Asymmetric synthesis of β- and γ-amidophosphonates by Diels–Alder reaction using chiral aminodiene: theoretical and experimental study of the facial selectivity of chiral N-dienyl lactam

Abstract

Asymmetric [4 + 2] cycloaddition of optically pure 1-aminodiene 1 onto substituted phosphonodienophiles 2 and 4 provided respectively chiral β- and γ-amidophosphonocyclohexenes with good selectivities. The absolute stereochemistry of the major diastereoisomer was experimentally proved by NMR experiments and the facial selectivity of diene 1 is discussed on the basis of ab initio calculations.