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Multisubstituted alkenes are accessible by a gold-catalyzed acyloxyalkynylation of ynamides with ethynylbenziodoxolones (EBXs) with perfect atom-economy. The EBX reagents transfer both the carboxylate as well as the alkynyl entity. Overall, this cascade comprises the in situ generation of an alkynyl gold(III) species, a stereoselective C(sp)-C(sp

The development of new methodologies enabling a facile access to valuable heterocyclic frameworks still is an important subject of research. In this context, we describe a dual catalytic cycle merging C−H alkynylation of phenols and oxy‐alkynylation of the newly introduced triple bond by using a unique redox property and the carbophilic π acidity of gold. Mechanistic studies support the participation of a bimetallic gold–silver species. The one‐pot protocol offers a direct, simple, and regio‐specific approach to 3‐alkynyl benzofurans from readily available phenols. A broad range of substrates, including heterocycles, is transferred with excellent functional group tolerance. Thus, this methodology can be used for the late‐stage incorporation of benzofurans., A mild and general synthesis of 3‐alkynylbenzofurans from readily available phenols by Au–Ag bimetallic catalysis has been developed. Importantly, this also advances our mechanistic understanding of the “silver effect” in gold redox chemistry.

A highly efficient mercury-free route, providing [C^N] cyclometalated symmetric dialkynyl gold(III) complexes with 2-(p-tolyl)pyridine (tpy) as bidentate ligands and using alkynyllithium reagents, ...

Efficient synthetic approaches of incorporation of nitrogen into polyaromatic hydrocarbons (PAHs) in different patterns as stabilising moiety for p-extended systems and modification tool for optoelectronic properties remains a challenge until today. In this work we developed a new versatile pathway to napthyridine-based PAHs as non-symmetric and regioisomeric pendant to pyrazine-based PAHs. A combination of a gold-catalysed synthesis of 2-aminoquinolines and the development of an in situ desulfonation and condensation of these precursors are the key steps of the protocol. The shape and type of attached functional groups of the PAHs can be designed in a late stage of the overall synthetic procedure by the chosen anthranile and backbone of the ynamide introduced in the gold-catalysed step. Single crystal X-ray diffraction and the investigation of electronic properties of the compounds show the influence of the attached substituents. All naphthyridine based PAHs show halochromic behaviour implying their use as highly sensitive proton sensor in non-protic solvents.

Push-pull diaryl alkynes are dimerized in the presence of a cationic gold catalyst. The polarized structure of the applied starting materials enables the generation of a highly reactive vinyl cation intermediate in an intermolecular reaction. Trapping of the vinyl cation by a nucleophilic attack of the electron-poor aryl unit then leads to the selective formation of highly substituted naphthalenes in a single step and in complete atom economy.

The molecular arrangement of polymeric organic semiconductors alter the macroscopic optoelectronic properties of the material. Most existing solution-based deposition methods are however, limited in both resolution as well as pattern design and often result in molecular disorder upon drying. Here, a method for aligning the amorphous polymer polyindenofluoren-8-triarylamine (PIF8-TAA) via inkjet printing is presented. By tuning the printing speed and including different amounts of the solid solvent crystallization agent 1,3,5-trichlorobenzene (TCB), fibrous structures with varying morphology can be fabricated. The resulting optical properties are analyzed using photoluminescence and Raman spectroscopy. The findings show an optical anisotropic behavior dependent on the fiber size and alignment. This is likely caused by the increased molecular arrangement within the structures. Methods enabling tailored structuring of the molecular arrangement in a material, provide the possibility to develop novel applications, as well as to optimize existing devices with improved properties such as, charge carrier transport and emission efficiency.