Synthesis of new β- and γ-aminopyrrolidinephosphonates via 1,3-dipolar cycloaddition of substituted vinylphosphonates

Synthesis of α- and β-(aminomethyl)vinylphosphonates was achieved from vinyl bromide via a cross-coupling reaction with triethyl phosphite and by cross-metathesis of allyl bromide and vinylphosphonate, respectively. The 1,3-dipolar cycloaddition of these vinylphosphonates with a dipole in the presence of trifluoroacetic acid afforded selectively the β-aminopyrrolidinephosphonates. Syntheses of cis- and trans-γ-aminopyrrolidinephosphonates are also described.