organometallic compounds

Dedicated fondly to Professor J.F. Normant on the occasion of his 65th birthday The addition–b-elimination mechanism is a powerful method for the production of organometallic derivatives. Using this new method, we report the first transformation of enol ethers into the corresponding vinyl zirconium derivatives. Moreover, the in situ formation of Ti(II) and subsequent reaction with halogeno alkynes offers a new route for the preparation of functionalized alkynyl titanium and trismetalated olefin derivatives. © 2001 Elsevier Science B.V. All rights reserved. Numerous methods for the preparation of organometallic compounds are known in the literature and can be mainly divided into four categories [1]. The first, and probably the most important one, is the reaction between an organic halide or pseudo halide and a metal such as the classical oxidative metalation or the halogen–metal exchange [2]. The second cate-gory, also very popular and recently reviewed [3], con-cerns the exchange reactions between acidic hydrogen