Asymmetric Synthesis of α-Chloro-β-amino-N-sulfinyl Imidates as Chiral Building Blocks

New chiral alpha-chloro-beta-amino-N-sulfinyl imidates were synthesized in high yield and excellent diastereomeric excess via highly anti-selective Mannich-type reactions of (R-S)-methyl N-tert-butanesulfinyl-2-chloroethanimidate with aromatic aldimines. The alpha-chloro-beta-amino-N-sulfinylimidates proved to be excellent building blocks for the asymmetric synthesis of beta-amino-alpha-chloro amides and esters, aziridine-2-carboxylic amides and esters, trans-2-aryl-3-chloroazetidines, and methyl 4-phenyloxazolidin-2-one-5-carboxylate. The obtained absolute anti-diastereoselectivity is the opposite of the stereochemical outcome observed for alpha-methyl-substituted imidates.