The lithiation of 2‐(aminomethyl)pyridine and the subsequent reaction with ClSiMe2tBu yields (tert‐butyldimethylsilyl)(2‐pyridylmethyl)amine (1). The metalation of 1 with dimethylzinc gives colorless dimeric methylzinc 2‐pyridylmethyl(tert‐butyldimethylsilyl)amide (2), which crystallizes in the triclinic space group P1¯. The solvent‐free thermal decomposition of 2 at 150 °C 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‐butyldimethylsilyl)(2‐pyridylmethyl)amido]zinc (4). Compound 3 can be obtained in good yield by reacting 2 with dimethylzinc 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 I41cd. The lithiation of 1 and the subsequent metathesis reaction with anhydrous ZnCl2 yields complex 4 almost quantitatively.

[reaction: see text] The presence of an electron-withdrawing group or chelating group was found to direct the halogen-copper and halogen-magnesium exchange with various di- or trihalogenated aromatics. Starting with a triiodobenzoate derivative, a range of tetraacylated benzenes could be prepared and used for a short synthesis of benzodiazines.

No abstract

No abstract

The lithiation of bis(triisopropylsilyl)phosphane with n-butyllithium in THF gave quantitatively dimeric (thf)LiP(SiiPr3)2 (1) with three-coordinate lithium atoms. The molecular structure of 1 shows Li-P bond lengths of 253.3(6) pm. In order to obtain the pentacarbonyltungsten complex of the sterically demanding phosphanide, (thf)W(CO)5 was reacted with (thf)LiP(SiiPr3)2 in THF. The resulting solvent-separated complex [(thf)4Li]+ [(OC)5WP(SiiPr3)2]− (2) was structurally characterized and shows a very large W-P distance of 266.65(7) pm.