Pushing the limits of neutral organic electron donors: a tetra(iminophosphorano)-substituted bispyridinylidene

Samuel S Hanson; Eswararao Doni; Kyle T Traboulsee; Graeme Coulthard; John A Murphy; C Adam Dyker

doi:10.1002/anie.201505378

Pushing the limits of neutral organic electron donors: a tetra(iminophosphorano)-substituted bispyridinylidene

Angew Chem Int Ed Engl. 2015 Sep 14;54(38):11236-9. doi: 10.1002/anie.201505378. Epub 2015 Jul 24.

Authors

Samuel S Hanson¹, Eswararao Doni², Kyle T Traboulsee¹, Graeme Coulthard², John A Murphy³, C Adam Dyker⁴

Affiliations

¹ Department of Chemistry, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3 (Canada).
² WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL (UK).
³ WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL (UK). john.murphy@strath.ac.uk.
⁴ Department of Chemistry, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3 (Canada). cadyker@unb.ca.

Abstract

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N bond cleavage of N,N-dialkylsulfonamides, and reductive hydrodecyanation of malonitriles.

Keywords: electron transfer; iminophosphoranes; organic reductants; reduction; substituent effects.

© 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.