Endohedral Mixed Aggregates: Sodium Alkoxide Cages with Organic or Inorganic Central Anions and Variable Hull

Rapid Access to Isoprenoid Quinones through X@RONa-Catalyzed Redox Chain Reaction

Dodecameric sodium alkoxide clusters encaging a halide anion (X@RONa) were shown to be C-C bond formation catalysts in the redox chain reaction of quinones. With up to 30 mol % tert-decanol as the catalyst and stoichiometric base NaH, a great number of chemically sensitive isoprenoid quinones, including health-relevant Coenzyme Q and Vitamin K family compounds, were easily made in one step from their parent quinones and polyprenyl halide. The X@RONa clusters and possible cluster-derived intermediates were studied by characterization techniques, control experiments, and theory. The X@RONa clusters likely facilitated the C-alkylation step by preventing O-alkylation, promoting dissociation of halide from the alkyl chain, and transporting hydride into the nonpolar solvent.

Scalable Transition-Metal-Free Synthesis of Aryl Amines from Aryl Chlorides through X@RONa-Catalyzed Benzyne Formation

Aryl amines are highly useful organic chemicals, but large-scale, transition-metal-free syntheses of aryl amines are surprisingly underdeveloped. A mild and scalable (up to 500 mmol) aryl amine synthesis from benzyne chemistry was invented using easily accessible aryl chlorides as precursors, NaH as a stoichiometric base, and a new type of sodium alkoxide cluster, X@RONa, as a catalyst. The cluster catalyst X@RONa featured an externally hydrophobic dodecameric sodium alkoxide shell housing an encapsulated center anion. The cluster made from methoxy-tert-butanol was found to be the most effective. The intramolecular version of this reaction allowed the synthesis of indolines and indoles. Experimental and computational mechanistic studies revealed that the rate-determining step was likely the transport of solid NaH into the X@RONa cluster in the organic phase.

Size- and shape-adaptable mixed-alkoxide-aggregates: encapsulation of tetrafluoroborate and butadiynediide

Treatment of silyl compounds with excess sodium tert-butoxide results in encapsulation of the released anion. While the BF4− anion just fits in a spherical sodium alkoxide hull, the butadiyenediide dianion pierces its hull resulting in dimerisation.

Cage-like manganesesilsesquioxanes: features of their synthesis, unique structure, and catalytic activity in oxidative amidations

A family of Mn-based cage-like silsesquioxanes (and complexes with 1,10-phenanthroline) exhibits unique types of molecular architectures and catalytic activity in oxidative amidation reactions.

Endohedral Mixed Aggregates: Sodium Alkoxide Cages with Organic or Inorganic Central Anions and Variable Hull

Alkali metal alkoxides are widely used in chemistry due to their Brønsted basic and nucleophilic properties. Potassium alkoxides assist alkyllithium in the metalation of hydrocarbons in Lochmann‐Schlosser‐bases. Both compounds form mixed aggregates, which enhance the thermal stability, solubility, and the basic reactivity of these mixtures. A very unusual spherical mixed alkoxy aggregate was discovered by Grützmacher et al., where a central dihydrogen phosphide anion is surrounded by a highly dynamic shell of thirteen sodium atoms and a hull of twelve tert‐butoxide groups. This structural motif can be reproduced by a reaction of trimethylsilyl compounds of methane, halogens, or pseudo‐halogens with excess sodium tert‐butoxide. A nucleophilic substitution releases the corresponding anion, which is then encapsulated by the sodium alkoxide units. The compounds are soluble in hydrocarbon solvents, enabling studies of solutions by high‐resolution NMR spectroscopy and IR/Raman studies of the crystalline materials.