Trifluoromethyl N-acylhydrazones: A versatile trifluoromethyl building blocks for construction of trifluoromethylated nitrogen-containing compounds

Trifluoromethyl group (CF3) is a privilege scaffold in fluorine-containing drugs, agrochemicals and material science. Hence, the development of highly efficient methods for introducing trifluoromethyl group into organic molecules is of primary importance. Significant progress on trifluoromethylation strategies, including trifluoromethylation reagents and trifluoromethyl building blocks, has been made in past two decades. Among various trifluoromethylation methods, trifluoromethylation by using the trifluoromethyl building blocks has always played an important role. As a stable and easily available compounds, trifluoromethyl N-acylhydrazones have emerged into versatile trifluoromethyl building blocks for construction of trifluoromethylated nitrogen compounds, especially for trifluoromethyl nitrogen-heterocycles. This review gives an overview on the research progress to use trifluoromethyl N-acylhydrazones as trifluoromethyl building blocks for construction of trifluoromethyl compounds.