SYNTHESIS OF BENZOFURANS, INDOLES AND BENZOPYRANS VIA OXIDATIVE FREE RADICAL CYCLISATIONS USING COBALT SALEN COMPLEXES.

Article abstract of DOI:10.1016/S0040-4039(00)84514-1

Reactions between the Co(I) species derived from cobalt(III) 'salen'(1), and (O-allyl) or (O-but-3-enyl)iodophenol, leads to isolatable cobalt complexes, viz (2), (13), which can be converted into substituted benzofurans, i.e. (5), (6) and benzopyrans, i.e. (14), (15); similarly interaction between (18) and Co(I) 'salen' led, in one step, to the 3-methylindole (19).