Process for the preparation of Michael-adducts

A process for the preparation of a compound of formula (III):

• wherein
• Q is selected from the group consisting of R′ and OR′ group;
• R1, R′, and R″ are selected, independently from each other, from the group consisting of a linear C1-C5 alkyl group, linear C1-C5 alkenyl group, a C1-C4 alkyl group, a C1-C4 alkenyl group, a C1-C4 alkoxy group, a C5-C6 cycloalkyl group, and a cycloalkenyl group;
• R′″ is selected from the group consisting of a hydrogen atom, and a linear or branched C1-C3 alkyl group;
• and
• R2, R3, and R4 are selected, independently from each other, from the group consisting of a hydrogen atom, a linear C1-C5 alkyl group, a linear C1-C5 alkenyl group, a C1-C4 alkyl group, a C1-C4 alkenyl group, a C1-C4 alkoxy group, a C5-C6 cycloalkyl group, and a C5-C6 cycloalkenyl group;
• wherein at least two of said R2, R3 and R4 groups do not represent simultaneously an hydrogen atom;
• which comprises reacting a β,β- or a α,β-disubstituted, or a α,β,β-trisubstituted, α,β-unsaturated ketone (I)
• wherein R1, R2, R3 and R4 have the same meaning as in formula (III), with a β-ketoester or a β-diketone (II)
• wherein Q, R″ and R′″ have the same meaning as in formula (III),
• in the presence of a catalyst of formula M(X)n, wherein
• M is selected from the group consisting of a 3d transition metal, a lanthanide, a trimethylsilane group, a vanadyl group, an alkaline metal, Sc, Y, Sn, Pb, Al and Bi;
• n is an integer from 1 to 3;
• and
• X is selected from the group consisting of CF3SO3−, RSO3−, SbF6−, PF6−, ClO4−, [BF3(RCOCRCOR)]−, [BF3(RCOCRCO2R)]−, [BF3(RCOO)]−, [BF3(RO)]−, and BF4−, with R selected from the group consisting of an C1-C10 aromatic, alkylaromatic or alkyl group, halides atoms, and C1-C6 alkyl or alkoxy groups.