Amination, III. Trimethylsilanol as Leaving Group, V. Silylation—Amination of Hydroxy N‐Heterocycles

Abstract

Abstract Hydroxy N‐heterocycles such as 18 , 21 , 26 , and others are efficiently aminated in a one‐step/one‐pot procedure by silylation‐amination to give 20 , 23 – 25 etc. Silylation converts aromatic hydroxy N‐heterocycles into activated and lipophilic intermediates of type 3 , 8 which react in situ with ammonia, primary or secondary amines to form the corresponding mono‐, bis‐ or tris‐aminated products ( 5 , 10 ). This addition‐elimination of amines to O ‐silylated heterocycles in Lewis acid‐catalyzed and proceeds usually in high yields if the leaving group trimethylsilanol is converted in situ by excess silylated agent into hexamethyldisiloxane. Scope and limitations of this simple procedure are discussed.