Herein, manganese oxides by simply pyrolyzing commercial MnCO3 are found to be active and stable for aerobic oxidative dehydrogenation of N‐heterocycles in the absence of any additives. The oxides are fully characterized by XRD, BET, XPS, and SEM. The analysis results suggest that high surface area, the involvement of Mn3+ and Mn4+ species, and labile lattice oxygen are key factors for the reactions. Moreover, kinetic analysis demonstrates that the apparent activation for oxidative dehydrogenation of 1,2,3,4‐tetrahydroquinoline is 37.7 kJ mol−1, and radical anions may involve in the reaction.

In this article, hydroxyapatites (HAPs) with different Ca/P ratios have been synthesized as the supports to prepare the MnO x / HAP catalysts for the aerobic oxidation of alcohols. The catalytic activity is strongly influenced by the Ca/P ratio and the calcination temperature as they can affect the acid and basic properties and oxidation state of MnO x of the catalysts. The optimized catalyst MnO x /HAP-10 can catalyze various primary alcohols to the corresponding aldehydes selectively with excellent conversion (up to 100 %), and can be easily recovered and reused at least four times without any appreciable loss of activity.

In the zwitterionic title compound, C18H22N2O4S, the dihedral angle between the aromatic rings is 16.39 (11)° and an intra­molecular N—H⋯O hydrogen bond occurs. In the crystal, mol­ecules are linked by O—H⋯O hydrogen bonds, forming chains propagating in [01].

In the title compound, [Mn(C8H8N3O3S2)2(H2O)4], the MnII atom (site symmetry ) adopts a slightly distorted octa­hedral MnO6 geometry. The mol­ecular conformation is supported by N—H⋯N and O—H⋯O hydrogen bonds. In the crystal, mol­ecules inter­act by O—H⋯O, O—H⋯S, N—H⋯O and N—H⋯S hydrogen bonds, thereby forming (011) sheets.

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