A binaphtolate titanium complex featuring a linear tetradentate [OSSO]-bis(phenolato) ligand: Synthesis and partial hydrolysis to a homochiral dinuclear complex

Reaction of [{(R)-C20H12O2}Ti(OiPr)2] with 1,4-dithiaalkanediyl-2,2′-bis(6-tert-butyl-4-methyl-phenol) affords the chiral-at-metal complex [{(R)-C20H12O2}Ti{(C6H2O-tBu-6-Me-4)2S(CH2)2S}] (1) in low diastereomeric excess. Complex 1 can be partially hydrolyzed to give a dinuclear species [μ-{(R)-C20H12O2}-μ-O-{(Λ)-Ti[(C6H2O-tBu-6-Me-4)2S(CH2)2S]}2] (2), in which the two titanium centers are homochiral. The molecular structure of 1 and 2 was confirmed by single crystal X-ray analysis, which shows C2-symmetry in both complexes.

Graphical abstractThe chiral-at-metal complex [{(R)-C20H12O2}Ti{(C6H2O-tBu-6-Me-4)2S(CH2)2S}] is available from reaction of [{(R)-C20H12O2}Ti(OiPr)2] with 1,4-dithiaalkanediyl-2,2′-bis(6-tert-butyl-4-methyl-phenol) in low diastereomeric excess. Partial hydrolysis of this complex results in the formation of a dinuclear species [μ-{(R)-C20H12O2}-μ-O-{(Λ)- Ti[(C6H2O-tBu-6-Me-4)2S(CH2)2S]}2], in which the two titanium centres are homochiral.Figure optionsDownload full-size imageDownload as PowerPoint slide