abstract |
A process is proposed for producing acyloines of general formula (I) in which Ra and Rb are identical or different and represent hydrogen or a C1-C20 alkyl, a C6-C10 aryl, a C7-C12 aralkyl, a heteroaryl, or a heterocycloalkyl group, these groups being substituted if appropriate, with the exception of formaldehyde autocondensation products. In the proposed process, an aldehyde of formula (II) RaCHO is allowed to react with an aldehyde of formula (III) RbCHO, in which Ra and Rb have the meanings indicated above and at least one of the groups Ra and Rb represents a group other than hydrogen, in the presence of catalysts produced using an auxiliary base from triazolium salts of formula (IV) in which R1 and R3 are identical or different and represent aliphatic groups with 1-30 carbon atoms, or, if appropriate, aryl groups, aralkyl groups and/or heteroaryl groups, these groups being substituted if appropriate; R2 represents hydrogen or the group RbCH(OH); and A is the equivalent of a singly or multiply negatively charged anion for the electrical neutralisation of the triazolium cation charge. |