Stille coupling via C-N bond cleavage.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 27686744.
- Also identified by DOI 10.1038/ncomms12937 and PMC identifier 5056441.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Cross-coupling is a fundamental reaction in the synthesis of functional molecules, and has been widely applied, for example, to phenols, anilines, alcohols, amines and their derivatives. Here we report the Ni-catalysed Stille cross-coupling reaction of quaternary ammonium salts via C-N bond cleavage. Aryl/alkyl-trimethylammonium salts [Ar/R-NMe<sub>3</sub>]<sup>+</sup> react smoothly with arylstannanes in 1:1 molar ratio in the presence of a catalytic amount of commercially available Ni(cod)<sub>2</sub> and imidazole ligand together with 3.0 equivalents of CsF, affording the corresponding biaryl with broad functional group compatibility. The reaction pathway, including C-N bond cleavage step, is proposed based on the experimental and computational findings, as well as isolation and single-crystal X-ray diffraction analysis of Ni-containing intermediates. This reaction should be widely applicable for transformation of amines/quaternary ammonium salts into multi-aromatics.