Synthetic Utility of the Vilsmeier–Haack Reagent in Organic Synthesis

Abstract The Vilsmeier–Haack reaction has historically been a topic of significant interest to organic chemists, and it continues to attract considerable attention. The reaction itself provides a facile route towards a large number of aromatic and heteroaromatic systems. The Vilsmeier–Haack reagent, generated from amides and halides, is found to be very important in organic synthesis. This account highlights recent developments in the synthetic utility of the Vilsmeier–Haack reagent. 1 Introduction 2 Formylation 3 Formylation and Chlorination 4 Formylation and Acetylation 5 Chlorination 6 ortho-Formylation 7 Miscellaneous 8 Conclusions