Cu‐Catalyzed C(sp2−H)‐Trifluoromethylation of Aldehyde Hydrazones with Langlois Reagent

Abstract

AbstractThe C(sp2−H)‐trifluoromethylation of hydrazones would give access to the α‐trifluoromethylated hydrazones that can serve as intermediates in the synthesis of pharmaceutically interesting fluorinated compounds. Herein, we demonstrate the Cu‐catalyzed C(sp2−H)‐trifluoromethylation of the aldehyde hydrazones using the readily available and cost effective Langlois reagent (sodium trifluoromethanesulfinate). This reaction is broadly applicable to a series of aromatic aldehyde N‐aminomorpholine hydrazones to give the corresponding C(sp2)‐trifluoromethyl hydrazones in moderate to high yields. The reaction generally tolerates a series of electron‐releasing as well as electron‐withdrawing substituents on the aromatic ring.