Dimeric Gold Bis(carbene) Complexes by Transmetalation in Water

Due to its cost, environmental benefits, and safety advantages, water has become more and more important as a solvent for catalytic reactions and constitutes the best environment for biomedical applications. Therefore, water-soluble and water-stable metal complexes containing strong σ-donor ligands such as N-heterocyclic carbenes (NHCs) are of great interest in modern coordination chemistry. In this paper we present the successful preparation of two new dinuclear gold­(I)–bis­(NHC) complexes in water, by applying the Ag–NHC transfer route. This green synthetic strategy is valuable for gold­(I) compounds involving N-functionalized neutral and dianionic bis­(NHC) ligands. These two water-soluble compounds were analyzed by spectroscopic methods and by X-ray diffraction. Furthermore, ab initio and DFT calculations on the corresponding dinuclear gold complexes illustrate the important influence of the electrostatic environment of the dinuclear entity on the aurophilic interactions and help to understand the molecular arrangement presented in this paper

Dimeric Gold Bis(carbene) Complexes by Transmetalation in Water

Due to its cost, environmental benefits, and safety advantages, water has become more and more important as a solvent for catalytic reactions and constitutes the best environment for biomedical applications. Therefore, water-soluble and water-stable metal complexes containing strong σ-donor ligands such as N-heterocyclic carbenes (NHCs) are of great interest in modern coordination chemistry. In this paper we present the successful preparation of two new dinuclear gold­(I)–bis­(NHC) complexes in water, by applying the Ag–NHC transfer route. This green synthetic strategy is valuable for gold­(I) compounds involving N-functionalized neutral and dianionic bis­(NHC) ligands. These two water-soluble compounds were analyzed by spectroscopic methods and by X-ray diffraction. Furthermore, ab initio and DFT calculations on the corresponding dinuclear gold complexes illustrate the important influence of the electrostatic environment of the dinuclear entity on the aurophilic interactions and help to understand the molecular arrangement presented in this paper

Superbases in Confined Space: Control of the Basicity and Reactivity of the Proton Transfer

Endohedral functionalization of the molecular cavity of host molecules is in high demand in many areas of supramolecular chemistry. When highly reactive species are incarcerated in the confined space of a molecular cavity, deep changes of their chemical properties are expected. Here, we show that the superbasic properties of proazaphosphatranes can be improved in the confined space of the molecular cavity of hemicryptophane hosts. A general and modular procedure is described to prepare supramolecular superbases with various cavity sizes. The rate of proton transfer is strongly dependent on the shape and size of the inner cavity of the designed superbasic structure. Kinetic and thermodynamic data are strongly correlated to the space available around the basic center as revealed by the X-ray molecular structures analyses

Spirobis(pentagerma[1.1.1]propellane): A Stable Tetraradicaloid

In this contribution, we report a spirobis­(pentagerma[1.1.1]­propellane) derivative as a novel type of molecular architecture in cluster chemistry that features two spiro-fused [1.1.1]­propellane units and represents a stable tetraradicaloid species. The crucial issue of the nature of the interaction between the germanium bridgeheads was probed computationally, revealing weak bonding interactions between the formally unpaired electrons

Spirobis(pentagerma[1.1.1]propellane): A Stable Tetraradicaloid

In this contribution, we report a spirobis­(pentagerma[1.1.1]­propellane) derivative as a novel type of molecular architecture in cluster chemistry that features two spiro-fused [1.1.1]­propellane units and represents a stable tetraradicaloid species. The crucial issue of the nature of the interaction between the germanium bridgeheads was probed computationally, revealing weak bonding interactions between the formally unpaired electrons

Superbases in Confined Space: Control of the Basicity and Reactivity of the Proton Transfer

Endohedral functionalization of the molecular cavity of host molecules is in high demand in many areas of supramolecular chemistry. When highly reactive species are incarcerated in the confined space of a molecular cavity, deep changes of their chemical properties are expected. Here, we show that the superbasic properties of proazaphosphatranes can be improved in the confined space of the molecular cavity of hemicryptophane hosts. A general and modular procedure is described to prepare supramolecular superbases with various cavity sizes. The rate of proton transfer is strongly dependent on the shape and size of the inner cavity of the designed superbasic structure. Kinetic and thermodynamic data are strongly correlated to the space available around the basic center as revealed by the X-ray molecular structures analyses

Spirobis(pentagerma[1.1.1]propellane): A Stable Tetraradicaloid

In this contribution, we report a spirobis­(pentagerma[1.1.1]­propellane) derivative as a novel type of molecular architecture in cluster chemistry that features two spiro-fused [1.1.1]­propellane units and represents a stable tetraradicaloid species. The crucial issue of the nature of the interaction between the germanium bridgeheads was probed computationally, revealing weak bonding interactions between the formally unpaired electrons

Superbases in Confined Space: Control of the Basicity and Reactivity of the Proton Transfer

Endohedral functionalization of the molecular cavity of host molecules is in high demand in many areas of supramolecular chemistry. When highly reactive species are incarcerated in the confined space of a molecular cavity, deep changes of their chemical properties are expected. Here, we show that the superbasic properties of proazaphosphatranes can be improved in the confined space of the molecular cavity of hemicryptophane hosts. A general and modular procedure is described to prepare supramolecular superbases with various cavity sizes. The rate of proton transfer is strongly dependent on the shape and size of the inner cavity of the designed superbasic structure. Kinetic and thermodynamic data are strongly correlated to the space available around the basic center as revealed by the X-ray molecular structures analyses

Remote Stereocontrol in the Synthesis of Acyclic 1,4-Diols and 1,4‑Aminoalcohols from 2‑Sulfinyl Dienes

The highly diastereoselective conjugate addition of alcohols and amines (RXH) to enantiopure 2-sulfinyl dienes renders transient allylic sulfoxides which undergo sulfoxide–sulfenate rearrangement and sulfenate cleavage providing 2-ene-1,4-diols and 2-ene-1,4-aminoalcohols with up to 99:1 dr. The method allows for the generation of two stereocenters in a single synthetic operation with remote chirality transfer of one center into the other

Remote Stereocontrol in the Synthesis of Acyclic 1,4-Diols and 1,4‑Aminoalcohols from 2‑Sulfinyl Dienes

The highly diastereoselective conjugate addition of alcohols and amines (RXH) to enantiopure 2-sulfinyl dienes renders transient allylic sulfoxides which undergo sulfoxide–sulfenate rearrangement and sulfenate cleavage providing 2-ene-1,4-diols and 2-ene-1,4-aminoalcohols with up to 99:1 dr. The method allows for the generation of two stereocenters in a single synthetic operation with remote chirality transfer of one center into the other