TY - JOUR
T1 - Commercial gold(III)complex supported on functionalized carbon materials as catalyst for cyclohexane hydrocarboxylation
AU - Pakrieva, Ekaterina
AU - Ribeiro, Ana P.C.
AU - Martins, Luísa M.D.R.S.
AU - Matias, Inês A.S.
AU - Carabineiro, Sónia A.C.
AU - Kolobova, Ekaterina
AU - Pombeiro, Armando J.L.
AU - Figueiredo, José L.
AU - Pestryakov, Alexey
PY - 2019/1/1
Y1 - 2019/1/1
N2 - The commercial dichloro(2-pyridinecarboxylato)gold(III)complex (1), anchored on different carbon materials, is reported for the first time as a catalyst in the cyclohexane hydrocarboxylation to cyclohexanecarboxylic acid. The reaction was carried out in the presence of CO and water, peroxodisulfate, at ca. 50 °C, with 1 in solution and anchored on carbon nanotubes, carbon xerogel or activated carbon, with three different surface chemistries: original forms (CNT, CX or AC, respectively), oxidized with HNO3 (-ox)or oxidized with HNO3 and subsequently treated with NaOH (-ox-Na). 1@CNT-ox-Na was the best catalyst, yielding up to 78% of cyclohexanecarboxylic with a selectivity of 99%. Recycling studies showed that the catalyst was stable up to 4 cycles, the first decrease (11%)on the hydrocarboxylation yield being observed on the 5th cycle. No leaching of gold was found into the solution. The hydrocarboxylation of other cycloalkanes (cyclopentane, cycloheptane and cyclooctane)was also tested in the best conditions found for cyclohexane, but the respective carboxylic acids were obtained in considerably lower yields, which can be explained by different stabilities of cycloalkyl radicals.
AB - The commercial dichloro(2-pyridinecarboxylato)gold(III)complex (1), anchored on different carbon materials, is reported for the first time as a catalyst in the cyclohexane hydrocarboxylation to cyclohexanecarboxylic acid. The reaction was carried out in the presence of CO and water, peroxodisulfate, at ca. 50 °C, with 1 in solution and anchored on carbon nanotubes, carbon xerogel or activated carbon, with three different surface chemistries: original forms (CNT, CX or AC, respectively), oxidized with HNO3 (-ox)or oxidized with HNO3 and subsequently treated with NaOH (-ox-Na). 1@CNT-ox-Na was the best catalyst, yielding up to 78% of cyclohexanecarboxylic with a selectivity of 99%. Recycling studies showed that the catalyst was stable up to 4 cycles, the first decrease (11%)on the hydrocarboxylation yield being observed on the 5th cycle. No leaching of gold was found into the solution. The hydrocarboxylation of other cycloalkanes (cyclopentane, cycloheptane and cyclooctane)was also tested in the best conditions found for cyclohexane, but the respective carboxylic acids were obtained in considerably lower yields, which can be explained by different stabilities of cycloalkyl radicals.
KW - Carbon materials functionalization
KW - Cyclohexane hydrocarboxylation
KW - Cyclohexanecarboxylic acid
KW - C̶[sbnd]H activation
KW - Dichloro(2-pyridinecarboxylato)gold(III)complex
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U2 - 10.1016/j.cattod.2019.05.050
DO - 10.1016/j.cattod.2019.05.050
M3 - Article
AN - SCOPUS:85066256893
JO - Catalysis Today
JF - Catalysis Today
SN - 0920-5861
ER -