A novel approach to the indoloquinoline alkaloids cryptotackieine and cryptosanguinolentine by application of cyclization of o-vinylsubstituted arylheterocumulenes

Solvatochromic study of three indoloquinoline derivatives: Effect of chloro group/s on the photophysics of thecompounds

“…Other methods for synthesizing these compounds include cyclization of o-vinyl substituted arylheterocumulenes, Suzuki-coupling to a phenylquinoline followed by deprotection of the amino moiety and formation of an azide, which at higher temperature (via formation of a nitrene) undergoes ring closure, etc. [6,7]. Many such alkaloids are known to intercalate in the DNA double helix resulting in dramatic changes in DNA conformation and, furthermore, they can also inhibit DNA replication and transcription [8].…”

“…Innovative synthetic methods have been developed to get these natural products as anti-cancer agents. Reports are there about elegant microwave-assisted synthesis of cryptotackieine and cryptosanguinolentine, based on a divergent approach for the generation of the key 1-methyl-(o-azidophenyl)-quinoline-2-one followed by its selective indolization [6,13]. Fascination for cryptosanguinolentine has been growing with time because of the anti-cancer and antitumor properties of the compound and its derivatives.…”

Six‐Membered Heterocycles: Quinoline and Isoquinoline

“…In 1996 two groups [22] independently reported the isolation of cryptotackieine (13) and cryptosanguinolentine (14), two new alkaloids extracted from Cryptolepis sanguinolenta, a shrub indigenous to tropical West Africa. Cryptotackieine 13 displays a strong antiplasmodial activity against Plasmodium falciparum chloroquine-resistant strains, and both compounds display various interesting biological properties [23]. 17 Pyranoquinoline alkaloids are another important group of quinoline derivatives.…”

“…However, some of the most important examples are the pharmacologically active compounds, including several antimalarial drugs based on the quinine parent, for example, chloroquine (20) [27] and mefloquine (21) [28], and some antibacterial fluoroquinolones such as ciprofloxacin (22) [ In recent years some quinoline derivatives have attracted considerable interest for various pharmacological targets. For example, irinotecan (23) is an anticancer drug marketed by Pfizer [30], whereas L-689,560 (24) is a strong NMDA receptor antagonist identified by the Merck group. Overactivation of the NMDA subtype of excitatory amino acid receptors is implicated in several neurodegenerative disorders, including epilepsy, stroke, and Alzheimers disease [31].…”

Recent progress in the synthesis of heterocyclic natural products by the Staudinger/intramolecular aza-Wittig reaction

“…43 Treatment of 57 with tri-(n-butyl)phosphine in o-xylene at room temperature followed by heating at reflux temperature for 24 h gives 49 in only 5% yield; treatment of 57 with trimethylphosphine at room temperature followed by heating in nitrobenzene at reflux for 24 h affords 49 in 24% yield; further improvement up to 40% yield is achieved by microwave irradiation (Scheme 17). …”