3 research outputs found
감마-알루미나에 고정시킨 팔라듐-질소헤테로고리카벤 촉매를 이용한 스즈키-미야우라 짝지음 반응에 대한 연구
학위논문 (석사)-- 서울대학교 대학원 : 화학생물공학부, 2017. 2. 이윤식.ABSTRACT
Preparation of Pd-NHC Catalyst Immobilized on γ-Alumina for Suzuki-Miyaura Cross-Coupling Reaction
Min-Ki Kang
School of Chemical and Biological Engineering
The Graduate School
Seoul National University
γ-Alumina (γ-aluminium oxide) supported palladium(II)-N-heterocyclic carbene (Pd-NHC) complex is one of the effective Suzuki-Miyaura cross-coupling catalysts in water dominant environment. NHCs are stable ligands in aqueous conditions, and they have been used for spectator ligands of Suzuki-Miyaura cross-coupling catalyst. γ-Alumina is one of the suitable solid supports due to its hydrophilicity and large surface area but has not been fully studied for Suzuki-Miyaura reaction. In this research, two kinds of 1-substituted imidazoles were synthesized as precursors of NHCs, and Pd-NHC complexes were prepared by using Pd(OAc)2 and these precursors. Finally, the catalysts were prepared by immobilizing the Pd-NHC complexes on γ-alumina. The catalysts were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron mictrscope (SEM), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The catalytic activity was investigated under various solvents and basic conditions via conventional heating or microwave heating methods. As a result, up to 99% yields were obtained from the reactions of aryl bromides with phenylboronic acid at 50℃ for 2 h.I. Introduction 1
I. 1. Suzuki-Miyaura Reaction in Water 2
I. 2. Pd-NHC Complex in Suzuki-Miyaura Reaction 3
I. 3. Heterogenous Pd-NHC Suzuki-Miyaura Catalyst 5
I. 4. γ-Alumina as a Catalyst Support 6
I. 5. Microwave-Assisted Suzuki-Miyaura Reaction 7
I. 6. Research Objectives 8
II. Experimental Section 9
II. 1. General 10
II. 1. 1. Materials 10
II. 1. 2. Instruments 10
II. 2. Preparation of γ-Alumina Supported Pd-NHC 12
II. 2. 1. Synthesis of 1-Substituted Imidazoles 12
II. 2. 2. Preparation of 3-(Iodopropyl)triethoxysilane 14
II. 2. 3. Preparation of NHC precursors 15
II. 2. 4. Immobilization of Pd-NHC Complex on γ-Alumina 18
II. 3. Suzuki-Miyaura Reaction Catalyzed by γ-Alumina Supported Pd-NHC 21
II. 3. 1. General Experimental Procedure for Suzuki-Miyaura Reaction 21
II. 3. 2. Optimization of Suzuki-Miyaura Reaction in Various Solvents and Bases 22
II. 3. 3. Determination of Reaction Kinetics 23
II. 3. 4. Reaction Profiles at Various Temperature by using Microwave as Heating Method 24
II. 3. 5. Reusability of γ-Alumina Supported Pd-NHC 25
III. Results and Discussion 26
III. 1. Preparation and Characterization of γ-Alumina Supported Pd-NHC 27
III. 1. 1. Preparation of γ-Alumina Supported Pd-NHC 27
III. 1. 2. Characterization of γ-Alumina Supported Pd-NHC 30
III. 2. Suzuki-Miyaura Reaction Catalyzed by γ-Alumina Supported Pd-NHC 36
III. 2. 1. Effects of Solvents and Bases in Suzuki-Miyaura Reaction 36
III. 2. 2. Reaction Profiles of Suzuki-Miyaura Reaction 46
III. 2. 3. Suzuki-Miyaura Reaction of Various Aryl Halides with Phenylboronic acid 51
III. 2. 4. Reusability of γ-Alumina Supported Pd-NHC for Suzuki-Miyaura Reaction 54
IV. Conclusion 59
References 61
국문 초록 67
Appendix 68Maste