Pyridines metal-mediated transformations

Metal-mediated transformations ofpyridines are thus mainly the realm of main group highly electron-rich compounds such as alkyl derivatives of Uthium, magnesium and zinc, aluminum hydrides, etc. This chemistry will be very succincdy covered with an emphasis on recent developments, as it will the related alkyl migration to pyridines which have been found in a number of f-block derivatives, a topic which has been recently reviewed. In particular, rollover cyclometalations, which are important processes that can be operative in bipy complexes, will not be mentioned, and the interested reader is referred to a recent account of this chemistry. 

Transition-metal-mediated C—X bond formation by intramolecular reactions with alkynes is a powerful strategy for the construction of heteroarene rings such as pyridines, pyrroles, and furans. Because of the wide availability of Sonogashira coupling of various haloarenes with terminal alkynes, these transformations provide efficient routes to synthesize fused heteroarenes, including isoquinolines, indoles, and benzofurans. In this chapter the construction of aromatic rings by transition-metal-catalyzed or transition-metal-mediated intramolecular C—X bond formation between C—X or X—H and alkynes is described. As shown in Scheme 19.1, Section... 

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