Titanium, chlorotris reaction with aldehydes

Perfluoroalkyl- and perfluoroaryltitanium compounds were prepared m situ via reaction of the corresponding Gngnard reagents with chlorotris(diethyl-amido)titanium [28S] Reaction of the titanium compounds with aldehydes resulted in fluoroalkylative amination [288] (equation 192)... 

The 2-butenyltitanium reagents are generated by the deprotonation of an E-2-butenylcarbamate 279 with n-butyllithium and then reaction of the newly formed allylic lithium species 280 with chlorotris(diethylamino)titanium [179]. The 2-bu-tenyltitanium reagent 281 is then combined with aldehydes to produce homoallylic alcohols 282 in high yield and excellent regioselectivity (Scheme 10-93). The enol carbamate moiety is readily converted to a carbonyl group and thus constitutes a homoaldol reaction. 

The addition of aziridinyl anions to aldehydes gave the alcohols 31 in good yields15. As with the oxiranyl anions, the diastereoselectivity of the addition reaction could be substantially enhanced by transmetalation of the lithium reagent with chlorotris(dimethylamino)titanium. 

---