H. Bao et al. / Tetrahedron xxx (xxxx) xxx
5
O) cmꢁ1
;
1H NMR (CDCl3, 500 MHz):
d
8.37 (dd, J1 ¼8.0 Hz,
(neat):
n
¼ 1667 (C]O) cmꢁ1; 1H NMR (CDCl3, 500 MHz):
d
8.27 (dd,
J2 ¼ 1.5 Hz, 1H), 8.20 (d, J ¼ 2.0 Hz, 1H), 7.75e7.71 (m, 1H), 7.63 (dd,
J1 ¼8.5 Hz, J2 ¼ 2.0 Hz,1H), 7.50 (d, J ¼ 8.0 Hz,1H), 7.45 (d, J ¼ 8.5 Hz,
1H), 7.40e7.37 (m, 1H), 3.12e3.03 (m, 1H), 1.34 (d, J ¼ 7.0 Hz, 6H);
J1 ¼8.0 Hz, J2 ¼ 1.5 Hz, 1H), 8.13 (d, J ¼ 2.0 Hz, 1H), 7.73e7.70 (m,
1H), 7.54 (dd, J1 ¼9.0 Hz, J2 ¼ 2.5 Hz, 1H), 7.49 (d, J ¼ 9.0 Hz, 1H),
7.45 (d, J ¼ 8.5 Hz, 1H), 7.37 (t, J ¼ 7.5 Hz, 1H); 13C NMR (CDCl3,
13C NMR (CDCl3, 125 MHz):
d
177.4, 156.2, 154.6, 144.7, 134.6, 133.8,
125 MHz): d 176.1, 156.0, 154.1, 145.0, 135.2, 128.0, 126.7, 124.3,
126.8, 123.7, 123.5, 121.9, 121.6, 118.0, 117.9, 33.7, 24.0; HRMS (ESI)
122.4, 121.1, 120 (d, J ¼ 256.7 Hz),120.0, 118.3, 118.0; HRMS (ESI) for
for C16H15O2 [MþH]þ: calcd. 239.1067, found 239.1061.
C
14H8F3O3 [MþH]þ: calcd. 281.0420, found 281.0416.
4.3.3. 2-(tert.-butyl)-9H-xanthen-9-one (2c) [14]
4.3.9. 1-Chloro-9H-xanthen-9-one (2i) [18]
Purification by column chromatography (petroleum ether/
Purification by column chromatography (petroleum ether/
EtOAc, 20/1) as a white solid (46.2 mg, 61%); m.p. 110e112 ꢀC (lit.
EtOAc, 20/1) as a white solid (31.3 mg, 45%); m.p. 131e133 ꢀC (lit.
[14] mp 114e115 ꢀC); IR (neat):
n
¼ 1659 (C]O) cmꢁ1
;
1H NMR
[18] m.p. 134e136 ꢀC); IR (neat):
n
¼ 1663 (C]O) cmꢁ1
;
1H NMR
(CDCl3, 500 MHz):
d
8.36 (dd, J1 ¼8.0 Hz, J2 ¼ 1.5 Hz, 1H), 8.34 (d,
(CDCl3, 500 MHz):
d
8.28 (dd, J1 ¼8.0 Hz, J2 ¼ 1.5 Hz, 1H), 7.71e7.67
J ¼ 2.5 Hz, 1H), 7.79 (dd, J1 ¼9.0 Hz, J2 ¼ 2.5 Hz, 1H), 7.72e7.69 (m,
(m, 1H), 7.54 (t, J ¼ 8.0 Hz, 1H), 7.42e7.34 (m, 4H); 13C NMR (CDCl3,
1H), 7.47 (d, J ¼ 9.0 Hz, 1H), 7.43 (d, J ¼ 9.0 Hz, 1H), 7.39e7.34 (m,
125 MHz):
d 175.8, 157.7, 154.9, 134.8, 134.4, 133.7, 127.0, 127.0,
1H), 1.41 (s, 9H); 13C NMR (CDCl3, 125 MHz):
d 177.4, 156.2, 154.3,
124.2, 122.4, 118.9, 117.4, 117.2. Analytical data of another
regioisomer 3-chloro-9H-xanthen-9-one (2iʹ) [7f]: 2iʹ was purified
by column chromatography (petroleum ether/EtOAc, 20/1) as a
white solid (20.8 mg, 30%); m.p. 129e130 ꢀC (lit. [7f] m.p.
147.1, 134.6, 132.7, 126.7, 123.7, 122.4, 121.9, 121.2, 117.9, 117.6, 34.7,
31.4.
4.3.4. 2-Phenyl-9H-xanthen-9-one (2d) [15]
128.2e129.6 ꢀC); IR (neat):
500 MHz):
n
¼ 1670 (C]O) cmꢁ1
;
1H NMR (CDCl3,
Purification by column chromatography (petroleum ether/
d
8.24 (dd, J1 ¼8.0 Hz, J2 ¼ 1.5 Hz, 1H), 8.19 (d, J ¼ 8.5 Hz,
EtOAc, 20/1) as a white solid (39.2 mg, 48%); m.p. 145e147 ꢀC (lit.
1H), 7.69e7.65 (m, 1H), 7.40e7.37 (m, 2H), 7.35e7.31 (m, 1H), 7.27
[15] mp 141e141.5 ꢀC); IR (neat):
n
¼ 1658 (C]O) cmꢁ1
;
1H NMR
(dd, J1 ¼8.5 Hz, J2 ¼ 1.5 Hz, 1H); 13C NMR (CDCl3, 125 MHz):
d 176.0,
(CDCl3, 500 MHz):
d
8.57 (d, J ¼ 2.5 Hz, 1H), 8.38 (dd, J1 ¼8.0 Hz,
156.1,155.9,140.7,134.9,128.0,126.6,124.7,124.2,121.6,120.3,117.9,
117.8.
J2 ¼ 1.5 Hz, 1H), 7.97 (dd, J1 ¼8.5 Hz, J2 ¼ 2.5 Hz, 1H), 7.76e7.72 (m,
1H), 7.70e7.68 (m, 2H), 7.57 (d, J ¼ 8.5 Hz, 1H), 7.52e7.48 (m, 3H),
7.42e7.38 (m, 2H); 13C NMR (CDCl3, 125 MHz):
d 177.2, 156.2, 155.5,
139.4,137.0,134.8,133.6, 129.0,127.7,127.1,126.8,124.5,124.0,121.9,
121.8, 118.5, 118.0; HRMS (ESI) for C19H13O2 [MþH]þ: calcd.
273.0910, found 273.0915.
4.3.10. 1-Trifluoromethyl-9H-xanthen-9-one (2j)
Purification by column chromatography (petroleum ether/
EtOAc, 20/1) as white solid (43.6 mg, 55%); m.p. 173e175 ꢀC; IR
(neat):
n
¼ 1673 (C]O) cmꢁ1; 1H NMR (CDCl3, 500 MHz):
d 8.32 (dd,
4.3.5. 2-Fluoro-9H-xanthen-9-one (2e) [16]
J1 ¼8.0 Hz, J2 ¼ 1.5 Hz, 1H), 7.81e7.72 (m, 4H), 7.47 (d, J ¼ 8.0 Hz,
Purification by column chromatography (petroleum ether/
1H), 7.41e7.38 (m, 1H); 13C NMR (CDCl3, 125 MHz):
d 174.7, 157.6,
EtOAc, 20/1) as a white solid (54.0 mg, 84%); m.p. 161e163 ꢀC (lit.
154.8, 135.0, 133.5, 129.3 (q, J ¼ 33.8 Hz), 127.1, 124.5, 123.5 (q,
J ¼ 7.5 Hz), 123.3, 123.2 (q, J ¼ 272.5 Hz), 122.5, 119.3, 117.4; HRMS
(ESI) for C14H8F3O2 [MþH]þ: calcd. 265.0471, found 265.0467.
Analytical data of another regioisomer 3-trifluoromethyl-9H-
xanthen-9-one (2jʹ): 2jʹ was purified by column chromatography
(petroleum ether/EtOAc, 20/1) as a white solid (26.2 mg, 33%); m.p.
[16] m.p. 286e287 ꢀC); IR (neat):
n
¼ 1664 (C]O) cmꢁ1
;
1H NMR
(CDCl3, 500 MHz):
d
8.24 (dd, J1 ¼8.0 Hz, J2 ¼ 1.5 Hz, 1H), 7.88 (dd,
J1 ¼8.5 Hz, J2 ¼ 3.0 Hz, 1H), 7.69e7.66 (m, 1H), 7.42e7.36 (m, 3H),
7.33 (t, J ¼ 7.5 Hz, 1H); 13C NMR (CDCl3, 125 MHz):
d 176.3 (d,
J ¼ 2.5 Hz), 159.6 (d, J ¼ 243.8 Hz), 156.0, 152.2 (d, J ¼ 1.3 Hz), 134.9,
126.5, 124.0, 122.8 (d, J ¼ 25 Hz), 122.5 (d, J ¼ 7.5 Hz), 120.9, 119.9 (d,
J ¼ 7.5 Hz), 117.9, 111.2 (d, J ¼ 23.8 Hz).
91e93 ꢀC; IR (neat):
500 MHz):
n
¼ 1675 (C]O) cmꢁ1
;
1H NMR (CDCl3,
d
8.44 (d, J ¼ 8.5 Hz, 1H), 8.33 (dd, J1 ¼8.0 Hz, J2 ¼ 1.5 Hz,
1H), 7.79e7.74 (m, 2H), 7.60 (d, J ¼ 8.5 Hz, 1H), 7.51 (d, J ¼ 8.5 Hz,
4.3.6. 2-Chloro-9H-xanthen-9-one (2f) [7i]
1H), 7.42 (t, J ¼ 7.5 Hz, 1H); 13C NMR (CDCl3, 125 MHz):
d 176.3,
Purification by column chromatography (petroleum ether/
156.2, 155.6, 136.1 (q, J ¼ 32.5 Hz), 135.5, 128.0, 126.8, 124.6, 123.9,
123.1 (q, J ¼ 271.3 Hz), 121.8, 120.2 (q, J ¼ 3.8 Hz), 118.1, 115.9 (q,
J ¼ 3.8 Hz); HRMS (ESI) for C14H8F3O2 [MþH]þ: calcd. 265.0471,
found 265.0469.
EtOAc, 20/1) as a white solid (54.0 mg, 78%); m.p. 170e171 ꢀC (lit.
[7i] m.p. 169e171 ꢀC); IR (neat):
n
¼ 1664 (C]O) cmꢁ1
;
1H NMR
(CDCl3, 500 MHz):
J ¼ 2.5 Hz, 1H), 7.71e7.68 (m, 1H), 7.59 (dd, J1 ¼8.5 Hz, J2 ¼ 2.5 Hz,
1H), 7.42 (d, J ¼ 8.0 Hz, 1H), 7.38 (d, J ¼ 9.0 Hz, 1H), 7.35 (t, J ¼ 7.5 Hz,
d
8.26 (dd, J1 ¼8.0 Hz, J2 ¼ 1.5 Hz, 1H), 8.21 (d,
4.3.11. 1-Fluoro-9H-xanthen-9-one (2k)
1H); 13C NMR (CDCl3, 125 MHz):
d 175.9, 155.9, 154.4, 135.1, 134.8,
Purification by column chromatography (petroleum ether/
129.6, 126.7, 125.9, 124.2, 122.6, 121.3, 119.7, 117.9.
EtOAc, 20/1) as a white solid (43.1 mg, 67%); m.p. 144e146 ꢀC; IR
(neat):
n
¼ 1670 (C]O) cmꢁ1; 1H NMR (CDCl3, 500 MHz):
d 8.30 (dd,
4.3.7. 2-Bromo-9H-xanthen-9-one (2g) [17]
J1 ¼8.0 Hz, J2 ¼ 1.5 Hz, 1H), 7.73e7.69 (m, 1H), 7.66e7.62 (m, 1H),
7.44 (d, J ¼ 8.0 Hz, 1H), 7.40e7.36 (m, 1H), 7.28 (d, J ¼ 8.5 Hz, 1H),
Purification by column chromatography (petroleum ether/
EtOAc, 20/1) as a white solid (57.8 mg, 70%); m.p. 115e117 ꢀC (lit.
7.04e7.00 (m, 1H); 13C NMR (125 MHz, CDCl3):
d 175.3 (d,
[17] m.p. 149.3e150.5 ꢀC); IR (neat):
n
¼ 1661 (C]O) cmꢁ1
;
1H
J ¼ 1.3 Hz), 161.5 (d, J ¼ 263.8 Hz), 157.1 (d, J ¼ 3.8 Hz), 155.3, 134.9,
134.7 (d, J ¼ 11.3 Hz), 126.7, 124.2, 122.3, 117.6, 113.8 (d, J ¼ 3.8 Hz),
112.4 (d, J ¼ 10 Hz), 110.8 (d, J ¼ 21.3 Hz); HRMS (ESI) for C13H8FO2
[MþH]þ: calcd. 215.0503, found 215.0508.
NMR(CDCl3, 500 MHz):
d
8.44 (d, J ¼ 2.5 Hz, 1H), 8.32 (dd,
J1 ¼8.0 Hz, J2 ¼ 1.5 Hz, 1H), 7.79 (dd, J1 ¼9.0 Hz, J2 ¼ 2.5 Hz, 1H),
7.76e7.73 (m, 1H), 7.48 (d, J ¼ 8.5 Hz, 1H), 7.41e7.38 (m, 2H); 13C
NMR (CDCl3, 125 MHz):
d 175.9, 156.0, 154.9, 137.6, 135.2, 129.2,
126.8, 124.3, 123.1, 121.5, 120.0, 118.0, 117.0.
4.3.12. 1-Chloro-9H-xanthen-9-one (2l) [18]
Purification by column chromatography (petroleum ether/
EtOAc, 20/1) as white solid (62.3 mg, 90%). The structure of 2l is the
same as 2i.
4.3.8. 2-(trifluoromethoxy)-9H-xanthen-9-one (2h)
Purification by column chromatography (petroleum ether/
EtOAc, 20/1) as a white solid (62.2 mg, 74%); m.p. 101e103 ꢀC; IR
Please cite this article as: H. Bao et al., Cu(0)/Selectfluor system-catalyzed intramolecular Csp2-H/Csp2-H cross-dehydrogenative coupling (CDC),