No abstract

As [FeFe]-hydrogenase models, the first thiodithiolate (TDT) ligand-containing μ-hydride complexes [(μ-TDT)Fe2(CO)4(PMe3)2(μ-H)](+)Y(-) (2-7, Y = Cl, ClO4, PF6, BF4, CF3CO2, CF3SO3) have been prepared by protonation reactions of (μ-TDT)Fe2(CO)4(PMe3)2 (1) with the corresponding HY acids. While the protonation reactions are monitored by in situ(1)H and (31)P{(1)H} NMR spectroscopy to show the isomer type and stability of 2-7, the structures of the isolated 2-7 are characterized by elemental analysis, spectroscopy and for some of them by X-ray crystallography. Although the H/D exchange of μ-hydride complex 7 (Y = CF3SO3) with D2 or D2O has been proved not to occur under the studied conditions, the H/D exchange of 7 with DCl gives the μ-deuterium complex [(μ-TDT)Fe2(CO)4(PMe3)2(μ-D)](+)[CF3SO3](-) (8) in a nearly quantitative yield. To our knowledge, 8 is the first crystallographically characterized μ-deuterium-containing butterfly [2Fe2S] complex produced by H/D exchange reaction.

Silica-supported phosphorus chloride has been proved to be an efficient and recyclable catalyst for Beckmann rearrangement of a variety of ketoximes and dehydration of various aldoximes in anhydrous THF under microwave irradiation. This protocol has advantages of high conversion, high selectivity, short reaction time, no environmental pollution, and simple work-up procedure.

Interestingly, the intermediate salts A·[Et 3 NH] (A = (μ-RS)(μ-CO)Fe 2 (CO) 6 ; R = i-Pr, sec-Bu, cy-C 6 H 11 , pMeC 6 H 4 ) prepared from Fe 3 (CO) 12 , RSH, and Et 3 N were found to react in situ with iodobenzene or its substituted derivatives in the presence of the catalyst precursor Pd(PPh 3 ) 4 to give the benzoyl type μ-acyl complexes (μ-RS)(μ-ArCO)-Fe 2 (CO) 6 (Ar = phenyl or substituted phenyl), whereas the in situ reactions of A·[Et 3 NH] with iodo-substituted aromatic heterocycles under the same conditions afforded the corresponding heterocyclic type μ-acyl complexes (μ-RS)(μ-ArCO)-Fe 2 (CO) 6 (Ar = heterocyclic or benzoheterocyclic group). Particularly worth noting is that such Pd-catalyzed C−C bond cross-coupling reactions are the first examples of catalytic reactions regarding A·[Et 3 NH] salts reported so far. In addition, all the prepared new μ-acyl complexes and the three new intermediate salts A·[Et 3 NH] (R = i-Pr, sec-Bu, cy-C 6 H 11 ) were isolated and structurally characterized, while a possible pathway for such type Pd-catalyzed reactions regarding A·[Et 3 NH] salts is suggested.