Palladium-catalyzed benzylation of active methine compounds without additional base: remarkable effect of 1,5-cyclooctadiene.

[reaction: see text] The palladium complex prepared from DPPF and Cp(eta3-C3H5)Pd is an effective catalyst for the alkylation of active methine compounds with benzylic carbonates under neutral conditions. The addition of 1,5-cyclooctadiene brought about remarkable improvement in the lifetime of the palladium catalyst, which led to high yields of the desired benzylation products.