Abstract
Silyl esters have been exploited as metastable reaction intermediates, both purposefully
and unintentionally, since at least the 1960s. Their reactivity is broadly related
to the substituents on the silicon, and in this way their properties can be readily
modulated. Silyl esters have unique reactivity profiles that have been used to generate
downstream products of a range of functionalities, and because of this many excellent
methods for the synthesis of a variety of value-added chemicals have been developed.
Furthermore, because of the frequent use of hydrosilanes as terminal reductants in
catalytic processes, silyl ester intermediates are likely more commonly utilized by
synthetic chemists than currently realized. This review comprehensively summarizes
the reactions known to take advantage of reactive silyl ester intermediates and discusses
examples of catalytic reactions that proceed in an unanticipated manner through silyl
ester intermediates.
1 Introduction
2 Synthesis of Silyl Esters
3 Making Amides from Silyl Esters
3.1 Amidation Using Chlorosilanes
3.2 Amidation Using Azasilanes
3.3 Amidation Using Oxysilanes
3.4 Amidation Using Hydrosilanes
3.5 Amine Formation via Amidation/Reduction
3.6 Miscellaneous
4 Mechanistic Investigations of Amidation
4.1 Mechanism of Amidation Using Chlorosilanes
4.2 Mechanism of Amidation Using Hydrosilanes
4.3 Mechanism of Amidation Using Oxy- or Azasilanes
5 Making Esters from Silyl Esters
6 Making Aldehydes, Alcohols, Amines, and Alkanes via Reduction
6.1 Aldehyde Synthesis by Metal-Free Reduction
6.2 Aldehyde Synthesis by Metal-Mediated Reduction
6.3 Alcohol Synthesis by Metal-Mediated Reduction
6.4 Amine Synthesis
6.5 Alkane Synthesis by Metal-Free Reduction
7 Making Acid Chlorides from Silyl Esters
8 In Situ Generated Silyl Esters and Ramifications for Catalysis
9 Conclusion
Key words
silyl ester - carboxylic acid - organosilanes - amidation - reduction
