TY - JOUR
T1 - Diversion of Catalytic C-N Bond Formation to Catalytic Oxidation of NH3 through Modification of the Hydrogen Atom Abstractor
AU - Dunn, Peter L.
AU - Johnson, Samantha I.
AU - Kaminsky, Werner
AU - Bullock, R. Morris
PY - 2020/2/19
Y1 - 2020/2/19
N2 - We report that (TMP)Ru(NH3)2 (TMP = tetramesitylporphryin) is a molecular catalyst for oxidation of ammonia to dinitrogen. An aryloxy radical, tri-tert-butylphenoxyl (ArO·), abstracts H atoms from a bound ammonia ligand of (TMP)Ru(NH3)2, leading to the discovery of a new catalytic C-N coupling to the para position of ArO· to form 4-amino-2,4,6-tri-tert-butylcyclohexa-2,5-dien-1-one. Modification of the aryloxy radical to 2,6-di-tert-butyl-4-tritylphenoxyl radical, which contains a trityl group at the para position, prevents C-N coupling and diverts the reaction to catalytic oxidation of NH3 to give N2. We achieved 125 ± 5 turnovers at 22 °C for oxidation of NH3, the highest turnover number (TON) reported to date for a molecular catalyst.
AB - We report that (TMP)Ru(NH3)2 (TMP = tetramesitylporphryin) is a molecular catalyst for oxidation of ammonia to dinitrogen. An aryloxy radical, tri-tert-butylphenoxyl (ArO·), abstracts H atoms from a bound ammonia ligand of (TMP)Ru(NH3)2, leading to the discovery of a new catalytic C-N coupling to the para position of ArO· to form 4-amino-2,4,6-tri-tert-butylcyclohexa-2,5-dien-1-one. Modification of the aryloxy radical to 2,6-di-tert-butyl-4-tritylphenoxyl radical, which contains a trityl group at the para position, prevents C-N coupling and diverts the reaction to catalytic oxidation of NH3 to give N2. We achieved 125 ± 5 turnovers at 22 °C for oxidation of NH3, the highest turnover number (TON) reported to date for a molecular catalyst.
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U2 - 10.1021/jacs.9b13706
DO - 10.1021/jacs.9b13706
M3 - Article
C2 - 32009401
AN - SCOPUS:85080121028
VL - 142
SP - 3361
EP - 3365
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 7
ER -