Catalytic C–H and C–S Bond Activation of Thiophenes

Abstract

A new Pd-catalyzed reaction of thiophenes with alkynes via C-H and C-S bond activation has been developed. This provides a new approach to prepare sulfur-containing compounds. An interesting salt effect was observed, and the reaction's efficiency and selectivity depend not only on the type but also on the amount of the salt used.

Reversible C60 Ejection from a Metallocage through the Redox‐Dependent Binding of a Competitive Guest

“…Very few examples of stimuli‐responsive fullerene release concomitant with the recovery of the host platform are described in the literature. The strategies reported so far are either based on the modification of the host molecule through a structural rearrangement (acid/based treatment, addition of a metal, ion‐regulated allosteric changes), on its reversible disassembly (photoreduction of the metal ions), or on its precipitation (after prolonged heating) . Therefore, the development of novel reversible systems able to uptake and release fullerenes on demand is highly required, especially those focusing on the guest structure rather than the host.…”

Incarceration of Higher‐Order Fullerenes within Cyclotriveratrylene‐Based Hemicarcerands Allows Selective Isolation of C76, C78, and C84 from a Commercial Fullerene Mixture

“…Previously, we used molecular cage 1 (Figure d) to isolate C 70 in high purity (≥99.0 %) directly from a fullerene extract, thus taking advantage of room‐temperature‐isolable hemicarceplexes (formed from the sequestration of complementary guests within hemicarcerands) and releasing the guests at elevated temperatures. Because the higher‐order fullerenes are not much bigger than C 70 , their selective complexation of these compounds would require host molecules with only slightly larger cavities and openings.…”

Metallosupramolecular receptors for fullerene binding and release

“…Metalloporphyrins contain a large p-conjugated system, thus they tend to act as p-donor moieties. 16 (c) A representation of the solid state structure of the [Sc 3 N@C 80 ]C2 hostguest adduct (hydrogen atoms are omitted for clarity). 19 Nevertheless, this interaction is weak in solution and is difficult to visualize spectroscopically.…”

“…Consequently, harsh methodologies such as high temperatures or acidic conditions can be applied in order to release the entrapped fullerene without causing host decomposition. 16 Taking advantage of the higher affinity towards C 70 , the authors designed an experimental protocol to isolate C 70 from the fullerene extract. 1), Chiu and co-workers were able to selectively encapsulate C 70 fullerene from a mixture of fullerenes (Fig.…”