Low valent tungsten reaction—Composition studies and reactions with sulfoxides and pyridine-N-oxides

Sulfoxides are converted to the corresponding sulfides in good yields by low valent tungsten agents derived from WCl₆—BuLi(1) and WCl₆—Zn (2). Pyridine-N-Oxides are also reduced easily with 1 to give the corresponding pyridines in almost quantitative yields. A yellow solid WCl₄ (THF)_n is isolated from the reaction of one mole of WCl₆ and two mole of n-BuLi in tetrahydrofuran (THF) at low temperature, and its composition is established by using ESCA. IR, ¹H and ¹²C NMR. Reaction of WCl₄ (THF)_n with excess of pyridine gives the known WCl₄(C₅H₅N)₂.