Abstract: A method for preparing bismuth tris-trifluoromethanesulphonate, characterized in that it consists in reacting CF3SO3H trifluoromethanesulphonic acid with Bi2O3 bismuth trioxide in a medium consisting of a water/alcohol mixture, and in recuperating the resulting bismuth tris-trifluoromethanesulphonate.

Abstract: The present invention relates to a bismuth-type promoter and its use as a Lewis acid catalyst for acylation reactions of aromatic compounds. The promoter corresponds to the formula MY&mgr;−q&xgr;q, where M represents a &mgr;-valent and at least trivalent element in the cationic form, preferably known to give Lewis acids, where Y is a monovalent anion or a monovalent anionic functional group, where &xgr;− represents an anion or an anionic functional group carrying a sulfonyl functional group carried by a perhalogenated atom, preferably a perfluorinated atom, more preferably a perfluoromethylene (—CF2—); and where q is an integer advantageously chosen within the closed range (comprising the limits) ranging from 1 to (&mgr;−1) (that is to say, 1 or 2 when &mgr; is 3). The present application also relates to processes for the preparation of the promoter.

Abstract: A subject-matter of the present invention is a process for the sulfonation of an activated or deactivated aromatic compound. The invention applies to the preparation of aromatic sulfones. The process for the sulfonation of an aromatic compound according to the invention comprises the reaction of said aromatic compound with a sulfonating agent, in particular an aryl or alkyl sulfonating agent, in the presence of a catalytically effective amount of a mixture of a bismuth trihalide and of perfluoroalkanesulfonic acid.