Total Synthesis of Lavendamycin by a [2+2+2] Cycloaddition

Abstract

The total synthesis of the bacterial-derived, pentacyclic, antitumor antibiotic lavendamycin has been achieved through a highly convergent strategy. The key step of this synthesis is a ruthenium-catalyzed [2+2+2] cycloaddition of an electrondeficient nitrile to an alkynyl-ynamide to prepare the carboline scaffold. The elaborate cycloaddition substrate is ob-

1,4,9,12-Tetramethoxy-14-octyl-5,8-dihydrodiindolo[3,2-b;2′,3′-h]carbazole with an unknown solvent

“…Among the different synthetic routes (Vlasselaer & Dehaen, 2016), the twofold Cadogan reaction (Cadogan et al, 1965) is a very successful route to indolocarbazoles (Kistenmacher & Mü llen, 1992;Wrobel et al, 2013) and is also suitable for the preparation of higher oligomers (Srour et al, 2016). In a continuation of our studies on indolo-annulated heterocycles (Dassonneville et al, 2011;Nissen & Detert, 2011;Letessier & Detert, 2013), we present here the first X-ray structure of a linear diindolocarbazole (Fig. 1).…”

1,4-Dihexyloxy-2,5-bis(2-nitrophenyl)benzene

“…1,4-Dihexyloxy-2,5-bis(2-nitrophenyl)benzene Norma Wrobel, Dieter Schollmeyer and Heiner Detert Comment As part of a larger project on the synthesis of carbazoles and heteroanalogous carbazoles (Letessier et al 2011, Dassonneville et al 2011, Nissen & Detert 2011, Letessier & Detert 2012) the Cadogan reaction (Cadogan 1962) appeared to be a suitable method for the construction of larger planar π-systems for optoelectronic applications …”

“…For the synthesis of carbazoles and heteroanalogous carbazoles, see: Letessier et al (2011); Dassonneville et al (2011); Nissen & Detert (2011); Letessier & Detert (2012). For the Cadogan reaction, see: Cadogan (1962).…”

Synthesis of quinolinequinone derivatives and related carbocyclic compounds

“…For a long time, they have been in the focus of a large number of studies because of their wide spectrum of biological activities, which include potent antifungal, antibacterial [1], antimalarial [2] and antineoplastic [3] properties. They are also an important structural moiety in a number of more complex antibiotic agents such as streptonigrin 2 [4], streptonigrone 3 [5] and lavendamycin 4 [6] as they play an important role in determining their biological activities [7]. The general structure of quinolinequinones 1 has been modified at various positions, and the synthesis and biological activities of various substituted quinolinequinones have been reported, often prepared by the regioselective nucleophilic substitution of 6,7-dichloro-5,8-quinolinequinone with arylamines ( Figure 1).…”