chapter 2 palladium catalysts in suzuki cross- coupling reaction

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0.001% Pd, reaction of 1-bromonaphthalene was carried out at 0.005% Pd concentrations due to steric effect (compare entries 10, 11). 5.2.3. The Leaching Test for the Suzuki Reactions of Aryl Bromides The palladium leaching was investigated after the reaction. In view of the results obtained from the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analyses, Pd concentration of filtrate were found only
CHAPTER 6 CONCLUSIONS In this thesis study, Pd(NH3)4 2+ ion was easily loaded into the NaY zeolite. Activity of catalyst was investigated over Suzuki coupling reactions of aryl bromides and chlorides. The Pd(NH3)4 2+ -loaded NaY zeolite was observed to activate the C-Cl bond of the electron poor aryl chlorides in Suzuki reactions at low Pd concentrations in air within minutes. The excess amounts of zeolite provided the necessary water for the reaction when employed in as-received form. The results pointed out to a synergistic effect due to use of the water-zeolite pair for the reaction. The underlying reasons for the observed synergism seem to be complicated. However, the fact remains that the presence of little amount of water was crucial for the activation of the reaction system. In addition to water effect, the presence of excess amounts of zeolite in the reaction medium had important roles. We thought that it might have retarded the transformation of Pd to inactive Pd agglomerates during dissolution/re-precipitation processes on the zeolite surface and water from the zeolite will be released in a timely and localized manner (slowly) since it is in the pores, whereas water alone (without added zeolite) reacts in an uncontrolled way. Zeolite catalyst was also found highly active for Suzuki cross-coupling reactions of various bromoarenes with arylboronic acids without added ligands. The reactions were proceeded at very low Pd concentrations (0.01- 0.001% Pd). The presence of water was essential within the reaction medium. In both reactions of aryl chlorides and bromides, the catalyst was stable in air. The commercial source of phenylboronic acid reagent was found to be highly effective for the catalyst activity. Probably, variation types of impurities had different effects on the catalyst activity. It must also be noted that no dechlorination or self-coupling products were produced by the reactions performed under the established conditions. In the view of our results, the coupling reactions were seemed to be catalyzed by the dissolved Pd species leached from the Pd-NaY catalyst. On the other hand, ICP-MS 69
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SHORT-TIME SUZUKI REACTIONS OF ARYL
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ACKNOWLEDGEMENTS Firstly, I’d lik
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ÖZET ARİL HALOJENÜRLERİN HAVA A
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3.2.2. Catalysts Anchored to Inorga
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LIST OF FIGURES Figure Page Figure
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Figure A.27. 13 C NMR of 4-cyanobip
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CHAPTER 1 INTRODUCTION The palladiu
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CHAPTER 2 PALLADIUM CATALYSTS IN SU
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2.1.2. The Coordination Geometry of
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R 1 R 1 4. Sonogashira Reaction: H
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2.2.1. Mechanism of Suzuki Coupling
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As a result, organic group or hydri
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2.2.2.2. Halogen Effect Nearly all
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found to be excellent complexes for
Page 29 and 30: R Table 2.2. Examples from literatu
Page 31 and 32: L R Pd X R Pd L OR'' X L L + OR' R'
Page 33 and 34: omides and iodides is performed eff
Page 35 and 36: times for the transformation of a l
Page 37 and 38: R Br + (HO) 2B R' 5% Pd(OAc) 2 15%
Page 39 and 40: of insoluble solids are among the m
Page 41 and 42: could be reused multiple times. The
Page 43 and 44: 3.2.2. Catalysts Anchored to Inorga
Page 45 and 46: SO 2NH N Pd SO 2 N SO 2 NH NH H O1.
Page 47 and 48: utilized them in Heck and Suzuki co
Page 49 and 50: Smith et al introduced the use of P
Page 51 and 52: • Complexes immobilized in zeolit
Page 53 and 54: 3.3.3. Preparation of Zeolite-Suppo
Page 55 and 56: CHAPTER 4 EXPERIMENTAL STUDY 4.1. P
Page 57 and 58: temperature, the catalyst was recov
Page 59 and 60: amount of both reactant and product
Page 61 and 62: 4-Methoxybiphenyl: 1 H NMR (400 MHz
Page 63 and 64: 51 Table 4.1. Purification of coupl
Page 65 and 66: CHAPTER 5 RESULTS AND DISCUSSIONS I
Page 67 and 68: Table 5.2. The effect of base on Pd
Page 69 and 70: Table 5.4. The Optimization of Pd-N
Page 71 and 72: H 3COC Table 5.5. Effect of zeolite
Page 73 and 74: Table 5.6. Pd(NH3)4 2+ -loaded NaY
Page 75 and 76: The type of other organic co-solven
Page 77 and 78: yield was very low (Table 5.8, entr
Page 79: evealed excellent reactivity toward
Page 83 and 84: REFERENCES Albisson, D.A., Bedford,
Page 85 and 86: Choudary, B.M., Madhi, S., Chowdari
Page 87 and 88: Heiden, M. Plenio, H. 2004. ‘‘H
Page 89 and 90: Coupling Reactions of Aryl Chloride
Page 91 and 92: Phan, N.T.S., Brown, D.H., Styring,
Page 93 and 94: Wolfe, J.P., Singer, R.A., Yang, B.
Page 95 and 96: Figure A.1. 13 C NMR of 1-phenylnap
Page 97 and 98: Figure A.3. 13 C NMR of 2-acetylbip
Page 99 and 100: Figure A.5 . 13 C NMR of 2-methoxyb
Page 101 and 102: Figure A.7. 13 C NMR of 2-methylbip
Page 103 and 104: Figure A.9. 13 C NMR of 2-phenylnap
Page 105 and 106: Figure A.11. 13 C NMR of 3-acetylbi
Page 107 and 108: Figure A.13. 13 C NMR of 3-methoxyb
Page 109 and 110: Figure A.15. 13 C NMR of 3-phenylpy
Page 111 and 112: Figure A.17. 13 C NMR of 4-acetyl-4
Page 113 and 114: Figure A.19. 13 C NMR of 4-methoxyb
Page 115 and 116: Figure A.21. 13 C NMR of 4-methylbi
Page 117 and 118: Figure A.23. 13 C NMR of 4-phenylbe
Page 119 and 120: Figure A.25. 13 C NMR of 4-acetylbi
Page 121 and 122: Figure A.27. 13 C NMR of 4-cyanobip
Page 123 and 124: Figure A.29. 13 C NMR of 4-nitrobip
Page 125 and 126: Figure A.31. 13 C NMR of 4-phenylan
Page 127 and 128: APPENDIX B MASS SPECTRUMS OF SUZUKI
Page 129 and 130: Figure B.2. Mass spectrum of 2-acet
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Figure B.4. Mass spectrum of 2-meth
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Figure B.6. Mass spectrum of 3-acet
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Figure B.8. Mass spectrum of 3-phen
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Figure B.10. Mass spectrum of 4-phe
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Figure B.12. Mass spectrum of 4-met
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Figure B.14. Mass spectrum of 4-cya
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Figure B.16. Mass spectrum of 4-met
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