Concurrent tandem catalysis

Abstract: The reaction of olefins with carbon monoxide and hydrogen to give aldehydes is referred to as hydroformylation (oxo reaction). As catalyst for this reaction rhodium is about three to four orders of magnitude more active than the more commonly employed cobalt. With special rhodium compounds, e.g. di-ν-chlorobis(ν-1,5-cyclooctadiene)dirhodium [RhCl(C8H12)]2, in the presence of chiral phosphanes, even asymmetric hydroformylations can be achieved; however, the enantiomeric purity of the products (20–30%) is not high enough for industrial-scale syntheses.

Abstract: Preface INTRODUCTION The Beginnings of Catalytic Research The Catalysis Definitions of Berzelius and Ostwald PRINCIPLES OF ORGANOMETALLIC CATALYSIS Homogeneous versus Heterogeneous Catalysis Catalytic Cycles Activity and Productivity of Catalysts Selectivity and Specificity of Catalysts Determination of Catalytic Mechanisms Glossary for Catalysis The Development of Organometallic Catalysis ELEMENTARY STEPS IN ORGANOMETALLIC CATALYSIS Cleavage and Coordination of Ligands Oxidative Addition and Reductive Elimination Oxidative Coupling and Reductive Cleavage Olefin Insertion and Beta-Hydrogen Elimination Alpha-Hydrogen Elimination and Carbene Insertion Reactions Addition of Nucleophiles and Heterolytic Fragmentation Insertion and Extrusion of CO One-Electron Reduction and Oxidation HYDROGENATION OF OLEFINS Introduction The Wilkinson Catalyst Enantioselective Hydrogenation Dihydrogen Complexes and H2 Activation Transfer Hydrogenation HYDROFORMYLATION OF OLEFINS AND FISCHER-TROPSCH SYNTHESIS Cobalt Catalysts Phosphane-Modified Rhodium Catalysts Enantioselective Hydroformylation Significance of Hydroformylation and Outlook The Fischer-Tropsch Synthesis CARBONYLATION OF METHANOL AND WATER-GAS SHIFT REACTION Principles The Monsanto Process Synthesis of Acetic Anhydride The Cativa Process Water-Gas Shift Reaction and Carbon Monoxide Dehydrogenases METATHESIS Metathesis of Olefins Metathesis of Alkynes Enyne Metathesis Delta-Bond Metathesis Metathesis of Alanes OLIGOMERIZATION OF OLEFINS Ziegler Growth Reaction Nickel Effect and Nickel-Catalyzed Dimerization of Ethene Trimerization of Ethene Shell Higher Olefin and Alpha-Sablin Processes POLYMERIZATION OF OLEFINS Introduction Ethene Polymerization Propene Polymerization Metallocene Catalysts Nonmetallocene Catalysts Copolymerization of Olefins and CO C-C LINKAGE OF DIENES Introduction Allyl and Butadiene Complexes Organometallic Elementary Steps of Allyl Ligands Oligomerization and Telomerization of Butadiene Polymerization of Butadiene C-C COUPLING REACTIONS Palladium-Catalyzed Cross-Coupling Reactions The Heck Reaction Palladium-Catalyzed Allylic Alkylation HYDROCYANATION, HYDROSILYLATION, AND HYDROAMINATION OF OLEFINS Introduction Hydrocyanation Hydrosilylation Hydroamination OXIDATION OF OLEFINS AND ALKANES The Wacker Process Epoxidation of Olefins C-H Functionalization of Alkanes NITROGEN FIXATION Fundamentals Heterogeneously Catalyzed Nitrogen Fixation Enzyme-Catalyzed Nitrogen Fixation Homogeneously Catalyzed Nitrogen Fixation

Abstract: A novel transformation in which mono- or dialkyl-substituted furans are converted into 1,2-dihydropyridines upon reaction with PhI═NTs at room temperature is reported. The reaction is catalyzed by complexes of general formula TpxM (M = Cu, Ag) and consists of a one-pot procedure with four consecutive catalytic cycles. Furan aziridination is followed by aziridine ring-opening, transimination reaction, inverse-electronic-demand aza-Diels−Alder reaction, and a final hydrogen elimination reaction. The mechanism of the overall transformation is proposed where the metal complex displays a crucial role along the reaction pathway.

Abstract: A gold-catalyzed tandem cycloisomerization/functionalization of in situ generated α-oxo gold carbenes in water has been developed, which provides ready access to highly functionalized indole derivatives from o-alkynyl anilines and ynamides. Importantly, gold serves dual catalytic roles to mediate both the cycloisomerization of o-alkynyl anilines and the intermolecular oxidation of ynamides at the same time, thus providing a new type of concurrent tandem catalysis. The use of readily available starting materials, a simple procedure, and mild reaction conditions are other notable features of this method.