FUNCTIONALIZATION OF SATURATED-HYDROCARBONS .3. ONE-STEP ALKYLACYLATION OF AROMATIC-HYDROCARBONS WITH ALKANES (OR CYCLOALKANES) IN THE PRESENCE OF APROTIC ORGANIC SUPERACIDS

Alkanes and cycloalkanes (isobutane, butane, isopentane, isohexane, and methylcyclopentane) react with benzene or bromobenzene at 0-20-degrees-C in the presence of RCO+Al2X7- complexes (R = Me, Pr, or Ph; X = Cl or Br) to give products of the alkylacylation of arenes. The yields of alkylated aromatic ketones reach 60-87 % in 5-30 min, whereas the yields of unalkylated aromatic ketones (the competitive reaction) reach 0-40 %. The reactions of isobutane or isopentane with benzene result exclusively in para isomers of t-BuC6H4COR or a mixture of Me2(Et)CC6H4COR and Me(i-Pr)CHC6H4COR isomers (1:1), respectively. The reaction of isobutane with benzene also proceeds regioselectively and gives only one isomer, 2-Br-t-BuC6H4COR.