Efficient Synthesis of Substituted Cyclic α-Aminophosphonates

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