The enormous acidifying effect of the supersubstituent ᎐ ᎐ NSO 2 CF 3 on the acidity of derivatives of benzenesulfonamide and toluene-p- sulfonamide in the gas phase and in dimethyl sulfoxide

The effect of stepwise replacement of ᎐ ᎐ O oxygen atoms by ᎐ ᎐ NSO 2 CF 3 fragments in the sulfonyl group of toluenep-sulfonamide and benzenesulfonamide on their acidity has been studied in the gas phase and dimethyl sulfoxide (DMSO). Incorporation of the first ᎐ ᎐ NSO 2 CF 3 group into 4-MeC 6 H 4 SO 2 NH 2 increases its gas-phase acidity by 23.6 kcal mol Ϫ1 . Substituting the second ᎐ ᎐ O by the ᎐ ᎐ NSO 2 CF 3 group leads to an additional acidity increase of 10.7 kcal mol Ϫ1 ; the total acidity increase is thus 34.3 kcal mol Ϫ1 (25 powers of ten!). In DMSO solution the total acidity increase is 13 pK a units (17.7 kcal mol Ϫ1 ). These findings are also supported by computational studies using DFT B3LYP at the 6-31ϩG* level and the semiempirical PM3 method. The results of this work have potentially important implications for the design of new strongly acidic catalytic materials

Copper-Catalyzed Trifluoromethylation of Unactivated Olefins

Activating the inactive: A copper-catalyzed allylic trifluoromethylation of unactivated terminal olefins proceeds under mild conditions to produce linear allylic trifluoromethylated products with high E/Z selectivity (see scheme). The reaction can be applied to a range of substrates bearing numerous functional groups. Furthermore, the reaction is scalable and amenable to a benchtop setup.National Institutes of Health (U.S.) (GM46059)National Institutes of Health (U.S.) (Postdoctoral Fellowship F32GM093532)National Science Foundation (U.S.) (Grant ACHE-9808061)National Science Foundation (U.S.) (Grant DBI-9729592)National Institutes of Health (U.S.) (Grant 1S10RR13886-01