Rate constants for aryl radical cyclization of aldimines: Synthesis of tetrahydroisoquinolines by fast 6-endo closures to carbon

Article abstract of DOI:10.1016/0040-4039(92)88156-Y

Aryl radicals cyclize to an imino functional group in a competition involving 6-endo closure to C and 5-exo closure to N. there is a large 6-endo preference forming tetrahydroisoquinolinyl radicals with k(6-endo) (80°C) > 10⁸ s^-1.