Unusual phenethylamine-containing alkaloids from Elaeocarpus tectorius

From the leaves of Elaeocarpus tectorius (Lour.) Poir. four previously undescribed phenethylamine-containing alkaloids were isolated, namely, tectoricine, possessing an unprecedented isoquinuclidinone ring system incorporating a phenethylamine moiety, tectoraline, representing a rare alkamide incorporating two phenethylamine moieties, and tectoramidines A and B, representing the first naturally occurring trimeric and dimeric phenethylamine alkaloids incorporating an amidine function. The structures of these alkaloids were established by detailed spectroscopic analysis. The absolute configuration of tectoricine was determined by comparison of the experimental and calculated ECD spectra. Plausible biosynthetic pathways to the four alkaloids are proposed.

Application of the aza-Diels–Alder reaction in the synthesis of natural products

The Diels–Alder reaction that involves a nitrogen atom in the diene or dienophile is termed the aza-Diels–Alder reaction.

Electrooxidative Cyclization of Hydroquinolyl Alcohols, Hydroquinolylamines, and Dimethyl Aminomalonates

Several hydroquinolyl alcohols and amines were electrochemically oxidized in methanol in the presence of sodium methoxide and potassium iodide to afford the corresponding intramolecular cyclization products. Furthermore, several amino malonates were electrochemically oxidized to yield the corresponding heterocyclic compounds through an intramolecular carbon–carbon bond formation in the presence of sodium cyanide in methanol.