Ruthenium Catalyzed N-Alkylation of Cyclic Amines with Primary Alcohols

Abstract

A robust alcohol amination protocol using common saturated amines and primary alcohols as starting materials is described. The reactions are catalyzed by combination of dichloro(p-cymene)ruthenium(II) dimer precatalyst with triphenylphosphine ligand, with the excess alcohol substrate or toluene functioning as the solvent. The catalyst and ligand residues can be precipitated from the reaction media by addition of hexane or cold diethyl ether, followed by precipitation and isolation of the product as a hydrochloride salt.