TY - JOUR
T1 - Facile and efficient synthesis of C-hydroxycarboranes and C,C′-dihydroxycarboranes
AU - Ohta, Kiminori
AU - Goto, Tokuhito
AU - Yamazaki, Hiroto
AU - Pichierri, Fabio
AU - Endo, Yasuyuki
PY - 2007/5/14
Y1 - 2007/5/14
N2 - C-Hydroxylated carboranes, carboranols, have interesting properties resulting from their hydroxyl protons being highly acidic because of the electron-deficient nature of the carborane cage. We described here an efficient synthesis of C-hydroxycarboranes 2 and C,C′-dihydroxycarboranes 3 by the reaction of carboranyl lithium and trimethylborate, followed by oxidation with hydrogen peroxide in the presence of acetic acid, to afford the corresponding o-, m-, and p-hydroxycarboranes 2 and o-, m-, and p-dihydroxycarboranes 3 selectively in high yields through a one-pot procedure. The m- and p-carborane isomers of 2 and 3 were obtained in especially good yields (2b, 85%; 2c, 85%; 3b, 95%; 3c, 96%). DFT calculations were performed on the dihydroxycarboranes 3 to compare the geometrical features of the isomers at the same level of theory and to characterize their electronic and NMR spectroscopic (13C chemical shift) properties.
AB - C-Hydroxylated carboranes, carboranols, have interesting properties resulting from their hydroxyl protons being highly acidic because of the electron-deficient nature of the carborane cage. We described here an efficient synthesis of C-hydroxycarboranes 2 and C,C′-dihydroxycarboranes 3 by the reaction of carboranyl lithium and trimethylborate, followed by oxidation with hydrogen peroxide in the presence of acetic acid, to afford the corresponding o-, m-, and p-hydroxycarboranes 2 and o-, m-, and p-dihydroxycarboranes 3 selectively in high yields through a one-pot procedure. The m- and p-carborane isomers of 2 and 3 were obtained in especially good yields (2b, 85%; 2c, 85%; 3b, 95%; 3c, 96%). DFT calculations were performed on the dihydroxycarboranes 3 to compare the geometrical features of the isomers at the same level of theory and to characterize their electronic and NMR spectroscopic (13C chemical shift) properties.
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U2 - 10.1021/ic062025q
DO - 10.1021/ic062025q
M3 - Article
C2 - 17429958
AN - SCOPUS:34249674826
VL - 46
SP - 3966
EP - 3970
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 10
ER -