N-Alkyl amines are extensively applied in the synthesis of functional materials, pharmaceuticals, and pesticides. The reaction of diols with amines is attractive and has been investigated for more than 30 years by using iridium, ruthenium, and other catalysts. However, the main products with diols as starting materials, especially for C₄–C₆ diols, are N-heterocyclic compounds because cyclization reaction is favorable in thermodynamics. Here, for the first time, a simple and non-noble catalyst CuNiAlO_x prepared by a coprecipitation method was developed for the reaction of C₄–C₆ diols with amines to give monoamination products. This method offers an efficient and environmentally friendly method for the selective monoamination of diols.