Fig. 3: Experimental investigations of the isomerization of Friedel–Crafts products.
From: Leveraging long-lived arenium ions in superacid for meta-selective methylation
a Monitoring of the Friedel–Crafts methylation of acetanilide (monitored by 1H NMR analysis of aliquot samples of the reaction mixture). b Control experiments for the isomerization of 1p to 1m (monitored by 1H NMR analysis of aliquot samples of the reaction mixtures). c Isomerization of compounds 14, 19, 23, 29 (overall yield of the mixture of regioisomers; regioselectivity determined by NMR analysis of the crude product). d Attempt of intramolecular competition between the methylation of a C–H or a C–D bond after methyl migration from 1p-d. e KIE study through intermolecular competition and by separate experiments between two isotopologues 1p and 1p-d3 (kH/kD average values obtained from three experiments, see SI).
