The metalation of (tert-butyldimethylsilyl)(2-pyridylmethyl)amine with dimethylzinc and subsequent zinc-mediated carbon-carbon coupling reaction

The lithiation of 2-(aminomethyl)pyridine and the subsequent reaction with ClSiMe(2)tBu yields (tert-butyldimethylsilyl) (2-pyridylmethyl)amine (1). T he metalation of 1 with dimethylzinc gives colorless dimeric methylzinc 2-p yridylmethyl(tert-butyldimethylsilyl)amide (2), which crystallizes in the t riclinic space group P (1) over bar. The solvent-free thermal decomposition of 2 at 150 degreesC leads to the evolution of methane, the precipitation of zinc metal and the formation of amine 1, bis(methylzinc)-1,2-dipyridyl-1 ,2-bis(tert-butyldimethylsilylamido)ethane (3), and bis[(tert-butyldimethyl silyl) (2-pyridylmethyl)amido]zinc (4). Compound 3 can be obtained in good yield by reacting 2 with dimethylzine at elevated temperatures in toluene. During this reaction, zinc metal precipitates and methane is evolved. The C -C coupling product 3 crystallizes in the tetragonal space group I4(1)cd. T he lithiation of 1 and the subsequent metathesis reaction with anhydrous Zn Cl2 yields complex 4 almost quantitatively.