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Halogen Dance (HD) reactions are a useful tool for synthetic chemists as they enable access to positions in aromatic and heteroaromatic systems for subsequent functionalization which are often difficult to address by other methods, hence, allowing entry to versatile scaffolds. While the method can be extremely useful, this transformation is often neglected upon designing synthetic sequences. This may be largely attributed to the lack of comprehensive reference works covering the general principles and outlining the versatility and limitations of the technique. The following review tries to present HD reactions in a clear and concise manner in order to convince more chemists of its advantages. It covers the field of HD reactions from their first observation in 1951 until the present. The important contributions leading to the elucidation of the mechanism are briefly outlined followed by a detailed mechanistic section and a discussion of factors which influence HD reactions. Finally, an overview of HD reactions on various carbocyclic and heterocyclic ring systems and its applications in the synthesis of complex compounds is given.

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Recent progress in the field of transition‐metal‐catalyzed cross‐coupling reactions on various azole systems is summarized. Most important C–C‐ and C–X‐bond formation methodologies (Negishi, Suzuki–Miyaura, Stille, Kumada–Corriu–Tamao, Hiyama, Sonogashira, Heck, C–H activation) are reviewed and discussed for the imidazole, oxazole, thiazole, pyrazole, isoxazole, and isothiazole system, as well as for azoles with more than two heteroatoms. This review covers the literature that appeared in the past ten years up to the end of 2005 with corresponding azoles used either as metal organyl or halide (including triflates and some other less frequently applied leaving groups); literature describing azole structures only as ligands was not included.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Evaluation of the results of a study, undertaken to examine the influence of the main reaction parameters (lithiation temperature, concentration, lithiating agent, and solvent) on the course of the title reaction, subsequently led to the development of an improved and more generally-applicable lithiation procedure. Hitherto unpublished stability data for solutions of t-BuLi and n-BuLi/TMEDA in diethyl ether and THF are reported for various temperatures.Scheme I