Domino Reaction for the Synthesis of Polysubstituted Pyrroles and Lamellarin R

A three-component annulation reaction
was developed for the synthesis
of pyrroles, a class of compounds with various properties valuable
to biomedical and polymer industries. Treatment of α-silylaryl
triflates, Schiff bases, and alkynes generated polysubstituted pyrroles
in good yields (61–86%) with regioselectivity. This domino
reaction involved completion of five sequential steps in a single
flask, which comprised aryne formation through 1,2-elimination, their
alkylation by Schiff bases through 1,2-addition, 1,4-intramolecular
proton transfer, Hüisgen 1,3-dipolar cycloaddition, and dehydrogenative
aromatization. It was then successfully applied as the key step in
the synthesis of the natural product lamellarin R. This new reaction
represents an efficient, sustainable process for the production of
chemical materials.