Iron Carbonyl Sulfides, Formaldehyde, and Amines Condense To Give the Proposed Azadithiolate Cofactor of the Fe-Only Hydrogenases

Citations Over TimeTop 10% of 2002 papers

Abstract

The azadithiolate (SCH2NHCH2S) cofactor proposed to occur in the Fe-only hydrogenases forms efficiently by the condensation of Fe2(SH)2(CO)6 (1), formaldehyde, and ammonia (as (NH4)2CO3). The resulting Fe2[(SCH2)2NH](CO)6 reacts with Et4NCN to give (Et4N)2[Fe2[(SCH2)2NH](CO)4(CN)2], for which crystallographic characterization confirmed an axial N-H and an elongated C-S bond of 1.858(3) A. Primary amines RNH2 (R = Ph, t-Bu) also participate in the condensation reaction, and Fe3S2(CO)9 can be employed in place of 1. Mechanistically, the Fe2[(SCH2)2NH] moiety is shown to arise via two pathways: (i) via the intermediacy of Fe2[(SCH2OH)2](CO)6, which was detected and shown to react with amines, and (ii) via the reaction of 1 with cyclic imines (CH2)3(NR)3 (R = Ph, Me). The reaction of 1 with (CH2)6N4 (hexamethylenetetramine) gives Fe2[(SCH2)2NH](CO)6. Trace amounts of Fe2[(SCH2)2N-t-Bu](CO)6 arise via the reaction of aqueous FeSO4, formaldehyde, NaSH, and t-BuNH2 under an atmosphere of CO.

Related Papers

• → Revisiting the condensation reaction of lignin in alkaline pulping with quantitativity part III: predominant formation of α-β-type over α-5-type condensation product in soda cooking treatments of apocynol and creosol(2022)12 cited
• → An aldimine condensation reaction based fluorescence enhancement probe for detection of gaseous formaldehyde(2020)31 cited
• → Preparation of [Fe]-Hydrogenase from Methanogenic Archaea(2011)41 cited
• → Condensation Reactions of o-Phthalaldehydic Acid. III-VI. III. On the Condensation Reaction of o-Phthalaldehydic Acid with Hydantoin, 3-Phenylhydantoin and 3-Methylhydantoin(1960)2 cited
• → Condensation Reaction of Formaldehyde with Phenols. XII. Simple Method of Direct Synthesis of Saligenine from Phenol and Formaldehyde.(1954)1 cited