Metallacycles, literature review

From the results discussed so far, it is evident that only CH2 groups have been observed in the very early stages of the ethylene polymerization reaction. Of course, this could be due to formation of metallacycles, but can be also a consequence of the high TOP which makes the observation of the first species troublesome. To better focalize the problem it is useful to present a concise review of the models proposed in the literature for ethylene coordination, initiation, and propagation reactions. 

Comprehensive coverage has not been attempted, but rather the intention has been to provide an introduction for the non-specialist which illustrates the scope of the field and highlights the main features of interest to organic chemists. Citation of all relevant publications is impracticable because of the large volume of literature. However, it is hoped that those key papers and specialist review articles which are included will enable the reader to locate related literature of interest. Advances in the chemistry of metallacycles and metal-hydrocarbon ir-complexes are thoroughly reviewed in surveys of organometallic chemistry published annually since 1972 (B-72MI12200). 

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