Direct functionalization of the benzylic C–H bond of diarylmethanes is an important strategy for the synthesis of diarylmethine-containing compounds. However, the methods developed to date for this purpose require a stoichiometric amount (usually more) of a strong base or an oxidant. Herein, we report the first catalytic benzylic C–H bond addition of diarylmethanes to styrenes and conjugated dienes. A potassium zincate complex generated from potassium benzyl and zinc amide acted as the catalyst and displayed good activity and chemoselectivity. Considering the atom economy of the reaction and the ready availability of the catalyst, this reaction constitutes a practical, efficient method for diarylalkane synthesis.
Read more: http://onlinelibrary.wiley.com/doi/10.1002/anie.201713165/epdf.