Neutralising antibodies after COVID-19 vaccination in UK haemodialysis patients

Vaccination against COVID-19 induces highly protective immune responses in most people. As some countries switch from suppression to acceptance of transmission of SARS-CoV-2 within a largely vaccinated adult population, vulnerable patient groups that have not mounted adequate immune responses to vaccination might experience significant morbidity and mortality. There is an urgent need to identify such patient groups and to optimise medical advice and vaccination strategies for them

Use of ring-expanded diamino- and diamidocarbene ligands in copper catalyzed azide-alkyne "click" reactions

The two-coordinate ring-expanded N-heterocyclic carbene copper­(I) complexes [Cu­(RE-NHC)₂]⁺ (RE-NHC = 6-Mes, 7-<i>o</i>-Tol, 7-Mes) have been prepared and shown to be effective catalysts under neat conditions for the 1,3-dipolar cycloaddition of alkynes and azides. In contrast, the cationic diamidocarbene analogue [Cu­(6-MesDAC)₂]⁺ and the neutral species [(6-MesDAC)­CuCl]₂ and [(6-MesDAC)₂(CuCl)₃] show good activity when the catalysis is performed on water

Mechanistic Studies of the Rhodium NHC Catalyzed Hydrodefluorination of Polyfluorotoluenes

The six-membered-ring NHC complexes Rh­(6-NHC)­(PPh₃)₂H (6-NHC <b>=</b> 6-ⁱPr (<b>1</b>), 6-Et (<b>2</b>), 6-Me (<b>3</b>)) have been employed in the catalytic hydrodefluorination (HDF) of C₆F₅CF₃ and 2-C₆F₄HCF₃. Stoichiometric studies showed that <b>1</b> reacted with C₆F₅CF₃ at room temperature to afford <i>cis</i>- and <i>trans</i>-phosphine isomers of Rh­(6-ⁱPr)­(PPh₃)₂F (<b>4</b>), which re-form <b>1</b> upon heating with Et₃SiH. Although up to three consecutive HDF steps prove possible with C₆F₅CF₃, the ultimate effectiveness of the catalysts is limited by their propensity to undergo C–H activation of partially fluorinated toluenes to give, for example, Rh­(6-ⁱPr)­(PPh₃)₂(C₆F₄CF₃) (<b>7</b>), which was isolated and structurally characterized

Copper Diamidocarbene Complexes: Characterization of Monomeric to Tetrameric Species

Treatment of CuCl with 1 equiv of the in situ prepared <i>N</i>-mesityl-substituted diamidocarbene 6-MesDAC produced a mixture of the dimeric and trimeric copper complexes [(6-MesDAC)­CuCl]₂ (<b>1</b>) and [(6-MesDAC)₂(CuCl)₃] (<b>2</b>). Combining CuCl with isolated, free 6-MesDAC in 1:1 and 3:2 ratios gave just <b>1</b> and <b>2</b>, respectively, while increasing the ratio to >5:1 allowed the isolation of small amounts of the tetrameric copper complex [(6-MesDAC)₂(CuCl)₄] (<b>3</b>). Efforts to bring about metathesis reactions of <b>1</b> with MO^tBu (M = Li, Na, K) proved successful only for M = Li to afford the spectroscopically characterized ate product [(6-MesDAC)­CuCl·LiO^tBu·2THF] (<b>5</b>). Attempts to crystallize this species instead gave a 1:1 mixture of <b>1</b> and the monomer [(6-MesDAC)­CuCl] (<b>6</b>). The X-ray structures of <b>1</b>–<b>3</b> and <b>1</b> + <b>6</b>, along with the cation [Cu­(6-MesDAC)₂]⁺ (<b>4</b>), have been determined

Mesoionic triazolylidene nickel complexes: synthesis, ligand lability, and catalytic C–C bond formation activity

A set of triazolylidene (trz) nickel(II) complexes [NiCpX(trz)] was synthesized by a direct metalation of the corresponding triazolium salt with nickelocene, NiCp2. While at short reaction times and in the presence of a coordinating anion X the mono-carbene complex is preferably formed, long reaction times induce the gradual transformation of [NiCpX(trz)] to the bis-carbene complexes [Ni(Cp)(trz)2]+. Kinetic analyses lend strong support to a consecutive pathway involving triazolylidene dissociation from [NiCpX(trz)] en route to the bis-carbene complex. Similar carbene transfer is observed in a solid-state reaction upon heating the complex [NiCpI(trz)] in vacuo, which induces disproportionation to [NiI2(trz)2] and NiCp2, confirming that the Ni–C(trz) bond is kinetically labile. The complexes [Ni(Cp)(trz)2]+ and [NiCpX(trz)] were both efficient catalyst precursors for Suzuki–Miyaura cross-coupling of aryl bromides and phenylboronic acid, with turnover frequencies exceeding 228 h–1. Complex degradation after short reaction times, identified in separate experiments, prohibits high turnover numbers, and for high conversions, repetitive additions of triazolylidene nickel complex and phenylboronic acid are necessary.European Research Counci