Efficient Synthesis of Substituted Cyclic α-Aminophosphonates

The addition of diethyl phosphite to cyclic imines bearing alkyl, aryl, or heteroaryl substituents at the α-position in diethyl ether at room temperature presents an efficient route to substituted cyclic α-aminophosphonates. The application of boron trifluoride-diethyl ether complex as a catalyst significantly accelerates the reaction.