1105579-08-5Relevant articles and documents
Highly β-regioselective Friedel-Crafts aminoalkylation of pyrroles with cyclic perfluoroalkylated imines
Shmatova, Olga I.,Shevchenko, Nikolay E.,Balenkova, Elisabeth S.,Roeschenthaler, Gerd-Volker,Nenajdenko, Valentine G.
, p. 3049 - 3058 (2013)
A Friedel-Crafts-type alkylation reaction was studied between various pyrroles and α-polyfluoroalkylated cyclic imines that were activated by Lewis acids. The reaction proceeded under mild conditions and provided a high yielding synthesis of α-CF3-substituted pyrrolidines and piperidines as well as seven-membered analogues that contained a pyrrole ring. The unpredictably high β-selectivity for the aminoalkylation of both 1H-pyrrole and N-substituted pyrrole was observed as a result of a thermodynamically-controlled electrophilic substitution reaction. The computational data are in full agreement with the experimental results, which confirmed the observed regioselectivity as a result of the lower energy of the β-substituted pyrroles that contain α-trifluoromethyl-substituted pyrrolidine, piperidine, and azepane rings. Trifluoromethyl-substituted cyclic imines were activated by various Lewis acids and underwent a reaction with pyrrole derivatives. An unpredictable β-selectivity was observed. The regioselectivity of the aminoalkylation was explained by computation data, which also confirmed the isomerization of the α isomer into the β isomer. Copyright
New method of preparation of C2F5Li and its reactions with cyclic imines and lactims: Synthesis of α-pentafluoroethyl proline
Shevchenko, Nikolay E.,Nenajdenko, Valentine G.,R?schenthaler, Gerd-Volker
, p. 390 - 396 (2008/12/21)
Addition of pentafluoroethyllithium to cyclic imines leads to pentafluoroethyl substituted pyrrolidines, piperidines and azepanes while reaction of cyclic lactims gives rise to 2-pentafluoroethyl imines. Oxidative cleavage of 2-furyl-2-pentafluoroethyl pyrrolidine has been found to be an effective method for the preparation of a racemic α-pentafluoroethyl proline.