The road less traveled: New chemistry of old reactive intermediates

Conditions were optimized to utilize benzyl alcohol and acetate substrates in Friedel-Crafts electrophilic aromatic substitution reactions. Anhydrous iron (III) chloride (20 mol%) was shown to be an efficient catalyst when using benzene in a microwave reactor. Rapid reactions and minimal further purification make this procedure suitable for chemical library generation. We attempted to develop a synthetic route to the little known intermediate, ortho-xylallene. Though work to date has been unsuccessful, we have determined that traditional routes via allene formation may be viable. Rearrangements of terphenyls, phenyl-naphthalene, and 1,1\u27-binaphthalene by ipso-arenium cations were studied using triflic acid in 1,2-dichloroethane. Preferred formation of meta products appears to be the result of low energy cations involved in rearrangement. Formation of Scholl-type products under these conditions provides evidence for a closely related carbocationic mechanism for the Scholl Reaction