Reductive C(sp2)-N Elimination from Isolated Pd(IV) Amido Aryl Complexes Prepared Using H2O2 as Oxidant
Elikplim Abada1, Peter Y Zavalij1, Andrei N Vedernikov1
1Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States.
Journal of the American Chemical Society
|January 4, 2017
Summary
Palladium-catalyzed C-N coupling reactions efficiently produce N-substituted carbazoles from amidoarylpallada(II)cycles. The study details C(sp2)-N reductive elimination from palladium(IV) intermediates, advancing synthetic organic chemistry.
Area of Science:
- Organometallic Chemistry
- Synthetic Organic Chemistry
- Catalysis
Background:
- Palladium catalysis is crucial for C-N bond formation.
- Amidoaryl complexes offer unique reactivity pathways.
- Carbazole synthesis is important in materials science and pharmaceuticals.
Purpose of the Study:
- To investigate the synthesis of N-substituted carbazoles using palladium catalysis.
- To explore the mechanism of C-N coupling via palladium(IV) intermediates.
- To detail the C(sp2)-N reductive elimination from isolated palladium(IV) species.
Main Methods:
- Reaction of di-2-pyridyl ketone (dpk)-supported amidoarylpallada(II)cycles with hydrogen peroxide.
- Isolation and characterization of palladium(IV) intermediates using X-ray diffraction and NMR spectroscopy.
- Detailed mechanistic studies of C(sp2)-N reductive elimination.
Main Results:
- Efficient synthesis of N-R-substituted carbazoles (82-98% yield) via C-N coupling.
- Isolation and characterization of amidoaryl Pd(IV) complexes for R = MeSO2 and CF3SO2.
- First detailed study of C(sp2)-N reductive elimination from isolated amidoaryl Pd(IV) complexes.
Conclusions:
- Di-2-pyridyl ketone (dpk)-supported amidoarylpallada(II)cycles are effective precursors for carbazole synthesis.
- Palladium(IV) intermediates play a key role in the C-N coupling mechanism.
- This work provides significant mechanistic insight into palladium-catalyzed C-N bond formation.
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