Described is a concise total synthesis of (−)-ambiguine P, a cycloheptane-containing member of the hapalindole alkaloids. The challenging pentacyclic framework of the natural product was assembled rapidly via a [4 + 3] cycloaddition reaction-inspired strategy, and the tertiary hydroxy group was introduced by an NBS-mediated bromination–nucleophilic substitution sequence.

The asymmetric synthesis of (-)-N-methylwelwitindolinone B isothiocyanate is reported. Critical challenges overcome through these studies include the stereoselective installation of the sterically congested C13 alkyl chloride and control of the wayward reactivity of the indole unit to standard oxidants. A Pt-catalyzed hydrosilylation helped stymie unwanted rearrangements facilitated by vinyl group participation during the chloride installation step, and a new Fe -catalyzed oxidation accomplished the problematic conversion of indole into 2-indolinone.

The asymmetric synthesis of (−)‐N‐methylwelwitindolinone B isothiocyanate is reported. Critical challenges overcome through these studies include the stereoselective installation of the sterically congested C13 alkyl chloride and control of the wayward reactivity of the indole unit to standard oxidants. A Pt‐catalyzed hydrosilylation helped stymie unwanted rearrangements facilitated by vinyl group participation during the chloride installation step, and a new FeII‐catalyzed oxidation accomplished the problematic conversion of indole into 2‐indolinone.

The dearomative (4 + 3) cycloaddition reactions of 3-alkenylindoles with in situ-generated oxyallyl cations furnish cyclohepta­[b]­indoles, functionality-rich frameworks found in many bioactive compounds, including all pentacyclic ambiguine alkaloids. The analogous reactions between oxyallyl cations and 3-alkenylpyrroles afford cyclohepta­[b]­pyrroles. The cycloadducts are generally formed in good to high yields and diastereoselectivities and can be readily transformed into useful derivatives. Additionally, we report preliminary investigations into the enantioselective catalysis of the dearomative (4 + 3) cycloaddition using imidodiphosphorimidate catalysts.