Chemistry Reference
In-Depth Information
Thiophenes
John Arthur Joule
Abstract The structure and principal chemical reactivities of thiophenes are
briefly introduced.
Keywords Aromaticity
Bromination
Diels-Alder reaction
Electrophilic
substitution
Furan
Indophenine
Isatin
Metallation
Palladium(0) catalysis
Pyrrole
S-oxidation
Sulfur lone pair
Thiophene numbering
Viktor Meyer
π
-System
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Thiophene Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3 Thiophene Substitution Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4 Thiophene Metallation ......................................................................... 4
References .......................................................................................... 5
1
Introduction
The simple thiophenes are stable liquids that closely resemble the corresponding
benzene compounds in boiling points and even in smell. The discovery of thiophene
in coal tar benzene provides one of the classic anecdotes of organic chemistry. In
the days when colour reactions were essential for diagnosis, benzene was identified
by the production of a blue colour on heating with a mixture of isatin (1
-indole-
2,3-dione) and concentrated sulfuric acid. In 1882, during a lecture-demonstration
H
