Metal Promoted Selectivity in Organic Synthesis

ISBN-13: 9780792311843 / Angielski / Twarda / 1991 / 373 str.

A. Noels; M. Graziani; A. J. Hubert

Opis

The demand for selective organic reactions is growing more acute everyday. Indeed, greater product selectivity has an important impact on energy and resource utilization, in terms of reduced process energy requirements for product separation and purification, in terms of low-value by-products, and in terms of environmental acceptance and compatibility. Moreover, more and more chemicals, especially pharmaceuticals, have to be sold in an optically active form. The search for selectivity constitutes a tremendous challenge for the chemists. In the last two decades, homogeneous transition metal based catalysis has emerged as one of the most promising tools for obtaining selectivity. In connection with developments in this area, this book contains updated and expanded versions of most of the lectures presented at a Cornett course held in Trieste (Italy) in 1989 and sponsored by the European Community. A primary aim is to cultivate a deeper understanding of the parameters that govern the selectivities and stimulate a wider utilization of transition metal based catalysis in organic synthesis. All aspects of selectivity, chemo-, regio-, stereo- and enantioselectivity are considered and illustrated by applications in various fields or organic synthesis. The impact of catalysis in oxydation, reduction, carbonylation reactions, carbene chemistry, in Ni and Pd promoted dimerizations, oligomerizations as well as fonctionalisations is stressed, quite often with special emphasis laid on reaction mechanisms. In this aspect, the last chapter examplifies the interest of high pressure NMR and IR when investigating the nature of reaction intermediates in homogeneous reactions.

Recenzje

`This book can be recommended to advanced chemistry students as well as researchers wishing to obtain information on industrial applications of homogeneous catalysis by transition metal complexes.'
React. Kinet. Catal. Lett. 48:1 (1992)

Spis treści

Industrial Aspects of Selectivity Applying Homogeneous Catalysis.- 1. Contributions of homogeneous catalysis to selectivity.- 1.1. Chemoselectivity.- 1.2. Regioselectivity.- 1.3. Stereoselectivity.- 1.4 Shapeselectivity.- 2. Selectivity and homogeneous, industrial processes.- 2.1. Optimal utilization of starting materials.- 2.2. Avoidance of by-products.- References.- To which Extent do Phosphanes Induce Selectivity in C?C Bond Formation?.- 1. Introduction.- 2. Structural, physical and bonding properties of phosphanes.- 2.1. The steric parameter ?: the cone angle.- 2.2. The electronic parameters.- 2.3. Bonding of phosphorus (III) ligands.- 2.3.1. Basicity of phosphines and ó-bonding.- 2.3.2. ?-Bonding.- 2.3.3. Separation of ?- and ?-bonding components.- 3. Oligomerisation of alkenes.- 3.1. Oligomerisation of ethylene.- 3.2. Oligomerisation of terminal alkenes.- 3.2.1. Propene.- 3.2.2. Styrene.- 3.2.3. Dimerisation of acrylates.- 4. Oligomerisation of butadiene.- 4.1. Influence of phosphanes on product distribution.- 4.2. Structure — selectivity relationships.- 4.3. Preparation of higher oligomers.- 5. Hydroformylation of alkenes.- 5.1. Tertiary-phosphine modified cobalt carbonyl systems.- 5.2. Tertiary-phosphine modified rhodium complexes.- 5.3. Two-phase hydroformylation.- 6. Conclusion.- References.- Ligand Controlled Catalysis: Chemo to Stereoselective Syntheses from Olefins and Dienes over Nickel Catalysts.- 1. Diene-olefin codimerization.- 1.1. Chemo and regioselective butadiene-ethylene codimerization.- 1.2. Butadiene-functionalized olefin codimerization.- 1.3. Asymmetric diene-olefin codimerization.- 1.3.1. Scope of the reaction.- 1.3.2. Aminophosphinephosphinites chelating ligands for cyclohexadiene-ethylene codimerization.- 2. Cyclodimerization of dienes.- 2.1. Scope of the reaction.- 2.2. Substituted conjugated dienes.- 2.3. Enantioselective cyclodimerizations.- 3. Linear dimerization of dienes.- 3.1. Linear dimerization of butadiene.- 3.2. Linear dimerization of alkyl substituted and functionalized dienes.- 3.3. Linear dimerization on nickel aminophosphinite complexes.- 3.3.1. Butadiene dimerization.- 3.3.2. Labelled experiments.- 3.3.3. Substituted dienes.- 3.3.4. Functionalized dienes.- 4. Concluding remarks.- References.- Catalytic Activation of Hydrogen Peroxide in Selective Oxidation Reactions.- 1. Introduction.- 2. General discussion on the activation of hydrogen peroxide.- 2.1. Homolytic decomposition.- 2.2. Heterolytic decomposition.- 2.2.1. Natural activation.- 2.2.2. Catalytic activation.- 3. Practical applications.- 3.1. Oxidation of ketones to esters or lactones.- 3.2. Olefin epoxidation.- 3.3. Amines oxidation.- 3.3.1. Aromatic amines.- 3.3.2. Alipathic secondary amines.- 4. Conclusion and safety rules.- Acknowledgements.- References.- Enantioselective S-Oxidation: Synthetic Applications.- References.- Mechanisms in Stereo-Differentiating Metal-Catalyzed Reactions. Enantioselective Palladium-Catalyzed Allylation.- 1. The palladium-catalyzed substitution of allylic substrates by nucleophiles. The reaction. The catalytic steps.- 1.1. The ?3-allylpalladium forming steps (oxidative addition of the substrate to a palladium (0) complex). The reactive allylic compounds.- 1.2. The nucleophilic attack step. The active nucleophiles.- 2. The stereochemical course of the reaction; analysis of the stereochemistry of each individual catalytic step.- 2.1. The ?3-allyl forming step is under stereoelectronic control; stereochemical requirements for the allylic substrate to be reactive.- 2.2. The use of properly devised models to appreciate the way of attack of the nucleophile.- 3. Enantioselective synthesis. Asymmetric induction.- 3.1. Optically active substrates the chiral director is located in the substrate.- 3.1.1. As the leaving group.- 3.1.2. In the allylic frame.- 3.2. Optically active nucleophiles. The chiral inducer is located in the nucleophile.- 3.3. Optically active catalysts. The chiral inducer is located in the ligand of the catalyst.- 3.3.1. The substrate is achiral, non-prochiral; the nucleophile is prochiral.- 3.3.2. The substrate is prochiral, chiral or achiral; the nucleophile is not prochiral.- References.- Regio-, Stereo-, and Enantioselectivity in Palladium and Platinum Catalyzed Organic Reactions.- 1. Introduction.- 2. Rearrangements.- 3. 1,4-Difunctionalization of 1,3-dienes.- 4. Cyclisation of non-conjugated dienes.- 4.1. Organopalladation of non-conjugated dienes.- 4.2. Ene reaction of dienes and olefins coupling reactions.- 5. Asymmetric alkylation via ?-allyl Pd complexes.- 6. Asymmetric hydroformylation.- References.- Asymmetric Hydrogenation.- 1. Introduction.- 2. General principles.- 2.1. Chiral phosphine ligands.- 2.2. Structure of the substrates.- 2.3. Stereochemistry of the hydrogenations.- 2.4. Mechanism of the hydrogenations with rhodium (I)- and iridium (I)-catalysts.- 2.4.1. Hydrogenation of substrates with directing groups.- 2.4.2. Hydrogenation of substrates without directing groups.- 2.5. Hydrogenations with ruthenium-catalysts.- 3. Asymmetric hydrogenation of substituted olefins.- 3.1. Amino acid precursors.- 3.2. (Z)-enamides.- 3.3. Unsaturated carboxylic acid derivatives.- 3.4. ?,?-unsaturated aldehydes and ketones.- 3.5. Allylic and homoallylic alchohols.- 4. Asymmetric hydrogenation of carbon-oxygen double-bonds.- 4.1. ?-ketoachid derivatives.- 4.2. Hydrogenation of ?-keto compounds.- 4.3. Alkylamino aryl ketones.- 4.4. Ketones.- 5. Asymmetric hydrogenation of carbon-nitrogen double-bonds.- References.- The Design of a Chemoselective Reduction Catalyst.- 1. Introduction.- 2. Reduction of ?, ?-unsaturated ketones.- 2.1. Hydrogenation reactions.- 2.1.1. Hydrogenation with iridium/monophosphine systems.- 2.1.2. Hydrogenation with iridium/diphosphine systems.- 2.1.3. Hydrogenation with iridium/P?N systems.- 2.2. Hydrogen transfer reactions: catalysis by iridium/P?N systems.- 3. Conclusions.- Acknowledgements.- References.- Palladium Catalyzed Reduction of Aryl Sulfonates Selectivity Control and Application to Anthracycline Chemistry.- References.- Selective Stoichiometric Reductions of Organic Functional Groups by Aqueous Metal Ions. Implications to Synthesis and Catalysis.- References.- Basic Principles in Carbene Chemistry and Applications to Organic Synthesis.- 1. Introduction.- 2. Basic principles of carbene reactivity.- 3. Methods for generating carbenes.- 4. Transition-metal-promoted carbene reactions.- 4.1. Recations of carbenoids.- 4.1.1. The catalytic cycle.- 4.1.2. Factors governing the catalytic activity.- 4.1.3. Typical catalysts.- 4.1.4. Typical ligands.- 4.2. Selectivities in catalysed carbene reactions.- 4.2.1. Stereo selectivity.- 4.2.1.1. Enantioselectivity.- 4.2.1.2. Cis to trans selectivity.- 4.2.2. Regioselectivity and discrimination between different substrates and functions.- a. Regioselectivity.- b. Discrimination.- c Competition.- d. Regioselectivity and discrimination in the Büchner’s reaction.- e. Discrimination between different functionalities: chemo-selectivity.- 5. Applications.- 6. References.- Carbonylchromium (O) Complexes in Organic Synthesis.- 1. Arenetricarbonylchromium complexes.- 1.1. Methods of preparation and decomplexation.- 1.2. Effects of coordination of arenes to Cr(CO)3.- 1.3. Stabilization of benzylic carbanion.- 1.4. Metallation of the complexed arenas.- 1.5. Nucleophilic attack on ?6-arene Cr(CO)3 complexes.- 1.6. Asymmetric chromiumtricarbonyl arene derivatives.- 2. Pentacarbonylcarbene chromium complexes.- 2.1. Synthesis of carbene complexes.- 2.2. Reactivity of carbene complexes.- References.- Role and Implications of H+ and H? Anionic Hydrido Carbonyl Catalysts on Activity and Selectivity of Carbonylation Reactions of Unsaturated and Oxygenated Substrates.- 1. Hydroformylation of olefins.- 2. Hydrocarbonylation of oxygenated substrates with ruthenium catalysts.- 3. Hydrogenation of carbon monoxide.- Acknowledgements.- References.- Catalytic Carbonylations of Nitrogen Containing Organic Compounds.- 1. Introduction.- 2. Carbonylation of organic azides.- 3. Carbonylation of aromatic nitro compounds.- 4. Oxidative carbonylation of amines.- 5. Conclusions.- References.- Applications of Spectroscopic Measurements to Homogeneous Catalysis.- 1. Catalytic hydrogenation of alkenes.- 1.1. Preamble.- 1.2. Application of NMR spectroscopy in determining chemical exchange.- 1.3. Ligand exchange in [RhCl(PPh3)3].- 1.4. Ligand exchange in [RhH2Cl(PPh3)3].- 1.5. Reversibility of H2 uptake in oxidative-addition reactions determined via para-hydrogen induced polarization.- 2. Rhodium catalysed asymmetric hydrogenation.- 2.1. Mechanism of interconversion of the diastereoisomeric complexes (12) and (12?).- 2.2. Stereochemistry of the hydrogenated intermediates.- 3. Spectroscopic measurements under high pressure of gas.- 3.1. IR (HPIR).- 3.2. NMR (HPNMR).- 4. HPIR and HPNMR study of the reactions of [Rh4(CO)12?xLx], (x = 1 to 4; L = P3) with CO, H2 or syngas.- 4.1. Introduction.- 4.2. Reaction of [Rh4(CO)8{P(OPh)3}4] with CO.- 4.3. Reaction of [Rh4(CO)11 {P(OPh)3}] with CO.- 4.4. Reaction of [Rh4(CO)9{P(OPh)3}3] with CO.- 4.5. Fluxionality in [Rh2(CO)6{P(OPh)3}2] and [Rh2(CO)7{P(OPh)3}].- 5. Conclusions.- Acknowledgements.- References.