Shuhei Manabe, Curt M. Wong, C. Sevov
Jan 16, 2020
Citations
0
Influential Citations
46
Citations
Journal
Journal of the American Chemical Society
Abstract
The direct and scalable electroreduction of triphenylphosphine oxide (TPPO) - the stoichiometric byproduct of some of the most common synthetic organic reactions - to triphenylphosphine (TPP) remains an unmet challenge that would dramatical-ly reduce costs and waste associated with performing desirable reactions that are mediated by TPP on large scale. This report details an electrochemical methodology for the single-step reduction of TPPO to TPP using an aluminum anode in combina-tion with a supporting electrolyte that continuously regenerates a Lewis acid from the products of anodic oxidation. The re-sulting Lewis acid activates TPPO for reduction at mild potentials and promotes P-O over P-C bond cleavage to selectively form TPP over other byproducts. Finally, this robust methodology is applied to (i) the reduction of synthetically useful classes of phosphine oxides, (ii) the one-pot recycling of TPPO generated from a Wittig reaction, and (iii) the gram-scale reduction of TPPO at high concentration (1 M) with continuous product extraction and in flow at high current density.