Regio- and Stereoselective Electrophilic Cyclization Approach for the Protecting-Group-Free Synthesis of Alkaloids Lennoxamine, Chilenine, Fumaridine, 8‑Oxypseudoplamatine, and 2‑<i>O</i>‑(Methyloxy)fagaronine

A unified strategy
for protecting-group-free synthesis of alkaloids
lennoxamine, chilenine, fumaridine, 8-oxypseudoplamatine, and 2-O-(methyloxy)­fagaronine is reported. The core isoindolin-1-one
and isoquinolin-1-one structures were built by a silver-catalyzed
regio- and stereoselective cyclization of methyl 2-alkynylbenzimidates.
The regioselectivity of cyclization was achieved by utilizing the
intrinsic functionality of alkaloids.