Premium
2‐Benzoylpyridine Ligand Complexation with Gold Critical for Propargyl Ester‐Based Protein Labeling
Author(s) -
Lin Yixuan,
Vong Kenward,
Matsuoka Koji,
Tanaka Katsunori
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201802058
Subject(s) - propargyl , bioconjugation , chemistry , ligand (biochemistry) , combinatorial chemistry , catalysis , aryl , in vivo , stereochemistry , organic chemistry , biochemistry , receptor , biology , alkyl , microbiology and biotechnology
In previously reported work, Au III complexes coordinated with 2‐benzoylpyridine ligand, BPy‐Au, were prebound to a protein and used to discover a novel protein‐directed labeling approach with propargyl ester functional groups. In this work, further examination discovered that gold catalysts devoid of the 2‐benzoylpyridine ligand (e.g., NaAuCl4) had significantly reduced levels of protein labeling. Mechanistic investigations then revealed that BPy‐Au and propargyl esters undergo a rare example of C(sp 2 )−C(sp) aryl–alkynyl cross‐coupling, likely through spontaneous reductive elimination. Overall, these observations appear to suggest that BPy‐Au‐mediated, propargyl ester‐based protein labeling acts via an activated ester intermediate, which contributes to our understanding of this process and will aid the expansion/optimization of gold‐catalyst usage in future bioconjugation applications, especially in vivo.