Metal catalyzed organic reaction

G. Lindeberg, M. Larhed, A. Hall-berg (Labwell AB), Method for Organic Reactions -Transition Metal Catalyzed Organic Reactions. PCT International Application WO 43,230,1997 (SE Application 96/3,913, 25 Oct 1996) Chem. Abstr. 1998, 328,34382c. 

Ionic liquids serve as very useful reaction media, which can facilitate easy separation of product(s) and a catalyst after the reaction. These substitutes of organic solvents as reaction media have already been successfully applied to a variety of transition metal-catalyzed organic reactions such as Heck reaction, Suzuki cross-coupling, hydroformyla-tion, and alkoxycarbonylation. ... 

The carbonylation of C-X derivatives represents a large family of related homogeneous metal-catalyzed organic reactions (eq. (1)). Prominent members include hydroxy, alkoxy, and amido carbonylations, and double carbonylations. 

The enantiomers of VANOL (l,l -dihydroxy-3,3 -diphenyl-2,2 -binaphthyl) or its phenanthrene analogue VAPOL (l,l -dihydroxy-3,3 -diphenyl-2,2 -biphenanthryl) have been tested as BINOL substitutes in various nontransition metal catalyzed organic reactions (69,70). 

Tremendous recent advances in transition metal-catalyzed organic reactions may allow controlled functionalization of polyolefins under mild conditions. As illustrated in this review, some of these catalytic polymer modification processes have already demonstrated great potential for the synthesis of novel functional polymers from easily available low-cost starting materials. We expect the catalytic functionalization of unreactive C—H bonds of polyolefins (both saturated and unsaturated) to gain attention as a versatile synthetic approach to the creation of functional polymers in the future. 

This chapter is intended to cover the progress made in the study of the physicochemical properties of DESs and their applications as environmentally-friendly reaction media in a variety of chemical applications (i.e., electrochemistry, biocatalysis, metal extraction, material chemistry, and metal-catalyzed organic reaction). As this is a fast growing and widespread field, the author will try to give a general trend of this research area. 

Some of the critical enzymes in our cells are metalloproteins, large organic molecules made up of folded polymerized chains of amino acids that also include at least one metal atom. These metalloproteins are intensely studied by biochemists, because they control life and protect against disease. They have also been used to trace evolutionary paths. The d-block metals catalyze redox reactions, form components of membrane, muscle, skin, and bone, catalyze acid-base reactions, control the flow of energy and oxygen, and carry out nitrogen fixation. 

Dell C. P. Cycloaddition in Synthesis Contemporary Organic Synthesis 1997 4 87 Keywords natural products, metal catalyzed, asymmetric reactions, Ionic reactions, transannular reactions, tethered reactions, tandem reactions, benzo-qulnones, quinodimethanes, hefero-Dlels-Alder reactions... 

Precious metals have faced a significant price increase and the fear of depletion. By contrast, iron is a highly abundant metal in the crust of the earth (4.7 wt%) of low toxicity and price. Thus, it can be defined as an environmentally friendly material. Therefore, iron complexes have been studied intensively as an alternative for precious-metal catalysts within recent years (for reviews of iron-catalyzed organic reactions, see [12-20]). The chemistry of iron complexes continues to expand rapidly because these catalysts play indispensable roles in today s academic study as well as chemical industry. 

The Sonogashira reaction is a transition metal-catalyzed coupling reaction which is widely used for the preparation of alkyl-, aryl- and diaryl-substituted acetylenes (Table 4.7) [120]. This reaction is a key step in natural product synthesis and is also applied in optical and electronic applications. Sonogashira reactions involve the use of an organic solvent with a stoichiometric portion of a base for capturing the... 

Organic halides play a fundamental role in organic chemistry. These compounds are important precursors for carbocations, carbanions, radicals, and carbenes and thus serve as an important platform for organic functional group transformations. Many classical reactions involve the reactions of organic halides. Examples of these reactions include the nucleophilic substitution reactions, elimination reactions, Grignard-type reactions, various transition-metal catalyzed coupling reactions, carbene-related cyclopropanations reactions, and radical cyclization reactions. All these reactions can be carried out in aqueous media. 

There are many other transition-metal catalyzed coupling reactions that are based on organic halides in aqueous media. One example is the coupling of terminal alkyne with aryl halides, the Sonogashira coupling, which has been discussed in detail in the chapter on alkynes (Chapter 4). An example is the condensation of 2-propynyl or allyl halides with simple acetylenes in the presence of copper salts. 

Metal-catalyzed C-H bond formation through isomerization, especially asymmetric variant of that, is highly useful in organic synthesis. The most successful example is no doubt the enantioselective isomerization of allylamines catalyzed by Rh(i)/TolBINAP complex, which was applied to the industrial synthesis of (—)-menthol. A highly enantioselective isomerization of allylic alcohols was also developed using Rh(l)/phosphaferrocene complex. Despite these successful examples, an enantioselective isomerization of unfunctionalized alkenes and metal-catalyzed isomerization of acetylenic triple bonds has not been extensively studied. Future developments of new catalysts and ligands for these reactions will enhance the synthetic utility of the metal-catalyzed isomerization reaction. 

This chapter has been organized into three sections. The first section deals with transition metal-catalyzed hydroboration in organic synthesis and this is divided into three subsections - mechanism, chemoselectivity, and stereoselectivity. The second section deals with the application of transition metal-catalyzed hydroalumination reactions in organic synthesis, and this is also divided into three subsections - mechanism, chemoselectivity, and stereoselectivity. The third section examines the application of both hydroborations and hydroaluminations in total synthesis. 

Metal-catalyzed alcoholysis reactions of carboxylate and organophosphorus esters, 42, 271 Metal complexes, the nucleophilicity of towards organic molecules, 23, 1 Methyl transfer reactions, 16, 87... 

Since the epoxidation of alkenes with peracids was discovered by Prilezajew in 1909 [29], epoxides have played a major role in organic chemistry and industry, providing important intermediates for the synthesis of more complex molecules. Metal-catalyzed epoxidation reactions have received much attention in recent decades since the discovery of the Sharpless epoxidation [30, 31], but most epoxides were prepared from alkenes primarily by their interaction with peracids. 

Transition metal-catalyzed carbocycUzation reactions of tethered diene, enyne, diyne, and vinylallene derivatives represent an important class of transformations in synthetic organic chemistry. This may be attributed to the abihty to significantly increase molecular complexity through the highly selective combination of acyclic components, thereby facilitating the synthesis of complex polycychc products. Recently, rhodium-catalyzed carbocyclization reactions have attracted significant attention due to their immense synthetic versatility and the unique selectivities observed over a range of different transformations. This chapter provides an account of recent developments in rhodium-catalyzed [4-1-2] and [4-i-2-t2] carbocyclization reactions. 

Lutetium occurs in nature in small amounts in yttrium-containing minerals. It is found in xenotime, precambrian granites, and North American shales. It also exists at 0.001% in monazite, from which the metal is produced commercially. Lutetium has very httle commercial apphcation. The metal emits beta particles after thermal neutron activation, and is used to catalyze organic reactions. 

This review deals with the recent developments in the transition metal-catalyzed carbonylation reaction, especially hydroformylation, hydrocarbonylation, and oxidative hydrocarbonylation reactions of olefins, referring to literature since 1994. Because of the importance of carbonyl functionality in organic chemistry and the ideal atom efficiency of... 

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