Octahedral Titanium(IV)-Reagents in Organic Synthesis

As part of our studies directed toward the use of organotitanium chemistry in organic synthesis1,2 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.