Fine-tuned aminal cleavage:: A concise route to differentially protected enantiopure syn-α,β-diamino esters

A survey of routes for aminal cleavage of N-sulfinylimidazolidines has been carried out, and selective conditions to cleave the aminal moiety while preserving the sulfinamide group unaltered have been found. Thus, the treatment of enantiopure N-sulfinylimidazolidines with aqueous H3PO4 in THF affords enantiopure N-sulfinyldiamino esters in excellent yields, while the presence of MeOH as cosolvent allows for the simultaneous removal of the sulfinamide group and aminal cleavage. The behavior of these substrates in a variety of chemical transformations has been explored.