Titanium complexes based on chiral enantiopure dialkanolamines: synthesis, structures and catalytic activity

New chiral enantiopure tridentate ligands (dialkanolamines) RN((CHRCRROH)-C-3-R-1-O-2)((CHRCRROH)-C-4-R-5-O-6) 10-17 were synthesized by the opening of the epoxide ring by the action of the amines or alkanolamines. Titanium complexes, viz. [RN((CHRCRRO)-C-3-R-1-O-2)((CHRCRRO)-C-4-R-5-O-6)]Ti(O-i-Pr)(2) 18-23 and [RN((CHRCRRO)-C-3-R-1-O-2)((CHRCRRO)-C-4-R-1-O-6)](2)Ti 25-31 were synthesized by treatment of Ti(O-i-Pr)(4) With one or two equivalents of corresponding dialkanolamines. Complex (R)-PhCH(Me)N(CH2C(Me)(2)O)(2)TiCl2*HNMe2 24 was obtained from the reaction of One equivalent of dialkanolamine 10 with (Me2N)(2)TiCl2. The composition and Structure of all novel compounds were established by H-1 and C-13 NMR spectroscopy as well as elemental analysis. The possible Solution structures of 18-31 are discussed. The single-crystal X-ray diffraction study of 23, 25-28, 30 31 indicates monomeric Structures ill the solid state. Chiral complexes 20, 22, 23 25, 26, 30 were tested as chiral catalysts in the Abramov reaction and demonstrated moderate enantiomeric activity.