OXAZOLINE EARLY TRANSITION-METAL COMPLEXES - FUNCTIONALIZABLE ACHIRALTITANIUM(IV), TITANIUM(III), ZIRCONIUM(IV), VANADIUM(III), AND CHIRALZIRCONIUM(IV) BIS(OXAZOLINE) COMPLEXES

Large-scale syntheses of the (hydroxyphenyl)oxazoline ligands L(1) = 6 , L(2) = 7, L(3) = 8, L(4) = 9, and L(5) = 10 are reported. The conver sion of 6-10 into the corresponding sodium salts has been employed for metal complexation. The reaction of 6 with TiCl4 . 2THF, TiCl3 . 3THF , ZrCl4 . 2THF, and VCl3 . 3THF in a 1:2 metal:ligand ratio afforded t he corresponding hexacoordinate functionalizable metal complexes: cis- [(Cl)(2)Ti(L(1))(2)], 11; cis-[(THF)(Cl)Ti-(L(1))(2)], cis-[(Cl)(2)Zr( L(1))(2)], 13; trans-[(THF)(Cl)V(L(1))(2)], 14. The structures of 11, 12, and 14 have been clarified by X-ray analysis. The reaction of the 8 and 9 sodium salts with ZrCl4 . 2THF in a 1:2 metal:ligand ratio led to the corresponding chiral functionalizable metal complexes, whose s tructures were clarified by X-ray analysis: cis-[(Cl)(2)Zr(L(3))(2)], 15; cis-[(Cl)(2)Zr(L(4))(2)], 16. A common significant feature discove red from these studies is the existence of intramolecular hydrogen bon ding, which is probably responsible for the high conformational rigidi ty of the oxazoline ligand. Crystallographic details are as follows: 1 1 is monoclinic, space group I2/a, with a = 16.443(2) Angstrom, b = 8. 365(1) Angstrom, c = 17.945(2) Angstrom, beta = 106.93(1)degrees, Z = 4, and R = 0.034; 12 is orthorhombic, space group Pca2(1) with a = 15. 669(2) Angstrom, b = 17.750(3) Angstrom, c = 18.971(3) Angstrom, Z = 8 , and R = 0.050; 14 is monoclinic, space group P2(1)/n, with a = 9.391 (4) Angstrom, b = 28.618(6) Angstrom, c = 12.077(4) Angstrom, beta = 1 05.79(2)degrees, Z = 4, and R = 0.052; 16 is monoclinic, space group P 2(1), with a = 10.161(2) Angstrom, b = 14.151(3) Angstrom, c = 12.361( 2) Angstrom, beta = 93.76(2)degrees, Z = 2, and R = 0.033.