A General Preparation of Polyfunctional Benzylic Zinc Organometallic Compounds

A new method for the preparation of highly functionalized benzylic zinc chlorides by the direct insertion of zinc dust into the corresponding benzylic chlorides in the presence of LiCl is described without the formation of homocoupling products (<5 %). Various reactions of these benzylic zinc reagents with a broad range of electrophiles, which lead to polyfunctionalized products, are reported. In particular, the cross-coupling reactions of the benzylic zinc chlorides with aromatic chlorides, bromides, and tosylates in the presence of [Ni(acac)(2)] (acac=acetylacetonate) and PPh(3) proceeded in good to excellent yields to give the corresponding diaryl and heterodiaryl methanes.