Conjugate addition reactions alkenylmetals

Subsequent studies have estabhshed that conjugate substitution of /3-halo-a,/3-unsa-turated carbonyl compounds with alkenylmetals is a generally favorable reaction, which can be achieved by using B, Sn, and Zn in addition to A1 and Zr mentioned above. Although /3-iodo derivatives appear to be the most reactive, /3-bromo, /3-sulfonyloxy (e.g., TfO, MsO, FSO3), and even j8-chloro derivatives in some cases are satisfactory. Some representative examples of conjugate substitution with alkenylmetals are presented in Table 1. 

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