Abstract
Pd-mediated aromatic bromination is intriguing to synthetic and organometallic chemists due to both its synthetic utility and, more importantly, a proposed mechanism involving an uncommon Pd(IV)/Pd(II) catalytic cycle. Here, we report an X-ray snapshot observation of a Pd reaction center during a Pd-mediated aromatic bromination in a single crystal of a porous coordination network crystalline scaffold. Upon treatment of a single crystal with N-bromosuccinimide, sequential X-ray snapshots revealed that the aryl-Pd(II)-L species embedded in the network pores was converted to the brominated aryl product through a transient aryl-Pd(II)-Br species, which is normally unobservable because of its rapid dimerization into insoluble Pd 2(μ-Br)2 species. Though the reaction pathway may be biased by the crystalline state, the new X-ray snapshot method relies on crystalline flasks to provide important mechanistic insight.
Original language | English |
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Pages (from-to) | 6892-6895 |
Number of pages | 4 |
Journal | Journal of the American Chemical Society |
Volume | 136 |
Issue number | 19 |
DOIs | |
Publication status | Published - 2014 May 14 |
ASJC Scopus subject areas
- Catalysis
- Chemistry(all)
- Biochemistry
- Colloid and Surface Chemistry