benzoate) Obz Benzoate PEG Polyethylene glycol PhI(OAc)2 Phenyliodine(III) diacetate P-XRD Powder X-ray Diffraction SBUs Secondary Building Units SEM Scanning Electron Microscopy VNU-18 Vietnam National University-Ho Chi Minh City TBHP tert-Butyl hydroperoxide TEA Triethanolamine TEM Transmission Electron Microscopy TGA Thermogravimetric Analysis TPA Terephthalic acid ZIF Zeolitic Imidazole Framework xiv INTRODUCTION Metal–organic frameworks (MOFs) have recently emerged as versatile materials in the field of heterogeneous catalysis due to their high surface area, modular nature and high crystallinity. MOFs have been used as catalysts for many carboncarbon, carbonheteroatom bond forming reactions.
Among molecules containing carbonheteroatom linkages, aryl ether compounds as well as compounds consisting of a five-membered or six-membered heterocyclic ring fused to benzene nucleus exhibit diverse biological properties.