X.-F. Xia et al. / Tetrahedron xxx (2015) 1e4
3
resulting mixture was quenched with water and extracted twice
with EtOAc (10 mL). The combined organic extracts were washed
with brine (10 mL), dried over Na2SO4 and concentrated. Purifica-
tion of the crude product by flash column chromatography afforded
the product 3 (petroleum ether/ethyl acetate as eluent (6:1)).
3a, mp¼180e181 ꢀC, white solid, 1H NMR (400 MHz, CDCl3):
7.66e7.79 (m, 8H), 7.55e7.58 (m, 2H), 7.34e7.36 (m, 3H), 5.85e5.87
(m, 1H), 4.91e4.95 (m, 1H), 4.54e4.58 (m, 1H); 13C NMR (100 MHz,
CDCl3): 163.3, 162.9, 134.4, 134.2, 128.6, 128.0, 123.4, 123.3, 85.6,
79.2; HRMS (ESI) m/z: calcd for C24H16N2O6Na: MþNaþ¼451.0906;
found: 451.0901. IR (cmꢁ1): 2924, 1788, 1733, 1653, 1540, 1462,
1394, 1375, 1187, 1131, 1076, 1021, 972, 878, 700.
3b, dr¼5:2, mp¼174e176 ꢀC, 1H NMR (400 MHz, CDCl3):
7.82e7.85 (m, 0.9H), 7.65e7.78 (m, 10H), 7.59e7.61 (m, 2.9H),
7.27e7.32 (m, 4.2H), 5,83 (d, J¼8.0 Hz, 0.4H), 5.66e5.67 (m, 1.0H),
4.98e5.01 (m, 0.4H), 4.88e4.95 (m, 1.0H), 1.69 (d, J¼4.0 Hz, 3.0H),
1.24 (d, J¼8.0 Hz, 1.2H); 13C NMR (100 MHz, CDCl3): 163.6, 163.2,
134.4, 134.3, 134.2, 128.1, 123.5, 123.4, 123.3, 89.4, 88.6, 84.6, 15.7,
14.5; IR (cmꢁ1): 3070, 2937, 1790, 1731, 1466, 1373, 1188, 1126, 1081,
1016, 979, 877, 700; HRMS (ESI) m/z: calcd for C25H18N2O6Na:
MþNaþ¼465.1063; found: 465.1052.
Scheme 4. Proposed mechanism.
Last, the product 3a can be easily transformed into 1-
phenylethane-1,2-diol 4 in moderate yield by cleavage of the
NeO bond with Mo(CO)6, and 1,2-diol 4 was obtained in 65% yield
(Scheme 5).6c
3c, mp¼112e114 ꢀC, 1H NMR (400 MHz, CDCl3): 7.70e7.82 (m,
8H), 7.44e7.53 (m, 4H), 5.79e5.82 (m, 0.92H), 4.85e4.88 (m, 1.0H),
4.53e4.57 (m, 1.0H); 13C NMR (100 MHz, CDCl3): 163.4, 163.1, 134.5,
133.3, 132.1, 131.8, 129.9, 129.8, 128.8, 128.7, 123.9, 123.6, 123.5, 84.9,
78.8; IR (cmꢁ1): 1790, 1732, 1373, 1188, 1133, 1082, 976, 876, 699;
HRMS (ESI) m/z: calcd for C24H1581BrN2O6Na: MþNaþ¼530.9991;
found: 530.9967.
3d, mp¼106e108 ꢀC, 1H NMR (400 MHz, CDCl3): 7.72e7.29 (m,
8.0H), 7.58e7.61 (m, 2.0H), 7.04e7.08 (m, 2.0H), 5.81e5.84 (m, 1H),
4.87e4.92 (m, 1H), 4.55e4.59 (m, 1H); 13C NMR (100 MHz, CDCl3):
163.4, 163.0, 134.5, 134.5, 134.3, 128.7, 123.4, 115.7, 115.5, 84.8, 78.9;
IR (cmꢁ1): 1787, 1732, 1607, 1513, 1372, 1223, 1187, 1126, 1079, 975,
Scheme 5. Transformation of the product 3a.
876, 698; HRMS (ESI) m/z: calcd for
C24H15FN2O6Na:
3. Conclusions
MþNaþ¼469.0812; found: 469.0798.
3e, mp¼107e109 ꢀC, 1H NMR (400 MHz, CDCl3): 7.69e7.81 (m,
8.0H), 7.54e7.57 (m, 2H), 7.33e7.35 (m, 2H), 5.80e5.83 (m, 1H),
4.85e4.90 (m, 1H), 4.54e4.58 (m, 1H); 13C NMR (100 MHz, CDCl3):
163.4,163.0,135.6,134.5,134.3,132.7,128.7,123.6,123.5,123.4, 84.9,
78.8; IR (cmꢁ1): 2925, 1790, 1732, 1373, 1187, 1129, 1081, 1016, 975,
In conclusion, we have developed an efficient copper-catalyzed
highly 1,2-dihydroxylamination of olefins using PhI(OAc)2 as oxi-
dant. A radical addition process was involved in this transformation
with the formation of two CeO bonds in one step. The product can
be further transformed into diol under the reductive conditions.
Further investigations on the mechanism and synthetic application
of these reactions are ongoing in our group.
876, 699; HRMS (ESI) m/z: calcd for
C24H15ClN2O6Na:
MþNaþ¼485.0516; found: 485.0538.
3f, oil, 1H NMR (400 MHz, CDCl3): 7.86 (d, J¼8.0 Hz, 1H),
7.71e7.83 (m, 8H), 7.29e7.36 (m, 3H), 6.30 (d, J¼8.0 Hz, 1H),
4.87e4.92 (m, 1H), 4.50e4.53 (m, 1H); 13C NMR (100 MHz, CDCl3):
163.3, 162.9, 134.4, 132.0, 130.3, 129.5, 128.9, 128.8, 128.7, 127.1,
123.5, 123.4, 82.4, 79.3; IR (cmꢁ1): 3066, 2937, 1790, 1738, 1731,
1467, 1372, 1187, 1130, 1081, 1017, 976, 912, 877, 700; HRMS (ESI) m/
z: calcd for C24H15ClN2O6Na: MþNaþ¼485.0516; found: 485.0556.
3g, mp¼95e97 ꢀC, 1H NMR (400 MHz, CDCl3): 7.70e7.81 (m,
9H), 7.57 (d, J¼8.0 Hz, 1H), 7.47e7.49 (m, 1H), 7.25e7.29 (m, 1H),
5.77e5.79 (m, 1H), 4.85e4.88 (m, 1H), 4.53e4.57 (m, 1H); 13C NMR
(100 MHz, CDCl3): 163.3,162.9,136.5,134.5,134.3,132.6,131.1,130.1,
128.8, 128.6, 126.6, 123.5, 122.5, 84.9, 79.1; IR (cmꢁ1): 3081, 2948,
1790, 1731, 1467, 1372, 1187, 1130, 1081, 1017, 976, 876, 700; HRMS
(ESI) m/z: calcd for C24H15BrN2O6Na: MþNaþ¼529.0011; found:
529.0049.
4. Experimental section
4.1. General information
Column chromatography was carried out on silica gel
(200e300 mesh). Unless noted, 1H NMR spectra were recorded on
400 MHz in CDCl3, 13C NMR spectra were recorded on 100 MHz in
CDCl3. IR spectra were recorded on an FT-IR spectrometer and only
major peaks are reported in cmꢁ1. Melting points were determined
on a microscopic apparatus and were uncorrected. All new prod-
ucts were further characterized by HRMS (high resolution mass
spectra), high resolution mass spectrometry (HRMS) spectra was
obtained on a micrOTOF-Q instrument equipped with an ESI
source; copies of their 1H NMR and 13C NMR spectra are provided.
Commercially available reagents and solvents were used without
further purification.
3h, mp¼162e164 ꢀC, 1H NMR (400 MHz, CDCl3): 7.64e7.73 (m,
8H), 7.30e7.32 (m, 4H), 7.12e7.14 (m, 6H), 6.08 (s, 2H); 13C NMR
(100 MHz, CDCl3): 163.2,134.2,133.7, 128.9,128.7,127.9,123.3, 89.5;
IR (cmꢁ1): 3064, 3035, 1790, 1736, 1734, 1372, 1187, 1129, 1081, 980,
4.1.1. Typical procedure for the synthesis of products 3. To a solution
of N-hydroxyphthalimide (2, 0.66 mmol, 107.6 mg) in DCE (2.0 mL)
was added styrene (1, 0.3 mmol), CuCl (10%, 0.03 mmol, 3.0 mg),
PhI(OAc)2 (212.5 mg, 2.2 equiv, 0.66 mmol). The reaction mixture
was then stirred for 12 h at 80 ꢀC in air. After the reaction, the
876, 699; HRMS (ESI) m/z: calcd for
C30H20N2O6Na:
MþNaþ¼527.1219; found: 527.1242.
3i, oil, 1H NMR (400 MHz, CDCl3): 7.87e7.89 (m, 2H), 7.68e7.83
(m, 8H), 7.39e7.41 (m, 2H), 7.32e7.36 (m, 1H), 4.73e4.79 (m, 2H),
2.10 (s, 3H); 13C NMR (100 MHz, CDCl3): 165.1, 162.8, 138.6, 134.3,