S. Nowotny et al., DRAMATIC TITANIUM ALKOXIDE EFFECT IN THE CATALYTIC ENANTIOSELECTIVE ADDITION OF DIALKYLZINCS TO ALDEHYDES, Tetrahedron letters, 35(26), 1994, pp. 4539-4540
The use of Ti(Ot-Bu)(4) or related bulky titanium(IV) alkoxides, as co
catalysts instead of Ti(Oi-Pr)(4) in the enantioselective addition of
dimethylzinc to aldehydes in the presence of the catalyst 2 (8 mol%) l
eads to a dramatic improvement of the enantioselectivity (0%ee to 93%e
e). The scope and the limitations of this effect are described.