Co(III) Complexes with NS-Type Ligands as Structural/Functional Models for the Isocyanide Hydrolysis Reaction Catalyzed by Nitrile Hydratase.

It has been before reported that, in addition to hydration of nitriles, the Fe-type nitrile hydratase (NHase) also catalyzes the hydrolysis of tert-butylisocyanide ( tBuNC). In order to investigate the unique isocyanide hydrolysis by NHase, we prepared three related Co(III) model complexes, PPh[Co(L)] (1), PPh[Co(L-O)] (2), and PPh[Co(L-O)] (3), where L is bis( N-(2-mercapto-2-methylpropionyl)aminopropyl)sulfide. The suffixes L-O and L-O indicate ligands with a sulfenate and a sulfinate and with two sulfinates, respectively, instead of the two thiolates of L.