Effect of temperature on 5-endo- and 4-exo-trig radical cyclizations of N-vinylic α-halo amides

Article abstract of DOI:10.1016/S0040-4039(97)10492-0

The radical 3a generated from N-vinylic trichloroacetamide 1a provided the 5-endo-trig cyclization product 2a in boiling toluene, whereas, at room temperature, gave the 4-exo-trig cyclization product 9. The results may be explained in terms of the reversi