Synthesis of Quinolinone Alkaloids via Aryne Insertions into Unsymmetric Imides in Flow
J. Schwan, M. Kleoff, B. Hartmayer, P. Heretsch, M. Christmann – 2018
A general strategy for the synthesis of 3,4-dioxygenated quinolin-2-one natural products is reported. The key step is a regioselective insertion of arynes into unsymmetric imides. When performed in continuous flow, the reaction proceeds within minutes, while lower yields and longer reaction times are observed in batch. The resulting N-acylated 2-aminobenzophenones were transformed to (±)-peniprequinolone, (±)-aflaquinolones E and F, (±)-6-deoxyaflaquinolone E, (±)-quinolinones A and B, and (±)-aniduquinolone C in 1−3 steps.