Mannich Reaction of Sulfonylacetates

Significance

Ricci, Bernardi and co-workers report a phase-transfer-catalyzed enantioselective Mannich addition of arylsulfonylacetates to highly reactive N-carbamoyl imines generated in situ from α-amidosulfones. Reductive removal of the sulfonyl group of the Mannich adducts yields the corresponding N-Boc- or N-Cbz-protected β^³-amino-esters whereas a Julia-type olefination gives access to aza-Morita-Baylis-Hillman-type products. This transformation was carried out with different linear, α- or β-branched, and aromatic α-amido-sulfones in moderate to good yields with high enantioselectivities.