On the mechanism of the intramolecular samarium barbier reaction. Probes for formation of radical and organosamarium intermediates

Article abstract of DOI:10.1016/S0040-4020(97)00608-X

A new type of mechanistic probe for the intramolecular samarium Barbier reaction has been designed, and two different probe substrates have been investigated in detail. Remarkably, no unambiguous evidence could be obtained in favor of any of the obvious intermediates (free alkyl or alkoxy radicals, ketyls, organosamarium species) that are postulated for this reaction. Several possibilities for modified mechanisms are suggested.