Synthetic organometallic chemistry

The attack on coordinated carbon monoxide by nucleophiles was first extensively developed in synthetic organometallic chemistry by E. 0. Fischer and his students (6) as discussed by others in this volume, this reaction provides one route to the reduction of coordinated CO and to catalysis of the water gas shift reaction. Those carbonyl groups which are susceptible to attack by nucleophiles are electron deficient, as judged by their high CO stretcing frequencies (7). 

Characterizations of the metallacarbaborane species described in this review and in our earlier article (1) would not have been possible without modem tools of analysis. Of crucial importance to this work are high-field multinuclear magnetic resonance spectroscopy and single-crystal X-ray diffraction analysis, two cornerstones of synthetic organometallic chemistry. It is therefore appropriate to highlight certain diagnostic features that are essential to the successful application of these techniques. 

Vacuum sublimation is a convenient purification technique, frequently used in synthetic organometallic chemistry. There are many types of sublimation flasks, varying chiefly in degree of sophistication of design. The main practical problem with vacuum sublimation is the inefficient transfer of heat from heat source to the sample being sublimed. Virtually all set ups use an oil- or metal bath and rely on conduction as the main mechanism of heat transfer. Under the vacuum conditions of the usual sublimation (10 - 10 mm Hg) both... 

Multipurpose Vacuum Line Designs for Use in Synthetic Organometallic Chemistry... 

If we have been successful in our aims, the reader should be able to scan the following chapters and choose the methods or characterization techniques that best suit the chemistry at hand. She or he should at the same time acquire an appreciation for less familiar methodology (or at least be made aware of their existence and potential use in the future). Finally, we hope that these accounts, written from the viewpoint of organometallic chemists, spectroscopists, and theoreticians who are enthusiastic innovators in the topics described, will provide the interested reader with the sense of art that is implicit in synthetic organometallic chemistry but that of necessity is sadly lacking in the concise detail of the experimental sections of our papers (8,9). 

Radical reactions in synthetic organometallic chemistry are rare but gain increasing importance. A recent example demonstrated that molybdenum difluoroboroxycarbenes may serve as radical precursors and allow to generate acyl radicals under mild reaction conditions. [91] Coupling of molybdenum difluoro-boroxycarbene 84 to vinylketone 85 and aldehyde 86 leads diastereoselectively to vr -P-hydroxyketone 87 (Scheme 38). Using the chiral aldehyde 88 a diastereofacial selectivity of more than 99% d.e. was observed for the formation of 89 (Scheme 39). 

This paper has discussed the electrochemistry of metal-carbon and metal-metal bonded metalloporphyrins. The field is quite new and the majority of published studies result from work carried out in our own laboratory during the period 1984 to 1987. To date, relatively few examples of a-bonded metal-carbon and metal-metal bonded metalloporphyrins are known, but it is theoretically possible to prepare and characterize representative complexes with almost all elements in the periodic table. The field is rapidly expanding and future synthetic developments in porphyrin chemistry should certainly lead to new complexes possessing different metal-metal or metal-carbon interactions and possibly different electrochemistry. These types of complexes are of interest in modelling some biological processes, in synthetic organometallic chemistry and in the preparation of new poljrmeric materials with conducting properties. 

Organometallic compounds of copper were known for a long time before their versatil ity in synthetic organic chemistry was fully appreciated The most useful ones are the lithium dialkylcuprates which result when a copper(I) halide reacts with two equivalents of an alkyllithium in diethyl ether or tetrahydrofuran... 

You have already had considerable experience with carbanionic compounds and their applications in synthetic organic chemistry The first was acetyhde ion m Chapter 9 followed m Chapter 14 by organometallic compounds—Grignard reagents for example—that act as sources of negatively polarized carbon In Chapter 18 you learned that enolate ions—reactive intermediates generated from aldehydes and ketones—are nucleophilic and that this property can be used to advantage as a method for carbon-carbon bond formation... 

Throughout each chapter, clear structures, schemes, and figures accompany the text. Mechanism, reactivity, selectivity, and stereochemistry are especially addressed. Special emphasis is also placed on introducing both the logic of total synthesis and the rationale for the invention and use of important synthetic methods. In particular, we amplify the most important developments in asymmetric synthesis, catalysis, cyclization reactions, and organometallic chemistry. 

P decay offers to pure chemistry a means of answering the question of the existence of unknown molecules. Failure to observe a particular compound in the systematics of organometallic chemistry can have several reasons. Most commonly it is because the preparative methods used are inappropriate. This is poor evidence for the non-existence of a compound, and shows as a rule only that the derived structure cannot be reached by the synthetic route chosen, p decay, on the other hand, starts... 

Last year saw the publication of an extremely useful book on synthetic techniques applicable to both inorganic and organometallic chemistry. 

The following is a comprehensive smwey of the chemistry of macrocycles comprised entirely of phenyl and acetylenic moieties. Although over fom" decades old, this area of research has come into its own just in the last few years. Widespread interest in the field has been spurred by recent discoveries utilizing these compoimds as ligands for organometallic chemistry, hosts for binding guest molecules, models of synthetic carbon allotropes, and precursors to fullerenes and other carbon-rich materials. This review will discuss the preparation of a tremendous variety of novel structm-es and detail the development of versatile synthetic methods for macro cycle construction. 

Part II Macromolecules Catalysis Colloid Science Electrochemistry Electron Spin Resonance Environmental Chemistry Genetal and Synthetic Methods Mass Spectrometry Nuclear Magnetic Reson n e Organometallic Chemistry Organophosphorus Chemistry Photochemistry... 

Frankland discovered the fundamental principle of valency—the combining power of atoms to form compounds. He gave the chemical bond its name and popularized the notation we use today for writing chemical formulas. He codiscovered helium, helped found synthetic organic and structural chemistry, and was the father of organometallic chemistry. He was also the first person to thoroughly analyze the gases from different types of coal and—dieters take note—the first to measure the calories in food. 

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