The catalytic performances of three organophosphonyl/arsonyl derivatives of POMs were evaluated for the epoxidation of limonene in acetonitrile, using aqueous H2O2 as the oxidant. All three W‐based POMs catalysts operated without any additional transition‐metal ions and displayed excellent conversion for limonene at temperatures varying from 4 to 50 °C. Furthermore, the use of B,α‐[NaHAsW9O33{P(O)R}2]3– (R = tBu, ‐CH2CH2CO2H) complexes led to the complete conversion of limonene to epoxylimonene at 4 °C. The selectivity of the reaction was modulated by varying the reaction solvent, and it was found that allylic reactions were favored in ethanol. The effect of the catalyst protonation was also investigated by DFT calculations, highlighting the role of protons in the epoxidation process.

Invited for the cover of this issue are Richard Villanneau, Sorbonne Université, Paris, Alain ShumàCheongàSing, Université de la Réunion, Saint‐Denis, France, and co‐workers. The cover image shows the oxidation of limonene to epoxylimonene against a background of orange trees typical of Réunion Island.

The Front Cover shows the oxidation of limonene to epoxylimonene with, in the background, orange trees typical of Réunion Island, where some of the studies reported in this manuscript have been carried out. Terpenes, especially limonene, are particularly present in citrus fruits, which constitute a part of the island's natural resources. The use of hybrid derivatives of polyoxometalates as effective catalysts from low temperatures allows their selective oxidation even within essential oils. More information can be found in the Full Paper by A. Shum Cheong Sing, R. Villanneau et al. For more on the story behind the cover research, see the Cover Profile.