91389-10-5Relevant academic research and scientific papers
Enantioselective Grignard-type addition of allyltitanium reagents having the center of chirality at titanium
Reetz, Manfred T.,Kyung, Suk-Hun,Westermann, Jürgen
, p. 1716 - 1717 (2008/10/08)
Addition of allylmagnesium chloride to the chiral and racemic titanium(IV) compound CpCp′Ti(C6F5)Cl, in which Cp = η5-C5H5 and Cp′ = η5-C5H4C(CH3)3, yields CpCp′Ti(C6F5)C3H5. The latter reacts diastereoselectively with aldehydes to afford adducts of the type CpCp′Ti(C6F5)OCHRC3H5, diastereomeric excess (de) being 12-40%. Optically active (+)-CpCp′Ti(C6F5)Cl was also treated with allylmagnesium chloride, benzaldehyde added, and the adduct hydrolyzed in a one-pot reaction to provide the Grignard-type adduct. Enantiomeric excess (ee) amounts to 11%. Since the de value in the racemic series is 20%, loss of chiral information is occurring, possibly during the addition of allylmagnesium chloride to (+)-CpCp′Ti(C6F5)Cl.
