Synthesis of 7,8-Dimethoxy-2-oxo-1,3,4,5-tetrahydropyrrolo[4,3,2-de]quinoline: A Key Intermediate en Route to Makaluvamines, Discorhabdin C and Other Marine Alkaloids of this Group via Vicarious Nucleophilic Substitution of Hydrogen

Recent developments in indole ring synthesis—methodology and applications

“…Makosza has used this method to synthesize a series of N-hydroxyindoles and indoles, 216 and to prepare several pyrrolo[4,3,2-de]quinolines for use in the synthesis of the marine pyrroloiminoquinone alkaloids (Scheme 56). 217, 218 The selectivity observed in the nitro group reduction is noteworthy; shorter reduction periods lead to the cyanoquinolone, indicating that the less hindered nitro group is reduced first.…”

Simple indole alkaloids and those with a nonrearranged monoterpenoid unit (July 1997 to December 1998)

“…123 A new synthesis of makaluvamines A, D, I and K starting from 6-methoxyindole has been reported. 124 Intermediates for the synthesis of makaluvamines, discorhabdin C and related marine alkaloids has been synthesised by way of vicarious nucleophilic substitution, 125 intramolecular cyclization of 3-(azidoethyl)indoles 126 and hetero Diels-Alder reaction of indoloquinones. 127 A model compound has been prepared for the synthesis of wakayin.…”

Reductive Monoalkylation of Aromatic and Aliphatic Nitro Compounds and the Corresponding Amines with Nitriles

“…The use of a transfer hydrogenation procedure appeared to be much faster compared to direct reduction with hydrogen over palladium or other types of catalysts. Indeed, there were a number of reports of intramolecular nitrile-mediated reductive alkylations that have been conducted with hydrogen as a reductant at various pressures and over various types of catalysts. − Also, using active rhodium catalysts, Galan et al have demonstrated direct reductive coupling of aliphatic nitriles to form the corresponding secondary amines in high yield. In these instances, direct reduction of nitrile led to the corresponding amine, which then reacted with nitrile leading to a secondary amine product in a process likely identical to that reported here.…”