Facile synthesis of the azocino[4,3-b]indole framework of strychnopivotine and other Strychnos alkaloids

Abstract

A new synthetic route to the 1,5-methanoazocino[4,3-b]indole is described. The aim of the present study is to provide a tetracyclic skeleton for the synthesis of pentacyclic Strychnos alkaloids (tubifolidine and strychnopivotine). Starting from a carbazole derivative, the ring closure was achieved by an intramolecular aldol reaction. The final product was obtained in 45% in the overall yield over 7 steps.

The synthesis and spectroscopic characterization of (+)-demethoxyaspidospermine: Density functional theory calculations of the structural, electronic, and non-linear optic and spectroscopic properties

“…Both the synthesis and framework of this complex structure are critical and must be precisely determined. In the past, there have been reports of the syntheses of both aspidospermidine and strychnos-type alkaloids, [14][15][16][17] but the leading role of the intermolecular or intramolecular interactions on the challenging syntheses of this group of compounds has rarely been reported by using computational tools. [18][19][20] For this reason, we decided to investigate the structure, electronic, and spectroscopic properties of demethoxyaspidospermine because the results might provide useful information for synthetic chemists.…”

Recent Advances in the Synthesis of Hydrogenated Azocine-Containing­ Molecules

“…Uludag and co-workers ring-closed 1-oxo-1,2,3,4-tetrahydrocarbazole 325 by a NaH-promoted intramolecular aldol condensation to give the azocino[4,3- b ]indole system 326 (Scheme 96 ). 103…”

Green Synthesis of Pyrrole Derivatives Catalyzed by Molecular Sieves: DFT, ADMT, and Molecular Docking Investigations

“…[8] For this purpose, we designed and used molecular sieves, a natural compound we used in the previous alkaloid synthesis, for pyrrole synthesis in this study. [9] Compared to organic reagents, they are less dangerous and more environmentally friendly. Recently, we present new and useful methods for the construction of heterocyclic compounds using different catalysts.…”

“…The need to reduce the amount of toxic waste and by‐products generated in chemical processes requires the use of even less toxic and environmentally friendly materials when developing new synthetic methods [8] . For this purpose, we designed and used molecular sieves, a natural compound we used in the previous alkaloid synthesis, for pyrrole synthesis in this study [9] . Compared to organic reagents, they are less dangerous and more environmentally friendly.…”