Synthesis and characterization of homoleptic titanium bulky alkoxo complexes and their application in 1-octene epoxidation

• A family of new homoleptic titanium alkoxides has been prepared.
• The existence of monomer–dimer equilibrium is proposed.
• The structure of the complexes depends on the crowding effect of the alkoxo ligands.
• Titanium compounds have been studied in the epoxidation reaction of 1-octene with EHBP.

A new series of titanium alkoxo complexes [Ti(OR)4] (1–8) have been synthesized by the alcoholysis reaction of Ti(OiPr)4 with the corresponding alcohol (ROH = Adamantanol, (1R,2S,5R)-(−)-menthol, 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose, 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose, (1R)-(−)-myrtenol, 1,2:5,6-Di-O-cyclohexylidene-α-D-glucofuranose, (1S-endo)-(−)-borneol and (−)-sclareol). These homoleptic alkoxo titanium (IV) complexes have been characterized by spectroscopic and electrochemical techniques. In addition, they have been tested in the epoxidation reaction of 1-octene with ethylbenzene hydroperoxide as oxidant; obtaining yields of up to 90% and selectivity values of 50%. The conversion profile of EBHP was found to depend on the amount of titanium and on the chemical environment of titanium sites.

A new series of homoleptic titanium alkoxo complexes have been synthesized and characterized by spectroscopic and electrochemical techniques. They have been tested in the epoxidation reaction of 1-octene with ethylbenzene hydroperoxide. The conversion profile of EBHP was found to depend on the amount of titanium and on the chemical environment of titanium sites.Figure optionsDownload as PowerPoint slide