Novel gold(I) "click" carbene(1,2,3-triazolylidene) complexes have been synthesised, characterised and exploited for the self-assembly of a metallomacrocycle and as precatalysts for gold(I)-catalysed reactions.

The [Ni(IMes)2]-catalyzed transformation of fluoroarenes into arylboronic acid pinacol esters via C-F bond activation and transmetalation with bis(pinacolato)diboron (B2pin2) is reported. Various partially fluorinated arenes with different degrees of fluorination were converted into their corresponding boronate esters.

N-heterocyclic carbenes (NHCs) and cyclic (alkyl)(amino)carbenes (CAACs) are of great interest, as their electronic and steric properties provide a unique class of ligands and organocatalysts. Herein, substitution reactions involving novel carbonyl complexes of rhodium and nickel were studied to provide a deeper understanding of the fundamental electronic factors characterizing CAAC(methyl) , which were compared with the large array of data available for NHC and sterically more demanding CAAC ligands.

The first synthesis of cyclic (alkyl)(amino)carbenes (cAACs) was reported in 2005, and since then this class of carbenes has been on a victory tour in main-group-element and transition-metal chemistry. CAACs are easy to synthesize and among the most nucleophilic (σ-donating) and simultaneously most electrophilic (π-accepting) carbenes known to date. These properties have led to a vast number of applications of cAACs in main-group-element chemistry in, for example, the activation of small-molecule compounds and enthalpically strong bonds, as well as in the stabilization of highly reactive main-group- [a] .Udo's major research interests lie in the fields of main-group-element and transition-metal chemistry with an emphasis on the chemistry of NHCs and related species in inorganic chemistry, the catalytic activation of small-molecule compounds and the manipulation of fluorinated organic molecules in the coordination sphere of transition metals.

We report the isolation and detailed structural characterization, by solid-state and solution NMR spectroscopy, of the neutral mono- and bis-NHC adducts of bis(catecholato)diboron (B2 cat2 ). The bis-NHC adduct undergoes thermally induced rearrangement, forming a six-membered -B-C=N-C=C-N-heterocyclic ring via C-N bond cleavage and ring expansion of the NHC, whereas the mono-NHC adduct is stable. Bis(neopentylglycolato)diboron (B2 neop2 ) is much more reactive than B2 cat2 giving a ring expanded product at room temperature, demonstrating that ring expansion of NHCs can be a very facile process with significant implications for their use in catalysis.