posted on 2023-11-08, 16:35authored byJohn Kornfeind, James E. Allen, Taylor M. Keller, Fraser F. Fleming
SiCl4 promotes isocyanide
additions to oxoalkenenitriles
to selectively generate 3-acylpyrroles, 2-aminofurans, or pyrrolidinones.
Cyclic oxoalkenenitriles add 2 equiv of an isocyanide that installs
the two core atoms of an acylpyrrole and a nitrile substituent, whereas
acyclic oxoalkenenitriles add 1 equiv of an isocyanide to afford 2-aminofurans;
subsequent air oxidation generates pyrrolidinones via a furan oxygenation–cleavage–cyclization
sequence. The syntheses proceed under mild conditions to rapidly access
three richly decorated heterocycles.