Diastereoselective Ti-mediated preparation of bicyclic aminocyclopropanes from N-alkenyl amides

Intramolecular Ti-mediated alkene–amide couplings of a range of N-alk-3-enyl amides fitted with a substituent at the homoallylic position are described. CF3-substituted compounds are suitable substrates and bicyclic aminocyclopropanes bearing a CF3 group can be prepared in this way. Good diastereoselectivities can be observed depending on the substitution pattern, and best results are obtained in diethyl ether rather than in THF.