2-Triazenyl furans are introduced as bench-stable, electron-rich Diels–Alder dienes, enabling convergent and divergent access to highly substituted arenes under redox-neutral conditions. The triazene substituent activates the furan toward cycloaddition, promotes in situ aromatization, and serves as a versatile handle for downstream functionalization. Diels–Alder reactions are demonstrated with a broad range of dienophiles, including alkenes, alkynes, allenes, and benzyne, in both inter- and intramolecular settings. Chemoselective derivatizations highlight the synthetic versatility of this platform, culminating in concise annulative syntheses of pomalidomide, (S)-apremilast, and related analogues.
Budwitz et al. (Mon,) studied this question.