Oxidative carbonylation of alkanols catalyzed by Pd(II)-phosphine complexes

dc.contributor.advisor	Toniolo, Luigi	it_IT
dc.contributor.author	Amadio, Emanuele <1981>	it_IT
dc.date.accessioned	2010-03-27T07:29:25Z	it_IT
dc.date.accessioned	2012-07-30T15:50:52Z
dc.date.available	2013-11-04T10:32:21Z
dc.date.issued	2010-03-15	it_IT
dc.identifier.uri	http://hdl.handle.net/10579/946	it_IT
dc.description.abstract	The complexes trans–[Pd(COOR)(H2O)(PPh3)2](TsO) (R = Me, Et, nPr, iPr, nBu, iBu, secBu) and trans–[Pd(COOR)nX2–n(PPh3)] (R = Me, n = 1, 2; X = ONO2, ONO, OTs, Br. R = iPr, n = 1, X = Cl, Br) have been synthesised and characterised. Most of them have been used as catalyst precursors for the oxidative carbonylation of MeOH, selective to dimethyloxalate, using p–benzoquinone (BQ) as an oxidant. BQ changes properties of the reaction centre. When using iPrOH in place of MeOH, high activity and selectivity toward diisopropyloxalate have been achieved using trans–[PdX2(PAr3)2] with strongly coordinating X (Br), in presence of a base (NEt3 or PAr3–BQ adduct) and of an excess of LiBr. The slow step of the catalysis (RDS) might be the reoxidation of Pd(0), which is formed in the product–forming step. Using [PdX2(P-P)] the best performance has been achieved with weakly coordinating X (TsO) and using P-P of relatively wide bite angle but with cis–geometry. The RDS is related to the nature of P-P.	it_IT
dc.description.abstract	Sono stati sintetizzati e caratterizzati i complessi trans–[Pd(COOR)(H2O)(PPh3)2](TsO) (R = Me, Et, nPr, iPr, nBu, iBu, secBu) e trans–[Pd(COOR)nX2–n(PPh3)] (R = Me, n = 1, 2; X = ONO2, ONO, OTs, Br. R = iPr, n = 1, X = Cl, Br). Molti sono stati utilizzati come precursori catalitici nella carbonilazione ossidativa di MeOH, selettiva a dimetiloxalato, impiegando p–benzochinone (BQ) come ossidante. Il BQ modifica le proprietà del centro di reazione. Con iPrOH al posto di MeOH si ottengono elevate attività e selettività a diisopropyloxalato utilizzando trans–[PdX2(PAr3)2] con X fortemente coordinanti (Br), in presenza di base (NEt3 o PAr3–BQ) e di LiBr in eccesso. Lo stadio lento della catalisi (RDS) potrebbe essere la riossidazione del Pd(0) che si forma nello stadio di formazione dell’ossalato. Con [PdX2(P-P)] le migliori prestazioni sono state ottenute con X debolmente coordinanti (TsO) e con P-P ad angolo di morso relativamente ampio ma di geometria cis. L’ RDS dipende da P-P.	it_IT
dc.format.medium	Tesi cartacea	it_IT
dc.language.iso	en	it_IT
dc.publisher	Università Ca' Foscari Venezia	it_IT
dc.rights	© Emanuele Amadio, 2010	it_IT
dc.subject	Oxidative carbonylation	it_IT
dc.subject	Palladium	it_IT
dc.subject	Phosphine	it_IT
dc.subject	Carbonylation	it_IT
dc.subject	Alkanol	it_IT
dc.title	Oxidative carbonylation of alkanols catalyzed by Pd(II)-phosphine complexes	it_IT
dc.type	Doctoral Thesis	it_IT
dc.degree.name	Scienze chimiche	it_IT
dc.degree.level	Dottorato di ricerca	it_IT
dc.degree.grantor	Facoltà di Scienze matematiche fisiche e naturali	it_IT
dc.description.academicyear	2008/2009	it_IT
dc.description.cycle	22	it_IT
dc.degree.coordinator	Ugo, Paolo	it_IT
dc.location.shelfmark	D000877	it_IT
dc.location	Venezia, Archivio Università Ca' Foscari, Tesi Dottorato	it_IT
dc.rights.accessrights	openAccess	it_IT
dc.thesis.matricno	955382	it_IT
dc.format.pagenumber	V, 188 p.	it_IT
dc.subject.miur	CHIM/04 CHIMICA INDUSTRIALE	it_IT
dc.description.note	Doctor Europaeus	it_IT
dc.description.tableofcontent	GENERAL INTRODUCTION 1 PREFACE 1 Oxidative carbonylation of alkanols 6 General aspects. 6 Industrial production of oxalates using alkyl nitrites as oxidant. 7 Other oxidative reactions using p–benzoquinone 11 Oxidative carbonylation of styrene. 11 1,4 Dialkoxylation of conjugated dienes. 14 Oxidation of ethene to acetaldehyde (Wacker process). 15 SCOPE AND CONTENTS OF THE THESIS 17 REFERENCES 18 CHAPTER 1 21 INTRODUCTION 21 RESULTS AND DISCUSSION 23 Synthesis and characterization of the carboalkoxy complexes reported in Table 1 23 X–ray structure analysis of [Pd(COOMe)(TsO)(PPh3)2]•2 CHCl3 (IIa) 27 Reactivity 31 Reactivity with alkanols. 31 Reactivity with acids HX (X = Cl, OAc, TsO). 32 Reactivity with water and with water/TsOH. 32 Reactivity with ethene and catalytic properties of complexes (Ia–g) in the hydrocarboalkoxylation of ethene. 33 CONCLUSIONS 38 EXPERIMENTAL SECTION 39 Instrumentation and Materials 39 Preparation of the Complexes 39 Synthesis of trans–[Pd(COOR)(H2O)(PPh3)2](TsO) (R = Me, Et). 39 Synthesis of trans–[Pd(COOR)(H2O)(PPh3)2](TsO) with R bulkier than Et. 39 Reactivity tests 40 Experiments of hydroesterification of ethene using the carboalcoxy complexes reported in Table 1 as catalyst precursors in the relevant ROH 40 X–ray data collection, structure solution and refinement 41 REFERENCES 42 CHAPTER 2 48 INTRODUCTION 48 RESULTS AND DISCUSSION 50 Synthesis and characterization of I, Ia, II, III and IIIa 50 Reactivity and catalytic properties of I, Ia, II, III, and IIIa 59 Structural Characterization of Ia and of I.CH2Cl2 65 CONCLUSIONS 74 EXPERIMENTAL SECTION 75 Instrumentation and Materials 75 Preparation of the Complexes 76 Synthesis of cis–[Pd(ONO2)2(PPh3)2] (I). 76 Synthesis of trans–[Pd(COOMe)(ONO2)(PPh3)2] (Ia). 76 Synthesis of trans–[Pd(COOMe)2(PPh3)2] (II). 77 Synthesis of [Pd(ONO)2(PPh3)2] (III). 78 Synthesis of trans–[Pd(COOMe)(ONO)(PPh3)2] (IIIa). 78 Synthesis of cis–[Pd(C2O4)(PPh3)2] (IV). 79 Reactivity tests 80 X–ray Structure Determinations 80 REFERENCES 82 CHAPTER 3 86 INTRODUCTION 86 RESULTS AND DISCUSSION 88 NMR investigations on the reactivity of I, II and III 88 Reactivity of I. 90 Reactivity of II. 103 Reactivity of III. 108 Catalytic oxidative carbonylation of methanol using I, II and III 115 On the catalytic cycle of the oxidative carbonylation reaction of alcohols 117 CONCLUSIONS 121 EXPERIMENTAL 121 Instrumentation and Materials 121 Preparation of the Complexes 122 Synthesis of trans–[Pd(COOMe)2(PPh3)2] (II). 122 Synthesis of [Pd(COOMe)(PPh3)3](TsO). 122 High pressure NMR experiments 122 REFERENCES 124 CHAPTER 4 126 INTRODUCTION 126 RESULTS AND DISCUSSION 127 Influence of counter anion on the activity and selectivity of [PdX2(PPh3)2] 127 Effect of promoters on the activity and selectivity of [PdX2(PPh3)2] 128 Effect of NEt3. 128 Effect of added halides. 129 Influence of added PPh3. 131 Effect of operative conditions on the activity and selectivity of trans–[PdBr2(PPh3)2] 132 Effect of reaction time and of BQ. 132 Effect of temperature. 133 Effect of the pressure of CO. 134 Electronic and steric effects of the phosphine ligands 134 On the catalytic cycle of the oxidative carbonylation of iPrOH 136 On the coordination of L to the palladium centre during catalysis. 136 Product forming step and attempted reformation of the precursor. 141 Reactivity with LiBr. 144 Proposed catalytic cycle. 146 CONCLUSIONS 147 EXPERIMENTAL SECTION 148 Instrumentation and Materials 148 Preparation of the Complexes 148 Synthesis of [PdCl2L2] (L = (zY–C6H4)3P (z = o, m, p; Y= CH3, CH3O, F); [o,o’(CH3O)2(C6H3)]3P). 148 Synthesis of [PdBr2L2] (L = PPh3, (zY–C6H4)3P (z = o, m, p; Y= CH3, MeO, F), [o,o’(MeO)2(C6H3)]3P). 149 Synthesis of cis–[Pd(SO4)(PPh3)2]. 150 Synthesis of trans–[PdBr(COOiPr)(PPh3)2]. 150 Synthesis of H2BQ–BQ adduct 150 Catalytic Oxidative Carbonylation of iPrOH 152 Reactivity of trans–[PdBr2(PPh3)2] in oxidative carbonylation conditions 152 High pressure NMR experiments 153 REFERENCES 154 CHAPTER 5 156 INTRODUCTION 156 RESULTS AND DISCUSSION 157 Influence of the anion of the catalyst precursor [PdX2(dppf)] (dppf = 1,1’–bis(diphenylphosphino)ferrocene 157 Effect of the pressure of carbon monoxide 159 Influence of the natural bite angle of the diphosphine ligands 161 Electronic and steric effects of the diphosphine ligand 166 Reactivity of [Pd(COOR)2(P-P)] 169 CONCLUSIONS 173 EXPERIMENTAL SECTION 174 Instrumentation and Materials 174 Catalytic Oxidative Carbonylation of iPrOH 175 Ligand synthesis 175 Synthesis of pCF3–dppf. 175 Complex synthesis 176 Synthesis of cis–[Pd(OAc)2(P-P)] (P-P = dppe, dppb, dppf, dippf, dtbpf, dcypf, pCF3–dppf, DPEphos, Xantphos). 176 Synthesis of [PdCl2(P-P)] (P-P = pCF3–dppf, pMeO–dppf, SPANphos) 177 Synthesis of [Pd(OH2)n(OTs)2–n(P-P)](TsO)n (n = 0, 1; P-P = dppe, dppb, dppf, dippf, dtbpf, dcypf, pCF3–dppf, DPEphos, Xantphos, pMeO–dppf, SPANphos). 178 Synthesis of cis–[Pd(C2O4)(dppf)]. 180 Synthesis of cis–[Pd(SO4)(dppf)]•H2O. 180 Synthesis of cis–[Pd(COOMe)2(P-P)] (P-P = dppe, dppp). 180 Synthesis of trans–[Pd(COOMe)(OTs)(SPANphos)]. 181 In situ NMR study on the preparation of [Pd(COOMe)2(P-P)] (P-P = dppe, dppp, dppb, dppf, DPEphos, Xantphos, SPANphos) by exchange reaction. 181 REFERENCES 185 SHORT FINAL COMMENT 188 ABSTRACT/RIASSUNTO 189	it_IT
dc.identifier.bibliographiccitation	Amadio, Emanuele. "Oxidative carbonylation of alkanols catalyzed by Pd(II)-phosphine complexes", Ca' Foscari University Venice, 22. cycle, 2010	it_IT