Ligand Exchange Reaction of Ferrocene with Heterocycles

Abstract

The ligand exchange reaction with heterocycles containing nitrogen, oxygen or sulfur atoms was carried out. For the reaction with heterocycles, the order of the reactivity was S-heterocycles > N-heterocycles > O-heterocycles. Furthermore, when the results for the heterocycles were compared to those for the corresponding hydrocarbons, the hydrocarbons had a higher reactivity. These results mean that the reactivity would be mainly governed by the electron density of these arenes.

Microwave Irradiation Effect on the Ligand Exchange Reaction between Ferrocene and Heterocycles

“…Under conventional heating conditions, the reaction with benzothiophene proceeds, but the reactions with the other bicyclic heterocycles do not proceeds [5].…”

“…Since the amount of ferrocene has decreased even in the reaction of the bicyclic compounds in which no product was obtained, the first step was expected to be accelerated by the microwaves even in this system. However, since the exchange product is very unstable in such a system [5], the transition state of the second step containing the coordination of the arenes to the [Cp-Fe] + would have a high energy. Therefore, the second step becomes rate-determining, so the reaction would not be accelerated by the microwaves (Figure 1).…”

Recent advances on carbazole-based photoinitiators of polymerization

“…The 3-and 6-positions of carbazole can also be eas ily functionalized with various groups such as aldehyde, halogens and nitro groups so that an extension of conjugation or the introduction of various groups can be carried out. Parallel to the modification of the carbazole core, carbazole is also an electron-rich polyaromatic group that can be used for the design of ferrocenium salts, these iron complexes being prepared by ligand exchange on ferrocene [91].…”