Halogenated organometallic compounds

Similarly, several other covalent molecules, such as halogens, organometallic compounds, and carbon tetrachloride, take part in such reactions. Susuki and Tsuji reported that addition of carbon tetrachloride to olefins and carbonyla-tion are catalyzed by dinuclear metal carbonyl complexes like [7r-CsHsFe(CO)2]2 and [7r-CsH5Mo(CO)3 ]2 S8-S9>. 

VALUES OF RATE COEFFICIENTS FOR REACTIONS OF HALOGENATED ORGANOMETALLIC COMPOUNDS WITH SODIUM VAPOUR... 

A. G. MacDiarmid, Organometallic Compounds of the Group IV Elements, Vol. 2, The Bond to Halogens and Halogenoids, Marcel Dekker, Inc., New York, 1972. 

It seems likely that the mechanism of the Wurtz reaction consists of two basic steps. The first is halogen-metal exchange to give an organometallic compound (RX -(- M —+ RM), which in many cases can be isolated (12-36). Following this, the organometallic compound reacts with a second molecule of alkyl halide (RX + RM —> RR). This reaction and its mechanism are considered in the next section (10-94). 

Replacement of a Halogen by a Metal from an Organometallic Compound... 

Reaction of aryl organometallic compounds with halogens Aryl halide exchange halo-denitration halo-dehydroxylation Reaction between diazonium salts and iodide ion Heating of diazonium fluoroborates (Schiemann)... 

Halogenation of alkenyl organometallic compounds Addition of hydrogen halides to triple bonds Halogenation of alkynes or allenes Addition of alkyl halides to triple bonds Addition of acyl halides to triple bonds... 

Organometallic compounds or carbanions undergo a number of reactions in which the carbanion or carbanion-like moiety of the organometallic compound acts as a nucleophilic displacing agent. Examples are the formation of hydrocarbons from alkyl halides, alkyl halides from halogens, and ketones from acid chlorides or esters. The latter two reactions are closely related to the base-catalyzed condensations and are perhaps additions as well as displacement reactions. Related addition reactions are the carbonation of organometallic compounds and the addition to ketones or aldehydes. 

The polarity of carbon-halogen bond of alkyl halides is responsible for their nucleophilic substitution, elimination and their reaction with metal atoms to form organometallic compounds. Nucleophilic substitution reactions are categorised into and on the basis of their kinetic properties. Chirality has a profound role in understanding the reaction mechanisms of Sj l and Sj 2 reactions. Sj 2 reactions of chiral all l halides are characterised by the inversion of configuration while Sj l reactions are characterised by racemisation. 

Some unexpected reactions are observed during the interaction of cyclo-hepta[c]thien-6-one (231) or its 1,3-dibromo derivative and organometallic compounds (74YZ1429) These reactions are halogen-metal interconversion and subsequent dimerization, partial debromination, and simultaneous 1,2- and 1,4-addition of phenyllithium onto tropone 231 to yield tropylium salts 232 and 233, respectively (Scheme 56). 

Since dioxiranes are electrophilic oxidants, heteroatom functionalities with lone pair electrons are among the most reactive substrates towards oxidation. Among such nucleophilic heteroatom-type substrates, those that contain a nitrogen, sulfur or phosphorus atom, or a C=X functionality (where X is N or S), have been most extensively employed, mainly in view of the usefulness of the resulting oxidation products. Some less studied heteroatoms include oxygen, selenium, halogen and the metal centers in organometallic compounds. These transformations are summarized in Scheme 10. We shall present the substrate classes separately, since the heteroatom oxidation is quite substrate-dependent. 

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