Formation of grignard reagents from aryl halides: effective radical probes hint at a nonparticipation of dianions in the mechanism
We have prepared highly efficient radical probes 2a-b involving the hex-5-enyl rearrangement. The reaction of 2a-b with active magnesium leads to the cyclized products 4a-b, providing a direct evidence of radical intermediates during the formation of aryl Grignard reagents. The variations of yields for cyclized products 4a-b as a function of structural modifications in 2a-b suggest that the intervention of dianions is not necessary to explain the observed results.
Laboratoire AM3, ESA 6009, Universite Aix-Marseille III, case 561, 13397 Marseille Cedex 20, France.
N
Bodineau
JM
Mattalia
V
Thimokhin
K
Handoo
JC
Negrel
M
Chanon