Thiolate‐protected gold nanoclusters (AuNCs) have attracted significant attention as nano‐catalysts, revealing a superatomic core and gold‐thiolate staples as distinct structural units. Here, we demonstrate the unprecedented dual catalytic activity of thiolate‐protected [Au₂₅(SR)₁₈]⁻ nanoclusters, involving both photosensitized ¹O₂ generation by the Au₁₃ superatomic core and catalytic carbon‐carbon bond formation facilitated by Au₂(SR)₃ staples. This synergistic combination of two different catalytic units enables efficient cross‐dehydrogenative coupling of terminal alkynes and tertiary aliphatic amines to afford propargylamines in high yields of up to 93 %. Mixed‐ligand AuNCs bearing both thiolate and alkynyl ligands revealed the intermediacy of the alkynyl‐exchanged AuNCs toward both photosensitization and C−C bond‐forming catalytic cycles. Density functional theory calculations also supported the intermediacy of the alkynyl‐exchanged AuNCs. Thus, the use of ligand‐protected metal nanoclusters has enabled the development of an exceptional multifunctional catalyst, wherein distinct nanocluster components facilitate cooperative photo‐ and chemo‐catalysis.

Iron oxide nanoparticles (NPs) are nontoxic and abundant materials which have long been investigated as reusable catalysts in oxidation reactions, but their use so far has been hampered by a low selectivity. Here, unsupported iron oxide NPs have been found to successfully catalyze the microwave-assisted oxidation of primary and secondary alcohols to their respective aldehydes and ketones with a high selectivity when N-methylmorpholine N-oxide was used as the terminal oxidant. The crystalline phase and size of the iron-based catalyst have a drastic effect on its activity, with small magnetite (Fe3O4) NPs being the optimal catalyst for this reaction. The nanocatalyst could be easily recovered by magnetoseparation and successfully recycled four times without any need for special pretreatment or reactivation step and with a minimal loss of activity. The subsequent loss of activity was attributed to the transition from magnetite (Fe3O4) to maghemite (gamma-Fe2O3), as confirmed by X-ray diffraction, Fourier transform infrared, and X-ray absorption near-edge spectroscopy. The nanocatalyst could then be reactivated by the high-temperature microwave treatment and used again for the microwave-assisted oxidation reaction.

The first iron-catalysed cross coupling of propargyl electrophiles with lithium alkenylborates has been developed. Various propargyl electrophiles can be cross-coupled with lithium (E)- or (Z)-alkenylborates in a stereospecific manner to afford the corresponding 1,4-enynes in good to excellent yields. The reaction features high S_N2-type regioselectivity and functional group compatibility.