A palladium catalyzed C−H functionalization and consecutive β‐fluoride elimination reaction between indole heterocycles and fluorinated diazoalkanes is reported. This approach provides for the first time a facile method for the rapid synthesis of gem‐difluoro olefins using fluorinated diazoalkanes under mild reaction conditions. Cyclopropanation products were obtained when N‐arylated rather than N‐alkylated indoles were applied in this reaction. Mechanistic studies reveal the importance of the β‐fluoride elimination step in this transformation. This method presents a new concept for the simple and direct transfer of a 1‐aryl‐(2,2‐difluorovinyl) group to access gem‐difluoro olefins.

Synthosomes are polymer vesicles with transmembrane proteins incorporated into block copolymer membranes. They have been used for selective transport in or out of the vesicles as well as catalysis inside the compartments. However, both the insertion process of the membrane protein, forming nanopores, and the spreading of the vesicles on planar substrates to form solid-supported biomimetic membranes have been rarely studied yet. Herein, we address these two points and, first, shed light on the realtime monitoring of protein insertion via isothermal titration calorimetry. Second, the spreading process on different solid supports, namely, SiO 2 , glass, and gold, via different techniques like spin-and dip-coating as well as a completely new approach of potential-assisted spreading on gold surfaces was studied. While inhomogeneous layers occur via traditional methods, our proposed potential-assisted strategy to induce adsorption of positively charged vesicles by applying negative potential on the electrode leads to remarkable vesicle spreading and their further fusion to form more homogeneous planar copolymer films on gold. The polymer vesicles in our study are formed from amphiphilic copolymers poly(2-methyl oxazoline)block-poly(dimethylsiloxane)-block-poly(2-methyl oxazoline) (PMOXA-b-PDMS-b-PMOXA). Engineered variants of the transmembrane protein ferric hydroxamate uptake protein component A (FhuA), one of the largest β-barrel channel proteins, are used as model nanopores. The incorporation of FhuA Δ1-160 is shown to facilitate the vesicle spreading process further. Moreover, high accessibility of cysteine inside the channel was proven by linkage of a fluorescent dye inside the engineered variant FhuA ΔCVF tev and hence preserved functionality of the channels after spreading. The porosity and functionality of the spread synthosomes on the gold plates have been examined by studying the passive ion transport response in the presence of Li + and ClO 4 − ions and electrochemical impedance spectroscopy analysis. Our approach to form solid-supported biomimetic membranes via the potential-assisted strategy could be important for the development of new (bio-) sensors and membranes.

In diesem Artikel berichten wir über die palladiumkatalysierte Reaktion von Indolen mit fluorierten Diazoalkanen. Dieser Ansatz bietet nun erstmalig eine einfache Methode für die effiziente Synthese von gem‐Difluorolefinen unter milden Reaktionsbedingungen mit fluorierten Diazoalkane. Diese reagieren mit N‐alkylierten Indolen in einer C‐H‐Funktionalisierung gefolgt von einer β‐Fluorideliminierungsreaktion. Die entsprechenden Cyclopropanierungsprodukte werden erhalten, wenn in dieser Reaktion N‐arylierte Indole eingesetzt werden. In mechanistischen Studien können wir zeigen, dass eine β‐Fluorideliminierung einen zentralen Reaktionsschritt darstellt. Diese Methode ist damit ein neuartiges Konzept, das den einfachen und direkten Transfer einer 1‐Aryl‐(2,2‐difluorvinyl)‐Gruppe für die Synthese von gem‐Difluorolefinen ermöglicht.