Bulky metal aryloxides, arylamides, and sulphur and phosphorus analogues. Part 1. Synthetic and chemical studies of titanium and zirconium aryloxides

The synthesis and characterisation of several classes of aryloxides (OR) of TiIV, TiIII, ZrIV, and Li are described. Those of TiIV are of eight distinct classes: [Ti(OR)4], [TiCl2(OR)2], [TiCl2(OR)2(thf)2], [Ti(NMe2)2(OR)2], [Ti(OMe)2(OR)2], [TiCl(OR′)(OR)2], [TiCl(R′)(OR)2], and [TiCl(η-C5H5)(OR)2](R′= alkyl, thf = tetrahydrofuran); the TiIII complexes are of types [{TiCl(OR)2}n] and [Ti(η-C5H5)2(OR)]; the ZrIII complexes are of seven types: [ZrCl2(OR)2] and [Zr(η-C5H5)2(OR)X], with X = OR, Cl, NMe2, OMe, OC(O)NMe2, or N(Ph)C(O)NMe2; the new lithium aryloxides have formula [Li(OR)(OEt2)]n. Most of the results relate to the ligands 2,6-Me2C6H3O–, 2,6-Pri2C6H3O–, 2,6 But2C6H3O–, 4-Me-2,6-But2C6H2O–, 2,4,6-But3C6H2O–, 3,5-But2C6H3O and 2,4-But2C6H3O–. The new complexes are readily soluble in diethyl ether and many also in hydrocarbons. Synthetic procedures include the following systems: (i) LiBun–ROH–OEt2, for Li aryloxides; (ii) TiIV, TiIII, or ZrIV chlorides with [Li(OR)(OEt2)]n; (iii) for TiIII, a redox reaction of type (ii) using a TiIV chloride as precursor; (iv) a TiIV or ZrIV dimethylamide and ROH; and (v) for the ZrIV carbamate or ZrIV urea, a CO2 or PhNCO insertion into the appropriate ZrIV dimethylamide.