Overview of the Negishi Protocol with Zn, Al, Zr, and Related Metals

1 Overview of the Negishi Protocol with Zn, Al, Zr, and Related Metals 

Metals of intermediate electronegativities exhibited, in general, the highest catalytic activities in Pd-catalyzed cross-coupling, as observed first in alkynyl-aryl coupling reaction (Table 1 in Sect. IILl). 

In cases where the Pd- or Ni-catalyzed cross-coupling reactions of alkenylalu-minum and alkenylzirconium derivatives are sluggish, addition of Zn salts (e.g., ZnCl2 and ZnBr2) has significantly accelerated these reactions in many cases (double metal 

Handbook of Organopalladium Chemistry for Organic Synthesis, Edited by Ei-ichi Negishi ISBN 0-471-31506-0 2002 John Wiley Sons, Inc. 

Organometals containing more electropositive metals (e.g Li and Mg) are generally most reactive in many different kinds of reactions. And yet, the catalytic reactivity of these metals, especially Li, in the Pd-catalyzed reaction is lower than that of Zn in many cases. Because of their high intrinsic reactivity toward many functional groups, they are not very chemoselective in a traditional sense. As a consequence of these two generally 

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E. Negishi, Overview of the Negishi Protocol with Zn, Al, Zr, and Related Metals, in Handbook of Organopalladiiun Chemistry for Organic Synthesis , ed. E. Negishi, John Wiley and Sons, Hoboken, NJ, 2002, p. 229. Editor. 

Negishi E-i (2002) Overview of the Negishi protocol with Zn, Al, Zr, and related metals. In Negishi E-i, de Meijere A (eds) Handbook of organopalladium chemistry for organic synthesis. Wiley, New York... 

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