Phenyl transfer reactions diphenylzinc

In 2005, Pizzuti and Superchi [72b] applied catalysts with a l,l -binaphthylazepine skeleton (Figure 7.9, D), but only a maximum of 54% ee was obtained in the phenyl transfer reaction from diphenylzinc to 4-chorobenzaldehyde. 

It is important to mention that the catalysis with this modified arylzinc reagent not only leads to improved enantioselectivity (at high product yield), but also that in this process swfestoichiometric quantities of diphenylzinc could be applied. This also meant that now both of the phenyl groups could be activated and transferred to the aldehydes. A reaction profile obtained by FT-IR studies revealed that the modification of the zinc reagent had a significant effect on its reactivity [41]. 

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