[BPy]HSO4 as an Efficient and Recyclable Catalyst for One-Pot Synthesis of -Aminophosphonates under Solvent-Free Conditions

[BPy]HSO4 was prepared and used as an efficient and recyclable catalyst for the one-pot three-component synthesis of α-aminophosphonates at room temperature under solvent-free conditions with good-to-excellent yields. The workup procedure is very simple, and the catalyst can be reused at least four times without any loss in catalytic activity.