Octahedral Titanium(IV)-Reagents in Organic Synthesis

Abstract

As part of our studies directed toward the use of organotitanium chemistry in organic synthesis^1,2 we wish to report that stable hexa-coordinate octahedral complexes³ of methyltitaniumtrichloride (1) are diastereoand enantioselective methylating reagents. The reaction of tetramethylethylene diamine³ (TMEDA), glyme³ tetrahydrofuran³ or (?)-sparteine with the equivalent amount of 1 in CH₂Cl₂ yields compounds 2, 3, 4 and 5 respectively. These were allowed to react in situ with 2-phenylpropionaldehyde at ?50 °C in CH₂Cl₂ for two hours.