Intramolecular Cycloaddition Azomethine Ylides and α-(Trifluoromethyl)styrenes as Dipolarophiles

The synthesis of polycyclic fluorinated tertiary amines has been accomplished by means of an intramolecular azomethine ylide cycloaddition with fluorinated dipolarophiles. Thus, tri- and tetracyclic fused pyrrolidines bearing a quaternary trifluoromethyl group were obtained in moderated yields in a stereoselective manner. This is one of the few examples reported in the literature of intramolecular 1,3-dipolar cycloaddition of azomethine ylides with fluorinated dipolarophiles. Initial attempts of the asymmetric version of the process have been performed, but low levels of diastereoselectivity were achieved.