It is shown that corannulene-based strained psurfaces can be obtained through the use of mechanochemical Suzuki and Scholl reactions.B esides being solvent-free,t he mechanochemical synthesis is high-yielding,fast, and scalable. Therefore,gram-scale preparation can be carried out in afacile and sustainable manner.The synthesized nanographene structure carries positive (bowl-like) and negative (saddle-like) Gaussian curvatures and adopts an overall quasi-monkey saddle-type of geometry.Interms of properties,the non-planar surface exhibits ah igh electron affinity that was measured by cyclic voltammetry,w ith electrolysis and in situ UV/vis spectroscopye xperiments indicating that the one-electron reduced state displays al ong lifetime in solution. Overall, these results indicate the future potential of mechanochemistry in accessing synthetically challenging and functional curved p-systems. Scheme 1. Synthesis of curved p-systems.

Gold-mediated homogeneous catalysis is a powerful tool for construction of valuable molecules and has lately received growing attention. Whereas Au­(I)-catalyzed processes have become well established, those mediated by Au­(III) have so far barely been explored, and their mechanistic understanding remains basic. Herein, we disclose the combined NMR spectroscopic, single-crystal X-ray crystallographic, and computational (DFT) investigation of the Au­(III)-mediated alkoxycyclization of a 1,6-enyne in the presence of a bidentate pyridine-oxazoline ligand. The roles of the counterion, the solvent, and the type of Au­(III) complex have been assessed. Au­(III) is demonstrated to be the active catalyst in alkoxycyclization. Alkyne coordination to Au­(III) involves decoordination of the pyridine nitrogen and is the rate-limiting step.

Gold catalysis has become one of the fastest growing fields in chemistry, providing new organic transformations and offering excellent chemoselectivities under mild reaction conditions. Methodological developments have been driven by wide applicability in the synthesis of complex structures, whereas the mechanistic understanding of Au(III)-mediated processes remains scanty and have become the Achilles' heel of methodology development. Herein, the systematic investigation of the reactivity of bis(pyridine)-ligated Au(III) complexes is presented, based on NMR spectroscopic, X-ray crystallographic, and DFT data. The electron density of pyridines modulates the catalytic activity of Au(III) complexes in propargyl ester cyclopropanation of styrene. To avoid strain induced by a ligand with a nonoptimal nitrogen−nitrogen distance, bidentate bis(pyridine)−Au(III) complexes convert into dimers. For the first time, bis(pyridine)Au(I) complexes are shown to be catalytically active, with their reactivity being modulated by strain.