Selective Synthesis of Secondary Amines with Cu(OH)_x/Al₂O₃

Significance

Aluminum-supported copper hydroxide Cu(OH)_x/Al₂O₃ catalyzed the N-alkylation of primary amines 1, urea, or NH₃ with benzyl alcohols 2 in mesitylene to give the corresponding secondary amines in 70-98% GC yield (14 examples). The catalyst was recovered by simple filtration and reused without significant loss of activity for the formation of 3c (75 min, 75% GC yield).