Organotitanium compounds with alcohols

Among widely used organotitanium compounds are tetraalkoxytitaniums, obtained by the etherification of titanium tetrachloride with alcohols ... 

The above transformation has two different goals 21,22) 1) To increase chemo-, regio-, diastereo- and enantioselectivity in the reaction with carbonyl compounds (Sections C-E), and 2) to make certain reaction types amenable which do proceed readily with classical reagents, e.g., methylation of tertiary alkyl halides, alcohols and ethers, and direct geminal dialkylation of ketones (Section F). It turns out that organotitanium compounds are usually complementary to Li, Mg, Zn, Fe, Ni, Cu and Pd reagents. So far, experience in the above two areas points to the following positive aspects ... 

Organotitanium compounds having an optical active functional group react with an aldehyde to produce an optically active alcohol in high enantioselectivities of up to 88% ee as shown in eq. (12.32) [84]. 

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