Super-Electron Donors:  Bis-pyridinylidene Formation by Base Treatment of Pyridinium Salts

Abstract

Deprotonation of bispyridinium salt 7b affords bispyridinylidene 10, a very powerful neutral organic two-electron donor [E1/2 (DMF)=-1.13 V vs Ag/AgCl/KCl (sat)], presumably via the pyridinylidene 8. Donor 10 reduces aryl iodides and bromides to aryl anions in excellent yield and also reductively cleaves selected phenylalkylsulfones very efficiently.