Chemistry in superacids. 8. Superacid-catalyzed carbonylation of methane, methyl halides, methyl alcohol, and dimethyl ether to methyl acetate and acetic acid

Superacid-catalyzed (BF, BF3-H2O, HF-BF3, and CF3SO3H) carbonylation of methane and its substituted derivatives (particularly, methyl alcohol and dimethyl ether) gave acetic acid and methyl acetate. HF-BF3 was found to be the most effective catalyst, giving nearly complete conversion of methyl alcohol or dimethyl ether. CF3SO3H led to lower yields and also to the formation of methyl trifluoromethanesulfonate. Possible reaction pathways and mechanisms are discussed on the basis of experimental results. Contrasted with Rh-catalyzed carbonylation of methyl alcohol, the superacid-catalyzed reaction does not necessitate expensive catalyst and conditions necessary with sensitive organometallic catalyst systems.