The Diaza[5.5.6.6]fenestrane Skeleton—Synthesis of Leuconoxine Alkaloids

Abstract

Among the Aspidosperma-derived monoterpene indole alkaloids, the leuconoxine subgroup has drawn significant attention from the synthetic community during the past few years. This Minireview summarizes the hitherto six completed total syntheses of leuconoxines emphasizing the different strategies for assembling the key structural motif, an unprecedented diaza[5.5.6.6]fenestrane skeleton. In addition, the proposed biogenetic relationships within the group of these alkaloids are described.

Pd-Catalyzed Aerobic Oxidative Heck Cross-Coupling for the Straightforward Construction of Indole δ-Lactams

“…The leuconoxine subfamily of aspidosperma-derived monoterpene indole alkaloids (e.g., 1 – 8 in Figure 1) was isolated from the plants of the genus Leuconotis ( Apocynaceae ) (Pfaffenbach and Gaich, 2016, Geng et al., 2016, Tokuyama, 2015). These natural products possess a unique diaza-[5.5.6.6]-fenestrane structural motif that is extremely rare in indole natural products.…”

Synthesis of indole derivatives as prevalent moieties present in selected alkaloids

“…(À)-Mersicarpine (110), 333 however, contains a fused tetracyclic 6/ 5/6/7 ring scaffold, identied by an unusual tetrahydro-2H-azepine ring and also a hemiaminal scaffold. [343][344][345][346] In 2019, Wang and co-worker reported 347 a unied approach for the asymmetric synthesis of (À)-scholarisine G ( 415), (+)-melodinine E (416), (À)-leuconoxine ( 417) and (À)-mersicarpine (110) from the 2alkylated indole intermediate. The total synthesis of (À)-scholarisine G ( 415), (+)-melodinine E (416), (À)-leuconoxine ( 417) and (À)-mersicarpine (110) began with o-toluidine (404).…”

Otto‐Bayer‐Preis: D. Trauner / Bayer Early Excellence in Science Award: T. Gaich / Cottrell‐Fulbright‐Preis: O. Vázquez / JSPS‐Preis: S. Kaskel

“…Gaich wurde in dieser Rubrik vorgestellt, als sie einen ADUC‐Preis erhalten hatte . Kürzlich hat sie in Chemistry—A European Journal die Synthese von Leuconoxin‐Alkaloiden beschrieben und die Konfiguration von Corynanthean‐Alkaloiden behandelt …”