Self-assembled multilayer iron(0) nanoparticles (NPs, 6–10 nm), namely, sulfur-modified Au-supported Fe(0) [SAFe(0)], were developed for ligand-free one-pot carbon–carbon/carbon–nitrogen bond-forming reactions. SAFe(0) was successfully prepared using a well-established metal–nanoparticle catalyst preparative protocol by simultaneous in situ metal NP and nanospace organization (PSSO) with 1,4-bis­(trimethylsilyl)-1,4-dihydropyrazine (Si-DHP) as a strong reducing agent. SAFe(0) was easy to handle in air and could be recycled with a low iron-leaching rate in reaction cycles.

Reactions of ruthenium carbene catalysts, including their metathesis, nonmetathesis, and decomposition reactions, have been extensively studied because of their importance in organic synthesis. Here, we developed a novel cross-coupling reaction between 1,4-naphthoquinone and NHC ligands on ruthenium benzylidene complexes via intramolecular C­(sp3)–H bond activation. Also, we discovered a novel tricyclic blue pigment, 2-(1-mesityl-5,7-dimethyl-2,3-dihydro-1H-imidazo­[1,2-a]­indol-9-yl)­naphthalene-1,4-dione, as a product of the reaction.