CO2 cycloaddition to epoxides promoted by bis-thioether-phenolate Fe(II) and Fe(III) complexes

Highly Stereo-Controlled Synthesis of Fatty Acid-Derived Cyclic Carbonates by Using Iron(II) Complex and Nucleophilic Halide

“…We have reported a simple method to prepare a series of unsymmetrical iron­(II) bispincer-type complexes (Scheme ) via selective coupling of 2,6-dibromopyridine with amines to unsymmetrical pyridine-bridged pincer-type imidazolium salts, followed by coordination between the unsymmetrical ligands and iron­(II) salts . The majority of iron-based catalysts for cycloaddition produced in the past few years were accomplished using the Fe­(III), with only a few examples of iron-based catalysts in the Fe­(II) that were developed by Rieger et al, Capacchione et al, Abu-Surrah et al, van Leeuwen et al, and our group . Moreover, the catalytic efficiency of iron­(II) catalysts has been successfully investigated in the coupling of epoxides with CO 2 by our group. , …”

Metal Complexes Bearing Sulfur-Containing Ligands as Catalysts in the Reaction of CO2 with Epoxides

“…These findings were rationalized by DFT calculations showing that the rate-limiting step was the ring-opening of the epoxide that took place in the presence of two iron centers: one acted as the Lewis acid and the other one, as metallate, furnished the nucleophile (Figure 16). Lately, we also developed a new family of tridentate bisthioether phenolate ligands that supported both Fe(II) and Fe(III) centers [71]. It is worth noting that the both Fe(II) and Fe(III) The ferrate species 21 was also isolated and characterized both starting from the chloroderivative 20 and the bromo-derivative 22 by reaction with two and one equivalent of TBAB, respectively ( Figure 17 Lately, we also developed a new family of tridentate bisthioether phenolate ligands that supported both Fe(II) and Fe(III) centers [71].…”

“…Lately, we also developed a new family of tridentate bisthioether phenolate ligands that supported both Fe(II) and Fe(III) centers [71]. It is worth noting that the both Fe(II) and Fe(III) The ferrate species 21 was also isolated and characterized both starting from the chloroderivative 20 and the bromo-derivative 22 by reaction with two and one equivalent of TBAB, respectively ( Figure 17 Lately, we also developed a new family of tridentate bisthioether phenolate ligands that supported both Fe(II) and Fe(III) centers [71]. It is worth noting that the both Fe(II) and Fe(III) Figure 17.…”

“…Lately, we also developed a new family of tridentate bisthioether phenolate ligands that supported both Fe(II) and Fe(III) centers [71]. It is worth noting that the both Fe(II) and Fe(III) complexes existed in solution as mononuclear or dinuclear species depending on the steric bulk of the ligand (Figure 18).…”

Homogeneous Iron Catalysts in the Reaction of Epoxides with Carbon Dioxide

“…Later, the same research group reported on a system based on Fe(II) and Fe(III) complexes supported by new bis‐thioether phenolate ligands (Figure ), with the intention to clarify the effect of the oxidation state on the catalytic behaviour . Different from systems 22 and 23 (Figure and Figure ), the Fe(II) complexes 24a – c and the Fe(III) complexes 25a – c were found to be dinuclear or mononuclear depending on the ligand's bulkiness.…”