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Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones

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Published on: February 7, 2019

Palladium-Catalyzed Cyclization of a Pyryne Precursor to Higher Pyrenylenes

Dennis Popp¹, Sven M Elbert¹, Chantal Barwig¹

¹Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.

Angewandte Chemie (International Ed. in English)

|March 7, 2023

Abstract:

The palladium catalyzed cyclotrimerization of ortho-silylaryl triflates as aryne precursors is meanwhile an established method to synthesize polycyclic aromatic hydrocarbons (PAHs) with triphenylene cores. During the palladium-catalyzed reaction of a pyrene with an o-silylaryl triflate moiety in the K-region higher homologues with central eight- and ten-membered rings (the pyrenylenes) were found, besides the expected trimer and a protocol was developed to isolate all members of this series. This unprecedented new class of PAHs was fully investigated by all means, including X-ray diffraction of single-crystals, UV/Vis and fluorescence spectroscopy and theoretical calculations. Supported by density-functional theory (DFT) calculations, a mechanism of all higher cyclooligomers is proposed.

Keywords:

Aryne Macrocycles Palladium Polycyclic Aromatic Hydrocarbon Pyrene

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