Abstract
The high abundance of C–H bonds in organic molecules makes C–H functionalization a
powerful approach to quickly increase the complexity of an organic molecule. However,
the high abundance of C–H bonds also provides a challenge to C–H functionalization
reactions: selectivity. While most C–H functionalization reactions produce mixtures
of different products for most substrates, we have developed a highly selective method
for aromatic C–H functionalization via sulfonium salts. The reaction does not require
a certain directing group to be selective. The introduced functional group is a sulfonium
group, which participates in various follow-up reactions such as palladium-catalyzed
cross-coupling reactions and photoredox catalysis. Here we discuss our pathway to
develop the reaction as well as its scope and utility.
1 Introduction
2 Site-Selective Synthesis of Sulfonium Salts
3 Sulfonium Salts in Palladium-Catalyzed Cross-Coupling
4 Sulfonium Salts in Photoredox Catalysis
5 Sulfur(IV) Reductive Elimination
6 Cine Substitution
7 Conclusion
Key words
C–H functionalization - selectivity - sulfonium salts - cross-coupling - photoredox
catalysis
