Understanding the Regiodivergence between Hydroarylation and Trifluoromethylarylation of 1,3-Dienes Using Anilines in HFIP

Conjugated dienes (1,3-dienes) are versatile and valuable
chemical
feedstocks that can be used as two-carbon or four-carbon synthons
with vast applications across the chemical industry. However, the
main challenge for their productive incorporation in synthetic routes
is their chemo-, regio-, and stereoselective functionalization. Herein,
we introduce a unified strategy for the 1,2-hydroarylation and 1,4-trifluoromethylarylation
of 1,3-dienes using anilines in hexafluoroisopropanol. DFT calculations
point toward a kinetically controlled process in both transformations,
particularly in the trifluoromethylarylation, to explain the regiodivergent
outcome. In addition, we perform an extensive program of functionalization
and diversification of the products obtained, including hydrogenation,
oxidation, cyclizations, or cross-coupling reactions, that allows
access to a library of high-value species in a straightforward manner.