In Situ Synthesis\nof Iron-Based Porphyrin Metal–Organic\nFrameworks for the Baeyer–Villiger Oxidation Using Air as an\nOxidant

Iron-based porphyrin metal–organic frameworks\n(PMOFs) are\na new type of material with good stability, catalytic activities,\nand reusability, which have broad application prospects. However,\nthe synthesis of iron-based PMOFs with different metalloporphyrin\nunits requires a considerable amount of reagents and time. Herein,\nan in situ synthesis method was developed to simplify the synthetic\nprocess of iron-based PMOFs. A series of highly stable iron-based\nPMOFs (M<sub>situ</sub>-PMOF-3(Fe) (M = Fe, Co, Ni, Cu, Pd)) were\nsynthesized in one pot without the preparation of metalloporphyrin\nligands in advance. This synthesis method is simpler and more efficient,\nsaving considerable time and material costs. The resultant M<sub>situ</sub>-PMOF-3(Fe) exhibits a high tolerance to aqueous solutions with pH\nranging from 0 to 11, as well as various organic solvents. The catalytic\nexperiments show that both Fe<sub>situ</sub>-PMOF-3(Fe) and Co<sub>situ</sub>-PMOF-3(Fe) can catalyze the Baeyer–Villiger oxidation\nof cyclohexanone using air as an oxidant at 35 °C. Moreover,\nwhen the mixtures of Fe<sub>situ</sub>-PMOF-3(Fe) and Co<sub>situ</sub>-PMOF-3(Fe) were employed as catalyst, they can exert a cooperative\ncatalysis effect, resulting in a significantly enhanced catalytic\nactivity compared to a single component. The mild reaction condition,\nhigh catalytic efficiency, and excellent selectivity endow this catalytic\nsystem with a good application prospect. This work not only provides\na new approach for the synthesis of iron-based PMOFs but also offers\nguidance for the Baeyer–Villiger oxidation reactions using\nair under mild conditions.