chapter 2 palladium catalysts in suzuki cross- coupling reaction

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Table 5.7. The Optimization of Pd-NaY catalyzed Suzuki reaction of 4-bromoanisole H 3CO over the Pd concentration of 0.005% a 4-Bromoanisole + Br Phenylboronic acid %0.005 mmol [Pd(NH3) 4] +2 B(OH) 2 -Y Base, Solvent, 100°C H 3CO 4-methoxybiphenyl Entry Base Solvent (Solvent/H2O) Conversion% b Yield% b 1 c,d Na2CO3 DMF(1/1) 75 71 2 c Na2CO3 DMF(1/1) 87 86 3 Cs2CO3 DMF(1/1) 52 52 4 K2CO3 DMF(1/1) 62 62 5 Na2CO3 NMP(1/1) 81 81 6 Na2CO3 DMA(1/1) 96 89 7 Na2CO3 DMA(1/2) 82 82 8 Na2CO3 DMA(1/3) 74 74 9 Na2CO3 DMA(2/1) 63 63 10 e Na2CO3 DMA(1/1) 94 94 11 e,f Na2CO3 DMA(1/1) 93 94 (92) g 12 f Na2CO3 DMA(1/1) 95 87 13 h Na2CO3 DMA(1/1) 96 91 a Typical reaction conditions: 10 mmol of 4-bromoanisole, 12 mmol of PhB(OH)2 (Fluka), 0.005% Pd, 20mmol Na2CO3 , 20ml Solvent/H2O, under inert atmosphere at 100 °C, 30min. b GC yield based on 4-bromoanisole. c 5 mmol 4-bromoanisole, 6mmol PhB(OH)2, 10mmol Na2CO3, 10ml DMF/water(1/1) was used. d PhB(OH)2 was supplied from Aldrich. e In the presence of zeolite (1g). f Open to the atmosphere. g Isolated yield. h PhB(OH)2 was supplied from Merck. We also tried to lower Pd concentration to 0.001% and performed reaction using the Merck reagent of phenylboronic acid under optimized conditions. However, the 64
yield was very low (Table 5.8, entry 1). The use of 2 or 3 g of zeolite has no effect on the reaction (Table 5.8, entries 2, 3). Nevertheless, presence of 4 g zeolite in the reaction medium decreased product formation (Table 5. 8, entry 4). We also increased amount of phenylboronic acid reagent to 2 mmol in the presence of 1g extra amount of zeolite. The catalyst could not show activity (entry 5). Reaction was repeated in the presence of NaOEt (entry 6). We increased reaction temperature to 130 ºC (entry 7). They didn’t work. Finally, moderate yield was obtained by using Fluka reagent (Table 5.8, entry 8). We concluded that Pd concentration of 0.005% was optimum in the presence of 1g of zeolite and Fluka reagent for Suzuki reactions of 4-bromoanisole. Table 5.8. The Optimization of Pd-NaY catalyzed Suzuki reaction of 4-bromoanisole over the Pd concentration of 0.001 % a Entry Zeolite (g) Ratio of PhB(OH)2 Conversion% b Yield% b 1 1 1.2 49 33 2 2 1.2 55 33 3 3 1.2 68 31 4 4 1.2 18 18 5 1 2 20 14 6 c 1 1.2 25 8 7 d 1 1.2 41 14 8 e 1 1.2 78 61 a Reaction conditions: 5mmol 4-bromoanisole, 6mmol PhB(OH)2 (Merck), 10mmol Na2CO3, 10mL DMA: water (1:1) under air at 100 ºC. b GC yield. c NaOEt was used as base. d at 130 ºC. e PhB(OH)2 was supplied from Fluka and amount of all reagents was increased by two. 5.2.2. Pd(NH3)4 2+ -Loaded NaY Type Zeolite Catalyzed Suzuki Reactions of Aryl Bromides and ArylBoronic Acids After optimization of reaction conditions, we investigated the substrate scope of the reaction for a range of aryl bromides with PhB(OH)2 (Table 5.9). 65
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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
Page 15 and 16:
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
Page 25 and 26: 2.2.2.2. Halogen Effect Nearly all
Page 27 and 28: 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: The type of other organic co-solven
Page 79 and 80: evealed excellent reactivity toward
Page 81 and 82: CHAPTER 6 CONCLUSIONS In this thesi
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
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APPENDIX B MASS SPECTRUMS OF SUZUKI
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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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chapter 2 palladium catalysts in suzuki cross- coupling reaction

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