Organocatalytic Synthesis of α-Aminophosphonates Using o-Benzenedisul fonimide as a Recyclable Bronsted Acid Catalyst

Background: One-Pot three component preparation of α-aminophosphonates in the presence of o-benzenedisulfonimide as efficient acidic organocatalyst has been described. The catalyst can be recovered for further reactions and reused without any loss of efficiency. Methods: A very simple protocol was followed in the reaction process. Initially, we attempted a three component coupling of benzaldehyde with aniline and trimethylphosphite using o-benzenedisulfonimide (5 mol%). The reaction proceeded smoothly at r.t under solvent free conditions and the desired product. Results: The reactions worked well with almost all the aldehydes, heteroaryl aldehydes and ketones; at the end of the reaction, the product could be separated by usual work up. Finally, the water tolerant catalyst may be recycled from water, because of its good solubility in water. Conclusion: The catalyst is a safe, nonvolatile, and noncorrosive Brønsted acid; it is readily recovered at the end of the reactions simply by evaporating the aqueous washings. The products are generally obtained in good yields and short time under simple and mild reaction conditions.