Antiaromaticity Gain Activates Tropone and Nonbenzenoid Aromatics as Normal-Electron-Demand Diels–Alder Dienes

• Published in: Organic letters Vol. 22; no. 18; pp. 7083 - 7087
• Main Authors: Karas, Lucas J, Campbell, Adam T, Alabugin, Igor V, Wu, Judy I
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 18.09.2020
• Subjects: aromatic compounds; cycloaddition reactions; energy; hydrazones

We propose a carbonyl umpolung strategy for activating tropone as a normal-electron-demand Diels–Alder diene. Tropone has low reactivity for Diels–Alder reactions because of its [4n+2] π-aromaticity. Conversion of the carbonyl group into a hydrazone ion (N–NR–) reverses the polarity of the exocycli...