A new ground-state organic electron donor has been prepared that features four strongly π-donating iminophosphorano substituents on a bispyridinylidene skeleton. Cyclic voltammetry reveals a record redox potential of −1.70 V vs. saturated calomel electrode (SCE) for the couple involving the neutral organic donor and its dication. This highly reducing organic compound can be isolated (44 %) or more conveniently generated in situ by a deprotonation reaction involving its readily prepared pyridinium ion precursor. This donor is able to reduce a variety of aryl halides, and, owing to its redox potential, was found to be the first organic donor to be effective in the thermally induced reductive S[BOND]N bond cleavage of N,N-dialkylsulfonamides, and reductive hydrodecyanation of malonitriles.
- electron transfer
- organic reductants
- substituent effects
Hanson, S. S., Doni, E., Traboulsee, K. T., Coulthard, G., Murphy, J. A., & Dyker, C. A. (2015). Pushing the limits of neutral organic electron donors: A tetra(iminophosphorano)-substituted bispyridinylidene. Angewandte Chemie International Edition, 54(38), 11236-11239. https://doi.org/10.1002/anie.201505378