Hybrid super electron donors – preparation and reactivity

Associate Editor: M. P. Sibi © 2012 Garnier et al; licensee Beilstein-Institut. License and terms: see end of document. Neutral organic electron donors, featuring pyridinylidene–imidazolylidene, pyridinylidene–benzimidazolylidene and imidazolyli-dene–benzimidazolylidene linkages are reported. The pyridinylidene–benzimidazolylidene and imidazolylidene–benzimidazolyli-dene hybrid systems were designed to be the first super electron donors to convert iodoarenes to aryl radicals at room temperature, and indeed both show evidence for significant aryl radical formation at room temperature. The stronger pyridinylidene–imidazolyli-dene donor converts iodoarenes to aryl anions efficiently under appropriate conditions (3 equiv of donor). The presence of excess sodium hydride base has a very important and selective effect on some of these electron-transfer reactions, and a rationale for this is proposed