Alkali metal reductions of organic molecules: why mediated electron transfer from lithium is faster than direct reduction.

Lithium metal reductions are widely employed in organic synthesis, where it is common to employ a "mediator" to speed up the electron transfer kinetics. We present experimental data for the electrode kinetics of the reduction of the most common mediator, 4,4'-di-tert-butyl-1,1'-b...

Full description

Bibliographic Details
Main Authors: Rees, N, Baron, R, Kershaw, N, Donohoe, T, Compton, R
Format: Journal article
Language:English
Published: 2008
Description
Summary:Lithium metal reductions are widely employed in organic synthesis, where it is common to employ a "mediator" to speed up the electron transfer kinetics. We present experimental data for the electrode kinetics of the reduction of the most common mediator, 4,4'-di-tert-butyl-1,1'-biphenyl (DBB) in tetrahydrofuran (THF) over a range of temperatures. Using corresponding data for the oxidation of lithium we present quantitative estimates of the kinetic advantage for the use of DBB as a mediator in lithium reductions, over, in particular, direct reduction using lithium metal.