Synthesis and characterisation of an N-heterocyclic carbene with spatially-defined steric impact

Shaw, Paul and Kennedy, Alan R. and Nelson, David J. (2016) Synthesis and characterisation of an N-heterocyclic carbene with spatially-defined steric impact. Dalton Transactions. ISSN 1477-9226 (https://doi.org/10.1039/C6DT02100J)

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Abstract

The synthesis and co-ordination chemistry of a new ‘bulky yet flexible’ N-heterocyclic carbene (“IPaul”) is reported. This carbene has spatially-defined steric impact; steric maps show that two quadrants are very bulky while the other two are quite open. The electronic properties of this carbene are very similar to those of other 1,3-diarylimidazol-2-ylidenes. Copper, silver, iridium, and nickel complexes of the new ligand have been prepared. In solution, the ligand adopts two different conformations, while X-ray crystallographic analyses of the transition metal complexes suggest that the syn-conformer is preferred in the solid state due to intermolecular interactions. The copper complex of this new ligand has been shown to be highly-active in the hydrosilylation of carbonyl compounds, when compared to the analogous IPr, IMes, IPr* and IPr*OMe complexes.

ORCID iDs

Shaw, Paul, Kennedy, Alan R. ORCID logoORCID: https://orcid.org/0000-0003-3652-6015 and Nelson, David J. ORCID logoORCID: https://orcid.org/0000-0002-9461-5182;
CORE (COnnecting REpositories)