Domino Aldol-S[sub.N]Ar-Dehydration Sequence for [3+3] Annulations to Prepare Quinolin-2-ones

A domino aldol-S[sub.N]Ar-dehydration [3+3] annulation strategy has been utilized to fuse six-membered cyclic amides onto aromatic substrates. 2-Arylacetamides have been reacted with 2-fluorobenzaldehyde derivatives activated toward S[sub.N]Ar reaction by an electron-withdrawing substituent (NO[sub.2], CN, CF[sub.3], CO[sub.2]Me) at C5 to prepare 3,6-disubstituted quinolin-2(1H)-ones. Additionally, 3-substituted 1,8-naphthyridin-2(1H)-ones have been similarly derived from 2-fluoronicotinaldehyde. Fifteen examples are reported, and two possible mechanistic scenarios are presented and discussed.