Palladium-Catalyzed Reactions of [Et3NH]+ Salts of [(μ-RS)(μ-CO)Fe2(CO)6]− Anions with Iodo-Aromatic Compounds To Give the Corresponding Butterfly μ-Acyl Fe/S Cluster Complexes
摘要:
Interestingly, the intermediate salts A [Et3NH] (A = (mu-RS)(mu-CO)Fe-2(CO)(6); R = i-Pr, sec-Bu, cy-C6H11, p-MeC6H4) prepared from Fe-3(CO)(12), RSH, and Et3N were found to react in situ with iodobenzene or its substituted derivatives in the presence of the catalyst precursor Pd(PPh3)(4) to give the benzoyl type mu-acyl complexes (mu-RS)(mu-ArCO)Fe-2(CO)(6) (Ar = phenyl or substituted phenyl), whereas the in situ reactions of A [Et3NH] with iodo-substituted aromatic heterocycles under the same conditions afforded the corresponding heterocyclic type mu-acyl complexes (mu-RS)(mu-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 [Et3NH] salts reported so far. In addition, all the prepared new mu-acyl complexes and the three new intermediate salts A [Et3NH] (R = i-Pr, sec-Bu, cy-C6H11) were isolated and structurally characterized, while a possible pathway for such type Pd-catalyzed reactions regarding A [Et3NH] salts is suggested.
A novel and efficient transitionmetal-free C–H bond halogenation of indole derivatives has been developed. 3-Halogenated (3-Br, 3-I) indoles are highly regioselectively produced by this protocol. Simple and readily available halide salts (TBAB, KI) are employed as the halogen source. The transitionmetal-free and the mild conditions make this protocol very easy to handle and practical.
An economical and scalable electrochemical protocol for regioselective 3C–H halogenation of indole derivatives is reported. This strategy provides access to a host of 3‐iodo‐, 3‐bromo‐, 3‐chloro‐, and 3‐thiocyanoindole derivatives under mild conditions using inexpensive (pseudo)halide salts as the sole reagent. No supplementary electrolyte salt is necessary.
Palladium-Catalyzed Reactions of [Et<sub>3</sub>NH]<sup>+</sup> Salts of [(μ-RS)(μ-CO)Fe<sub>2</sub>(CO)<sub>6</sub>]<sup>−</sup> Anions with Iodo-Aromatic Compounds To Give the Corresponding Butterfly μ-Acyl Fe/S Cluster Complexes
Interestingly, the intermediate salts A [Et3NH] (A = (mu-RS)(mu-CO)Fe-2(CO)(6); R = i-Pr, sec-Bu, cy-C6H11, p-MeC6H4) prepared from Fe-3(CO)(12), RSH, and Et3N were found to react in situ with iodobenzene or its substituted derivatives in the presence of the catalyst precursor Pd(PPh3)(4) to give the benzoyl type mu-acyl complexes (mu-RS)(mu-ArCO)Fe-2(CO)(6) (Ar = phenyl or substituted phenyl), whereas the in situ reactions of A [Et3NH] with iodo-substituted aromatic heterocycles under the same conditions afforded the corresponding heterocyclic type mu-acyl complexes (mu-RS)(mu-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 [Et3NH] salts reported so far. In addition, all the prepared new mu-acyl complexes and the three new intermediate salts A [Et3NH] (R = i-Pr, sec-Bu, cy-C6H11) were isolated and structurally characterized, while a possible pathway for such type Pd-catalyzed reactions regarding A [Et3NH] salts is suggested.