In the colloidal synthesis of iron sulfides, a series of dialkyl disulfides, alkyl thiols, and dialkyl disulfides (allyl, benzyl, tert-butyl, and phenyl) were employed as sulfur sources. Their reactivity was found to tune the phase between pyrite (FeS2), greigite (Fe3S4), and pyrrhotite (Fe7S8). DFT was used to show that sulfur-rich phases were favored when the C–S bond strength was low in the organosulfurs, yet temperature dependent studies and other observations indicated the reasons for phase selectivity were more nuanced; the different precursors decomposed through different reaction mechanisms, some involving the oleylamine solvent. The formation of pyrite from diallyl disulfide was carefully studied as it was the only precursor to yield FeS2. Raman spectroscopy indicated that FeS2 forms directly without an FeS intermediate, unlike most synthetic procedures to pyrite. Diallyl disulfide releases persulfide (S–S)2– due to the lower C–S bond strength relative to the S–S bond strength, as well as facile decomposition in the presence of amines through SN2′ mechanisms at elevated temperatures.

Simple cationic bis(phosphine)iridium complexes are shown to be highly selective catalysts for ether cleavage with silanes. Benzylic ethers can be cleaved under mild conditions in the presence of reductively-labile functional groups.

Cationic bis(phosphine)iridium complexes are found to catalyze the cleavage of cyclohexyl methyl ethers by triethylsilane. Selectivity for C−O cleavage is determined by the relative rates of S N 2 demethylation versus S N 1 demethoxylation, with the axial or equatorial disposition of the silyloxonium ion intermediate acting as an important contributing factor. Modulation of the electron-donor power of the supporting phosphine ligands enables a switch in selectivity from demethylation of equatorial methyl ethers to 2°demethoxylation. Applications of these accessible catalysts to the selective demethoxylation of the 3α-methoxy group of cholic acid derivatives is demonstrated, including a switch in observed selectivity controlled by 7α-substitution. The resting state of the catalyst has been characterized for two phosphine derivatives, demonstrating that the observed switch in C−O cleavage selectivity likely results from electronic factors rather than from a major perturbation of the catalyst structure.

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The cleavage of alkyl ethers by hydrosilylation is a powerful synthetic tool for the generation of silyl ethers. Previous attempts to apply this transformation to carbohydrate derivatives have been constrained...