Enantio- and diastereoselective hetero-Diels–Alder reactions between 2-aza-3-silyloxy-1,3-butadienes and aldehydes catalyzed by chiral dirhodium(ii) carboxamidates

Abstract

The first catalytic asymmetric hetero-Diels-Alder reaction between 2-aza-3-silyloxy-1,3-butadienes and aldehydes is described. With dirhodium(II) tetrakis[N-benzene-fused-phthaloyl-(S)-piperidinonate], Rh(2)(S-BPTPI)(4), the cycloaddition reaction proceeded exclusively in an endo mode to give all-cis-substituted 1,3-oxazinan-4-ones in high yields with up to 98% ee.