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The first organocatalyzed trapping of CO₂ through CC and CO bond formation is reported. Alkynyl indoles together with catalytic amounts of an organic base and five equivalents of CO₂ resulted in the formation new heterocyclic structures. These tricyclic indole-containing products were successfully prepared under mild reaction conditions from aromatic, heteroaromatic, and aliphatic alkynyl indoles with complete regioselectivity. Further investigations suggest that CC bond formation is the initial intermolecular step, followed by lactone-forming CO bond formation.

Caught in a trap: The first trapping of CO₂ through organocatalyzed CC and CO bond formation is reported. By using alkynyl indoles, this method generates novel indole lactone derivatives by using as little as 5 mol % of the simple organic base 1,5,7-triazabicyclo-[4.4.0]dec-5-ene as an organocatalyst. The transformation shows excellent atom economy and a broad substrate scope, including aromatic, heteroaromatic, and aliphatic 2-alkynyl indoles.

Shrouded in mystery, the interface structure of ionic liquids is unclear despite their popularity for electrochemical applications. In their Communication on page 6062 ff., O. M. Magnussen et al. address the molecular arrangement and sub-second dynamics of these iconic compounds on gold electrodes by high-speed tunneling microscopy. With decreasing potential, distinct transitions in the structure and surface mobility of the innermost layer of 1-butyl-1-methylpyrrolidinium cations are found.

Ionic liquids (ILs) with a reversible hydrophobic–hydrophilic transition were developed, and they exhibited unique phase behavior with H₂O: monophase in the presence of CO₂, but biphase upon removal of CO₂ at room temperature and atmospheric pressure. Thus, coupling of reaction, separation, and recovery steps in sustainable chemical processes could be realized by a reversible liquid–liquid phase transition of such IL-H₂O mixtures. Spectroscopic investigations and DFT calculations showed that the mechanism behind hydrophobic–hydrophilic transition involved reversible reaction of CO₂ with anion of the ILs and formation of hydrophilic ammonium salts. These unique IL-H₂O systems were successfully utilized for facile one-step synthesis of Au porous films by bubbling CO₂ under ambient conditions. The Au porous films and the ILs were then separated simultaneously from aqueous solutions by bubbling N₂, and recovered ILs could be directly reused in the next process.

Three birds with one stone: ILs with strong hydrophobicity were developed. Their reversible hydrophobic–hydrophilic transition, switched by bubbling with and removal of CO₂ under ambient conditions, is due to the reversible reaction between CO₂ and anions to form hydrophilic ammonium salts. Homogeneous synthesis and heterogeneous separation of Au porous films as well as recovery of the ILs were coupled to achieve sustainable chemical processes.