Selective Iridium‐Catalyzed Alkylation of (Hetero)Aromatic Amines and Diamines with Alcohols under Mild Reaction Conditions

Abstract

Abstract Selective amine alkylation : A P,N‐ligand‐stabilized iridium complex has been used as an efficient catalyst for the alkylation of (hetero)aromatic amines with alcohols at mild reaction temperatures and catalyst loadings as low as 0.1 mol % Ir (see scheme). The excellent selectivity of the catalyst for monoalkylation of the amine function has also been exploited for the N , N ′‐dialkylation of diamines in both symmetric and nonsymmetric fashions. magnified image A P,N‐ligand‐coordinated iridium complex has been employed as an efficient catalyst for the selective monoalkylation of (hetero)aromatic amines with alcohols. A significant improvement of this alkylation method has been achieved, such that it can be performed at a temperature of 70 °C and with catalyst loadings as low as 0.1 mol % Ir, while still affording excellent yields of secondary amines. Furthermore, the high selectivity of this catalyst for the monoalkylation of aromatic amino functions has been successfully exploited for the alkylation of diamines in both symmetric and nonsymmetric fashions, providing a novel and very efficient synthetic tool for the preparation of N , N ′‐dialkylated aromatic diamines.