Synthesis of an indole analog of magallanesine via the [1,2]-meisenheimer rearrangement

Ring expansion of azetopyridoindole 11 via the [1,2]-Meisenheimer rearrangement of the corresponding N-oxide 12 gave azocinoindole 14 , which was converted into the N-benzoylenaminone 18 in 5 steps. Intramolecular cyclization of 18 was accomplished by a modified Heck reaction followed by reductive desulfonylation to provide the indole analog 2, 5H -isoindolo[2′,1′;1,2]azocino[5,6-b]indole, of magallanesine 1 .