Regioselective Addition Reactions of 3-Phenylsulfonyl-2-trifluoromethyl--1,3-butadiene with Nucleophiles. -The regioselective addition of various nucleophiles to title compound (I) is studied. A stereoselective formation of pyrrolidine derivative (IV) is observed when amine addition product (IIId) is heated in 2,2,2-trifluoroethanol. That surprising cyclization seems to be pretty sensitive to the reaction conditions. -(YANG, E. J.; JEON, S. L.; JEONG*, I. H.; J. Fluorine Chem. 143 (2012) 198-203, http://dx.