Metal and Chloride Free Friedel-Crafts Acylation

This modification of the classical Friedel-Crafts acylation reaction still uses a stoichiometric amount of catalyst and generates the expected mixture of ortho and para substituted products, but it has the advantage that a carboxylic acid is used as the acylating component (rather than an acid chloride or anhydride), and the catalyst used is methanesulphonic anhydride (MSAA).  An added advantage is that in many cases no solvent is required as the substrate of acylation can be used as starting material and solvent.  If a solvent is required 3-4 volumes of toluene are used.  12 examples with yields varying from 53-87%.

M.C Wilkinson, Org. Lett., 2011, 13, 2232-2235.