Ambiphilic molecules for trapping reactive intermediates: interrupted Nazarov reaction of allenyl vinyl ketones with Me2PCH2AlMe2.
The addition of the ambiphilic molecule Me(2)AlCH(2)PMe(2) (1) to the allenyl vinyl ketone 2 gave a trapped Nazarov reaction product. Under kinetic control, the addition of the phosphine was on the methylated carbon, contrary to expected steric and electronic considerations. Computational data pointed to hydrogen bonding between the phosphine and the methyl group guiding the regiochemistry of this reaction. This product rearranged to provide the expected, regioisomeric Nazarov product. With additional 1 this compound yielded a Michael-addition product via a retro-Nazarov process.
Département de Chimie and Centre de Recherche sur la Catalyse et les Interfaces (CERPIC), Université Laval, 1045 Avenue de la Médecine, Québec, Québec, Canada G1V 0A6.
Josée
J
Boudreau
Marc-André
MA
Courtemanche
Vanessa M
VM
Marx
D
D
Jean Burnell
Frédéric-Georges
FG
Fontaine