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.

3-Thienylacetic acid was converted in six steps into a new spirobi[thieno[2,3-c]pyran] (overall yield: 52%). The spirobi[thieno[2,3c]pyran] was selectively mono-or dimetalated with butyllithium and then transmetalated with zinc chloride; cross-coupling reaction with various aryl or heteroaryl bromides, including bromo-oligothiophenes, acid chlorides, and 1-bromopyrene, produced the corresponding spiro derivatives in high yields.

The novel spiro compound (VI) is synthesized in eight steps starting from commercially available 3-thienylacetic acid. The selective mono-or di-metalation of (VI) with butyllithium followed by transmetalation with ZnCl 2 and trapping with one or two electrophiles is demonstrated. Furthermore, the palladium-catalyzed cross-coupling of organozinc reagents with oligothiophene units or prenyl units leads to soluble building blocks such as compounds (XIV) and (XV). -(DHAYALAN, V.; ALCANIZ, F. R.; WERNER, V.; KARAGHIOSOFF, K.; KNOCHEL*, P.; Synthesis 47 (2015) 24, 3972-3982, http://dx.