Internal Alkynes – From Metal-mediated activation to redox active Macrocyles

Title: Internal Alkynes – From Metal-mediated activation to redox active Macrocyles

Speaker: Dr Marcus Korb, University of Western Australia

Abstract: The activation of functional groups and small molecules is crucial for developing new structural motifs and compounds. Internal alkynes (Ar-C≡C-Ar’) are widely used as pi-conjugated bridges and for the construction of rigid linear molecules. Their activation, however, is far less explored compared to terminal alkynes (Ar-C≡CH), which are readily functionalized through established catalytic transformations. Part 1 of this talk will focus on low-valent group 8 half-sandwich complexes [M(dppe)Cp]+ (M = Fe, Ru) as highly reactive intermediates, known for their ability to activate CH2Cl2 and H2. Their reaction with internal alkynes readily results in geminal vinylidene complexes (organometallic cumulenes) of type [M{=C=C(Ar)(Ar’)}(dppe)Cp]+, requiring migration of one of the substituents Ar/Ar’ along the unsaturated bond. The initial substrate limitations was recently overcome by my group allowing to convert even sterically demanding alkynes with Ar/Ar’ = pyrene and phenanthrene in high yield (89%). Part 2 of this talk will focus on ongoing investigations on Furan-3(2H)-ones, which is an emerging class of fluorescent dyes, as well as redox active organic macrocyles.

Bio: Dr. Marcus Korb is a research fellow at the University of Western Australia. He completed his undergraduate degree at Technical University Chemnitz under Prof. H. Lang, followed by a PhD in Inorganic Chemistry which he completed in 2017. After a short post-doctoral stay at TUC and the excellence cluster MERGE in Chemnitz, he moved to UWA in 2019 with a Fellowship from the Forrest Research Foundation. He established his independent group in 2023 through a DECRA, awarded by the Australian Research Council (ARC). In 2024, he received the EMCR award from the School of Molecular Sciences (UWA) and joined the EMCR Executive of the Australian Academy of Sciences.