One-Shot Double Amination of Sondheimer–Wong Diynes: Synthesis of Photoluminescent Dinaphthopentalenes

Photoluminescent diamino-substituted dinaphtho­pentalenes were synthesized successfully by the treatment of in situ prepared dinaphtho­cyclo­octadiyne with lithium amide. This reaction involves a series of transformations including the nucleophilic addition of the lithium amide to a triple bond of the cyclooctadiyne moiety, transannulation, protonation of the resulting pentalene anion, and the nucleophilic substitution of the pentalene core with the lithium amide. In this procedure, a novel double amination step plays a key role. When the diamino-substituted dinaphtho­pentalenes were irradiated with UV light in toluene, fluorescence was observed at around 580 nm (ΦF < 0.03).