Electron transfer catalysis

The electron transfer catalysis is caused by electron transfer form of catalysis .

Reaction mechanism

A typical reaction scheme for electron transfer catalysis is as follows:

${\displaystyle \mathrm {(1)\ A+\ e^{-}\ \longrightarrow \ A^{\cdot -}} }$

${\displaystyle \mathrm {(2)\ A^{\cdot -}\ \longrightarrow \ B^{\cdot -}} }$

${\displaystyle \mathrm {(3)\ B^{\cdot -}+\ A\ \longrightarrow \ A^{\cdot -}+\ B} }$

The reaction can also take place via radical cations . The radical-nucleophilic substitution ( S _RN 1 ) of halogen aromatic compounds is an example of electron transfer catalysis. A halogen is replaced by a nucleophile via an intermediate free radical .

Sodium amide , alcoholates or enolates serve as nucleophiles . The reaction takes place in the following stages:

The term electron transfer catalysis was introduced analogously to acid-base catalysis and suggests that the electron behaves analogously to the proton . Since the electron acts more as a starter of a chain reaction , the term electron transfer-induced chain reaction was also proposed.

In electron transfer catalysis using organometallic catalysts , there is usually a change in the oxidation state of the metal involved.

Individual evidence

1. ↑ ^{a b} Entry on electron transfer catalysis . In: IUPAC Compendium of Chemical Terminology (the “Gold Book”) . doi : 10.1351 / goldbook.E02012 Version: 2.3.1.
2. ↑ Roberto A. Rossi: Phenomenon of radical anion fragmentation in the course of aromatic SRN reactions. In: Acc. Chem. Res. , 1982, 15 (6), pp. 164-170; doi : 10.1021 / ar00078a001 .
3. ↑ Jay K. Kochi: Electron-transfer mechanisms for organometallic intermediates in catalytic reactions. In: Accounts of Chemical Research. 7, 1974, pp. 351-360, doi : 10.1021 / ar50082a006 .