chapter 2 palladium catalysts in suzuki cross- coupling reaction

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solubilize many organometallic compounds. These properties, in addition to its controllable miscibility with water and immiscibility with ether, make [bmim][BF4] a potential solvent for Suzuki reactions (Mathews et al. 2000). Mathews et al. have demonstrated that Suzuki cross-coupling reactions of electron-rich and electron-deficient aryl bromides with arylboronic acids and their derivatives can be successfully conducted in 19 and at ambient temperature (Mathews et al. 2000). Cl + H3P - F F B - F N + F 19 20 N Figure 3.4. Ionic liquid types used in the Suzuki reactions (Source: McNulty et al. 2002, Mathews et. al 2000) The Suzuki cross-coupling reactions of aryl chlorides with arylboronic acids were also achieved in a phosphonium salt ionic liquid, tetradecylphosphonium chloride, 20 (Figure 3.4), in 1,3-di-n-butylimidazolium tetrafluoroborate [bbim][BF4] in the presence of K3PO4 and a catalytic amount of Pd2(dba)3, as well as in the ionic liquid (McNulty et al. 2002). 3.2. The Immobilization to Insoluble Support One another general strategy to transform a homogeneous catalyst into a heterogeneous catalyst is to anchor the active site onto an insoluble support. Two types 26
of insoluble solids are among the most useful supports to anchor complex catalyst, inorganic solids and polymers (Baleizao et al. 2003, Baleizao et al. 2004). 3.2.1. Attachment to Polymer Supports Polymers present a high hydrophobicity that makes them suitable for reactions in organic (Baleizao et al. 2003, Baleizao et al. 2004). Attachment of catalytic groups to the polymer support can be achieved by well-known organic and organometallic synthesis (Smith and Nontheisz 1999). method. In the literature, there have been many heterogeneous catalysts prepared by this The amphiphilic poly(ethyleneglycol)-polystyrene resin-supported palladium- monophosphine complex, 21 (Figure 3.5), was found to be active catalyst in the reaction of aryl halides and allyl acetates with aryl boron compounds in aqueous media (Table 3.1, entry 1). This catalyst could be easily removed from the reaction mixture and reused with no decrease in activity (Uozumi et al. 1999). In another study, the Merrifield resin-supported salen-type palladium catalyst, 22 (Figure 3.5), prepared was found to be effective recyclable heterogeneous catalyst for the Suzuki cross-coupling reaction without the use of ligands. The Suzuki reactions were performed with activated aryl bromides in the presence of 0.5mol% Pd resin catalyst (Table 3.1, entry 2). The supported precatalyst was found to be significantly more useful than the corresponding homogeneous analogue (Phan et al. 2004). An assembled complex of palladium and a non cross-linked amphiphilic polymer, denoted as PdAS, was prepared from (NH4)2PdCl4 and non-cross-linked amphiphilic polymer poly[(N-isopropylacrylamide)-co-(4-diphenylstyrylphosphine)], 23 (Figure 3.5). The material was found to be an excellent catalyst precursor for heterogeneous Suzuki reactions of aryl and alkenyl halides and benzylic chlorides with arylboronic and alkenyl boronic acids and alkyl-9-borabicyclo[3.3.1]nonanes with high turnover numbers, PdAS was reused 10 times without any decrease in its catalytic activity (Yamada et al. 2003). 27
Page 1 and 2: SHORT-TIME SUZUKI REACTIONS OF ARYL
Page 3 and 4: ACKNOWLEDGEMENTS Firstly, I’d lik
Page 5 and 6: ÖZET ARİL HALOJENÜRLERİN HAVA A
Page 7 and 8: 3.2.2. Catalysts Anchored to Inorga
Page 9 and 10: LIST OF FIGURES Figure Page Figure
Page 11 and 12: Figure A.27. 13 C NMR of 4-cyanobip
Page 13 and 14: CHAPTER 1 INTRODUCTION The palladiu
Page 15 and 16: CHAPTER 2 PALLADIUM CATALYSTS IN SU
Page 17 and 18: 2.1.2. The Coordination Geometry of
Page 19 and 20: R 1 R 1 4. Sonogashira Reaction: H
Page 21 and 22: 2.2.1. Mechanism of Suzuki Coupling
Page 23 and 24: 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: R Br + (HO) 2B R' 5% Pd(OAc) 2 15%
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 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
Page 127 and 128:
APPENDIX B MASS SPECTRUMS OF SUZUKI
Page 129 and 130:
Figure B.2. Mass spectrum of 2-acet
Page 131 and 132:
Figure B.4. Mass spectrum of 2-meth
Page 133 and 134:
Figure B.6. Mass spectrum of 3-acet
Page 135 and 136:
Figure B.8. Mass spectrum of 3-phen
Page 137 and 138:
Figure B.10. Mass spectrum of 4-phe
Page 139 and 140:
Figure B.12. Mass spectrum of 4-met
Page 141 and 142:
Figure B.14. Mass spectrum of 4-cya
Page 143:
Figure B.16. Mass spectrum of 4-met
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