3-(Hetero)aryl-4-indolylamino-α-tetralones by diastereoselective internal redox cyclization: An "azaenamine" conjugate addition
(E)-3-(Hetero)aryl-1-(2-((E)-(indolin-1-ylimino)methyl)phenyl) prop-2-en-1-ones 1 undergo 6-exo-trig cyclization reactions upon treatment with BF3?Me2S in dichloromethane at low temperature to give the tetralones 10 in good yield. Th