Redistribution reactions organic compounds

The mixed methyl-ethyl tetraalkyllead compounds have become quite important commercially in the past several years because of their excellent antiknock effects and volatilities (see Extent of Antiknock Effect). Sometimes tetramethyllead and tetraethyllead are simply mixed together in motor fuel, but usually the compounds are subjected to "redistribution of the methyl and ethyl groups. The redistribution reaction involves the exchange of the organic groups between the compounds, yielding practically a random equilibrium production of all the possible products in a statistical distribution, as shown in the equation ... 

Olefin metathesis has emerged as a powerful tool for the preparation of cyclic organic compounds. Metathesis involves the redistribution of carbon-carbon double bonds in the presence of metal carbene complexes ([M]=CR2). The reaction of these metal carbenes with a,co-dienes leads to well-defined carbocyclic systems in what is termed ring-closing olefin metathesis (RCM). ... 

The RAlXj, R2AIX or sesquihalides (RXAIX2AIR2) are available by the reaction of metallic Al with organic halides (RX) (see 5.3.3.2.2.) Redistributions of these compounds, similar to Eqs. (a) and (b), take place smoothly between the sesquihalides and AIX3 to give RAIX2 ... 

The probability of reactions between oxidants and organic compounds is typically higher at material surfaces than in the air, since adsorbed compounds are more likely to be oxidized when the inteimolecular forces responsible for the adsorption also cause redistribution of electrons. Oxidants may react with non- or semi-volatile organic compounds on the surfaces. The reaction products will typically be more volatile (Reiss et al.,... 

The borders between the three stages are, of course, not sharp and even today the improvement of methods of preparation for simple lead alkyls such as tetraethyllead or tetrabutyllead is of great importance. But the following remarks are meant to deal mainly with the third and newest part of the development. This decision is an easy one because the developments until 1936 149), until 1952 161), and to the middle of 1963 273, 274) are treated in excellent reviews. Also there are critical reports on some topics, for instance, Catenated Organic Compounds of. .. Pb (77), redistribution reactions 185, 190), molecular complexes (76), and sulfur-containing alkyllead compounds ). The literature up to 1964 has been compiled by Dub (52). For 1964, 1965, and 1966 annual surveys 250) are available. 

Fluoride anion strongly interacts with various inorganic and organic boron and silicon compounds. These reactions are the basis for several fluoride sensors. Interaction of fluoride with boron compounds results in electron density redistribution and may also induce structural changes. Formation of fluoride complex by ferrocene derivative (Figure 16.19a) results in a decrease of oxidation potential by 200 mV... 

---