Oxidative addition of trifluoroacetamide to alkenes, 2,5-dimethylhexa-2,4-diene and conjugated cyclic dienes

Trifluoromethanesulfonamide vs. Non-Fluorinated Sulfonamides in Oxidative Sulfamidation of the C=C Bond: An In Silico Study

A theoretical analysis of the reaction of oxidative sulfamidation of several alkenes was performed in order to explain the various experimental observations and different reactivity of triflamide and non-fluorinated sulfonamides. Transformations occurring in the system alkene–sulfonamide in the presence of oxidative system (Bu^tOCl + NaI) were analyzed at the MP2/DGDZVP//B3LYP/DGDZVP level of theory using the IEF-PCM method for taking into account the solvent acetonitrile (MeCN) effect. As the model substrates, styrene, trimethyl(vinyl)silane, dimethyl(divinyl)silane and diphenyl(divinyl)silane were chosen and mesylamide, triflamide, tosylamide and p-nosylamide were taken as the reagents. Bu^tOI generated from Bu^tOCl and NaI reacts with sulfonamides to give N-iodinated sulfonamides RSO₂NHI and RSO₂NI₂ as active intermediates, the iodinating activity of the latter being notably higher. The analysis allowed to answer such challenging questions as different reactivity of nonfluorinated sulfonamides leading to aziridination and of triflamide resulting in the formation the main products of bis-triflamidation, or different regioselectivity of halogenation of styrene and trimethyl(vinyl)silane caused by a linear intermediate iodonium cation in the former case and a cyclic one in the latter.

Oxidative addition/cycloaddition of arenesulfonamides and triflamide to N-allyltriflamide and N,N-diallyltriflamide

Mono- and diallyltriflamides react with triflamide in the oxidative system t-BuOCl + NaI to give the products of addition and cycloaddition, unlike the reaction of N-allyltriflamide with arenesulfonamides or trifluoroacetamide leading to chlorination and cyclodimerization.

Iodine-mediated regioselective synthesis of vinyl triflones from styrenes with CF3SO2Na

The iodine-mediated reaction of styrenes and CF₃SO₂Na proceeded regioselectively to give various potentially useful vinyl triflones.