A novel
and highly enantioselective Ru-catalyzed hydrogenation of
N-sulfonylated-
-dehydroamino acids has been discovered
and demonstratedin the synthesis of an anthrax lethal factor inhibitor (LFI). Herein, this methodology is used to prepare
N-sulfonylated amino acids in up to 98%ee. This unprecedented hydrogenation uses a chiral Ru catalyst rather than Rh as typical for acylated dehydroamino acids
and esters,
andthis work reports the first asymmetric hydrogenation of a tetrasubstituted dehydroamino acid derivative using a Ru catalyst.