The reaction of complex (SIPr)PdCl 2 (TEA) (SIPr = 1,3-bis(2,6-diisopropylphenyl)-2-imidazolidinylidene, TEA = triethylamine) with tertbutylammoniun chloride (TBAC) at room temperature affords the new ionic complex [TBA][(SIPr)-PdCl 3 ] in quantitative yield. The activity of this complex as a precatalyst for Heck coupling reactions has been explored. Experimental results and DFT calculations support a plausible anionic Amatore−Jutand-type mechanism for the Heck reaction involving anionic (NHC)-palladium(0) catalytic species.

The global spread of the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has called for an urgent need for dedicated antiviral therapeutics. Metal complexes are commonly underrepresented in compound libraries that are used for screening in drug discovery campaigns, however, there is growing evidence for their role in medicinal chemistry. Based on previous results, we have selected more than 100 structurally diverse metal complexes for profiling as inhibitors of two relevant SARS‐CoV‐2 replication mechanisms, namely the interaction of the spike (S) protein with the ACE2 receptor and the papain‐like protease PL pro . In addition to many well‐established types of mononuclear experimental metallodrugs, the pool of compounds tested was extended to approved metal‐based therapeutics such as silver sulfadiazine and thiomersal, as well as polyoxometalates (POMs). Among the mononuclear metal complexes, only a small number of active inhibitors of the S/ACE2 interaction was identified, with titanocene dichloride as the only strong inhibitor. However, among the gold and silver containing complexes many turned out to be very potent inhibitors of PL pro activity. Highly promising activity against both targets was noted for many POMs. Selected complexes were evaluated in antiviral SARS‐CoV‐2 assays confirming activity for gold complexes with N‐heterocyclic carbene (NHC) or dithiocarbamato ligands, a silver NHC complex, titanocene dichloride as well as a POM compound. These studies might provide starting points for the design of metal‐based SARS‐CoV‐2 antiviral agents.

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The use of a custom-made palladium complex for the telomerisation of isoprene with alcohols under green conditions is described.