“…[21][22][23][24][25][26][27][28][29][30][31][32][33][34] Elegant examples include an iron-mediated one-pot oxidative coupling by Knölker, 21,22,30,31 a radical cyclization by Crich and Rumthao, 32 and most recently, a one-pot domino benzannulation between indole-3-ynones and nitroalkanes by Mehta. 34 To complement these previously reported approaches to carbazole natural products, and encouraged by a recent total synthesis report utilizing a cyclobutanol ring expansion, 35 we were inspired to develop a strategy based on our previously developed cyclobutanol ring expansion methodology (Scheme 1, c). In 2018, we reported that heteroaromatic-substituted cyclobutanols undergo regioselective ring expansion to 4-tetralones by treatment with N-bromosuccinimide in acetonitrile.…”