Reductive C(sp2)-N Elimination from Isolated Pd(IV) Amido Aryl Complexes Prepared Using H2O2 as Oxidant.

Di-2-pyridyl ketone (dpk)-supported amidoarylpallada(II)cycles derived from various 2-(N-R-amino)biphenyls (R = H, Me, CF3CO, MeSO2, CF3SO2) react with hydrogen peroxide in MeOH, THF, MeCN or AcOH to form the corresponding C-N coupled products, N-R-substituted carbazoles, in 82-98% yield. For R = MeSO2 and CF3SO2, the corresponding reaction intermediates, amidoaryl Pd(IV) complexes were isolated and characterized by single crystal X-ray diffraction and/or NMR spectroscopy. For the first time, the C(sp2)-N reductive elimination from isolated amidoaryl Pd(IV) complexes has been studied in detail.