One-pot multicomponent synthesis of highly substituted piperidines using p-toluenesulfonic acid monohydrate as catalyst

Article abstract of DOI:10.1007/s00706-011-0671-7

β-Toluenesulfonic acid monohydrate (p-TsOH-H₂O) is a highly effective and efficient catalyst for the one-pot multicomponent coupling of aldehydes, amines, and β-ketoesters in EtOH at ambient temperature to give highly functionalized piperidines in high yields. This one-pot reaction has some important advantages such as the easy workup procedure, simple and readily available precursors, nontoxic and inexpensive catalyst, and good to high yields. Springer-Verlag 2011.