Synthesis of Unnatural Selenocystines and β-Aminodiselenides via Regioselective Ring-Opening of Sulfamidates Using a Sequential, One-Pot, Multistep Strategy

A variety of N-alkyl-β-aminodiselenides have been synthesized in high yield from sulfamidates under mild reaction conditions using potassium selenocyanate and benzyltriethylammonium tetrathiomolybdate ([BnNEt3]2MoS4) in a sequential, one-pot, multistep reaction. The tolerance of multifarious protecting groups under the reaction conditions is discussed. The methodology was successfully extended to the synthesis of selenocystine, 3,3′-dialkylselenocystine, and 3,3′-diphenylisoselenocystine and their direct incorporation into peptides.