R.Y. Huang et al. / Tetrahedron 69 (2013) 4395e4402
4401
8.16e8.15 (m, 2H), 7.82 (t, J¼7.6 Hz, 1H), 7.65 (t, J¼7.5 Hz, 1H), 7.52
(d, J¼8.1 Hz, 1H), 4.04 (s, 3H), 2.63 (s, 3H); 13C NMR (100 MHz,
741 cmꢁ1; HRMS (ESI) [MþH]þ calcd for C23H13F3NO2S: 424.06191;
found: 424.06097.
CDCl3)
d 166.9, 144.6, 137.0, 136.2, 132.3, 131.4, 131.2, 130.9, 130.5,
130.2, 129.5, 129.0, 128.4, 126.2, 125.9, 125.3, 124.4, 124.2, 123.7,
122.4,119.4,117.6,116.9, 52.6, 22.2; IR (NaCl, neat): 2952,1714,1432,
1334, 1300, 1292, 1273, 1250, 1168, 1096, 980, 913, 847, 748, 743,
668 cmꢁ1; HRMS (ESI) [MþH]þ calcd for C25H18NO4S: 428.09565;
found: 428.09666.
4.2.9. Benzo[c]carbazole 3k. Following the general procedure,
a mixture of gem-dibromoolefin 1k (104.7 mg, 0.2 mmol), Pde1
(13.5 mg, 0.02 mmol, 10 mol %), K2CO3 (55.3 mg, 0.4 mmol, 2 equiv)
and CsOPiv (23.4 mg, 0.1 mmol, 50 mol %) in toluene (4 mL) was
heated to 100 ꢀC for 18 h. Subsequent workup and column chro-
matography (hexanes/EtOAc 3:1) afforded 3k as a red-brown solid
(30 mg, 42% yield). Rf¼0.31 (hexanes/EtOAc 7:3). Mp 206e208 ꢀC;
4.2.6. Benzo[c]carbazole 3h. Following the general procedure,
a mixture of gem-dibromoolefin 1h (112.3 mg, 0.2 mmol), Pde1
(13.5 mg, 0.02 mmol, 10 mol %), K2CO3 (55.3 mg, 0.4 mmol, 2 equiv)
and CsOPiv (23.4 mg, 0.1 mmol, 50 mol %) in toluene (4 mL) was
heated to 100 ꢀC for 18 h. Subsequent workup and column chro-
matography (hexanes/EtOAc 7:3) afforded 3h as a light orange
solid (34.9 mg, 44% yield). Rf¼0.31 (hexanes/EtOAc 7:3). Mp
1H NMR (400 MHz, CDCl3)
d
8.70 (d, J¼8.4 Hz, 1H), 8.53 (d, J¼7.5 Hz,
1H), 8.35 (d, J¼8.0 Hz, 1H), 8.26 (s, 1H), 8.07 (d, J¼8.2 Hz, 1H), 7.85
(d, J¼5.1 Hz, 1H), 7.78e7.75 (m, 2H), 7.65e7.56 (m, 3H); 13C NMR
(100 MHz, CDCl3)
d 140.6, 136.5, 134.2, 131.8, 131.4, 130.7, 130.0,
129.2, 128.5, 126.8, 126.7, 125.3, 124.6, 123.7, 123.2, 123.1, 122.8,
118.6,115.0,114.8; IR (NaCl, neat): 1319,1308,1281,1229,1169,1123,
932, 908, 880, 843, 781, 745, 729, 702 cmꢁ1; HRMS (ESI) [MþNH4]þ
calcd for C20H15N2O2S2: 379.05749; found: 379.05777.
240e242 ꢀC; 1H NMR (400 MHz, CDCl3)
8.48 (d, J¼7.3 Hz, 1H), 8.39 (dd, J¼7.4, 1.2 Hz, 1H), 8.37 (s, 1H), 8.18
(d, J¼8.1 Hz, 1H), 8.07 (s, 1H), 7.64e7.56 (m, 2H), 7.47 (d, J¼8.1 Hz,
1H), 7.43e7.38 (m, 2H), 3.97 (s, 3H), 2.58 (s, 3H); 13C NMR
d
8.58 (d, J¼9.0 Hz, 1H),
4.2.10. Benzo[c]carbazole 3l. Following the general procedure,
a mixture of gem-dibromoolefin 1l (93.4 mg, 0.2 mmol), Pde1
(13.5 mg, 0.02 mmol, 10 mol %), K2CO3 (55.3 mg, 0.4 mmol, 2 equiv)
and CsOPiv (23.4 mg, 0.1 mmol, 50 mol %) in toluene (4 mL) was
heated to 100 ꢀC for 18 h. Subsequent workup and column chro-
matography (hexanes/EtOAc 20:1) afforded 3l, which co-eluted
with an impurity. The chromatographed material was triturated
with a minimal amount of hexanes to wash away the impurity and
afford 3l as a yellow solid (33.6 mg, 55% yield). Rf¼0.28 (hexanes/
(100 MHz, CDCl3)
d 157.0, 144.2, 137.5, 133.2, 132.5, 132.4, 131.7,
129.8, 127.4, 126.8, 125.2, 124.9, 124.8, 124.5, 124.2, 122.6, 121.5,
120.8, 120.3, 117.8, 115.6, 108.4, 55.5, 22.1; IR (NaCl, neat): 1600,
1372, 1316, 1243, 1232, 1168, 1144, 1117, 1032, 938, 891, 878, 810,
754, 740, 717, 692 cmꢁ1; HRMS (ESI) [MþH]þ calcd for C24H18NO3S:
400.10047; found: 400.10145.
4.2.7. Benzo[c]carbazole 3i. Following the general procedure,
a mixture of gem-dibromoolefin 1i (107 mg, 0.2 mmol), Pde1
(13.5 mg, 0.02 mmol, 10 mol %), K2CO3 (55.3 mg, 0.4 mmol, 2 equiv)
and CsOPiv (23.4 mg, 0.1 mmol, 50 mol %) in toluene (4 mL) was
heated to 100 ꢀC for 15 h. Subsequent workup and column chro-
matography (hexanes/DCM 1:1) afforded 3i, which co-eluted with
an orange impurity. The chromatographed material was triturated
with hexanes (0.5 mLꢂ3) to wash away the impurity and afford 3n
as an off-white solid (30.3 mg, 41% yield). Rf¼0.22 (hexanes/DCM
EtOAc 15:1). Mp 247e249 ꢀC; 1H NMR (400 MHz, CDCl3)
d 8.57 (d,
J¼8.2 Hz, 1H), 8.48 (d, J¼7.9 Hz, 1H), 8.11 (dd, J¼7.7, 0.7 Hz, 1H), 8.06
(s, 1H), 7.96 (d, J¼8.0 Hz, 1H), 7.62 (ddd, J¼8.2, 7.0, 1.3 Hz, 1H), 7.51
(dd, J¼4.5, 0.8 Hz, 2H), 7.44e7.42 (m, 3H), 7.36 (td, J¼7.4, 1.3 Hz,1H),
7.31 (d, J¼7.5 Hz, 1H), 5.55 (s, 2H); 13C NMR (100 MHz, CDCl3)
d
138.8, 134.8, 130.4, 130.3, 130.1, 129.9, 129.4, 128.5, 128.0, 127.7,
126.9, 124.1, 124.0, 123.3, 123.1, 123.0, 122.2, 120.4, 119.2, 118.6,
113.3,109.3, 45.4; IR (NaCl, neat): 3047,1620,1593, 1588,1531, 1498,
1489, 1471, 1442, 1410, 1386, 1377, 1313, 1226, 1016, 913, 876, 785,
744, 719 cmꢁ1; HRMS (ESI) [MþH]þ calcd for C23H16N: 306.12827;
found: 306.12936.
1:1). Mp 220e223 ꢀC; 1H NMR (400 MHz, CDCl3)
d 8.68 (d,
J¼8.4 Hz, 1H), 8.50 (dd, J¼7.0, 1.7 Hz, 1H), 8.41e8.34 (m, 2H), 8.30
(dd, J¼8.8, 5.2 Hz, 1H), 8.08 (d, J¼8.2 Hz, 1H), 7.92 (dd, J¼9.6,
2.4 Hz, 1H), 7.77 (ddd, J¼8.3, 6.9, 1.3 Hz, 1H), 7.66e7.57 (m, 3H),
7.36 (ddd, J¼8.8, 7.7, 2.4 Hz, 1H); 13C NMR (100 MHz, CDCl3)
d
165.5
4.2.11. Benzo[c]carbazole 3m. Following the general procedure,
a mixture of gem-dibromoolefin 1m (114.5 mg, 0.2 mmol), Pde1
(13.5 mg, 0.02 mmol, 10 mol %), K2CO3 (55.3 mg, 0.4 mmol, 2 equiv)
and CsOPiv (23.4 mg, 0.1 mmol, 50 mol %) in toluene (4 mL) was
heated to 100 ꢀC for 18 h. Subsequent workup and column chro-
matography (hexanes/DCM/EtOAc 85:10:5) afforded 3m as a yel-
low-orange solid (49.1 mg, 60% yield). Rf¼0.25 (hexanes/DCM/
(d, J¼255.4 Hz), 137.3, 135.0 (d, J¼9.2 Hz), 134.2, 131.1 (d, J¼3.1 Hz),
131.0, 130.4, 129.7, 129.0, 127.3, 127.2 (d, J¼9.9 Hz), 127.1, 125.7,
125.2, 123.7, 123.3, 122.8, 120.4, 116.7 (d, J¼2.6 Hz), 116.6 (d,
J¼23.3 Hz), 115.5, 111.8 (d, J¼24.2 Hz); 19F NMR (377 MHz, CDCl3)
d
ꢁ104.13 (td, J¼8.2, 6.0 Hz); IR (NaCl, neat): 3075, 1605, 1586,
1481, 1447, 1337, 1287, 1225, 1173, 1119, 1078, 922, 824, 787, 752,
635 cmꢁ1
;
HRMS (ESI) [MþNH4]þ calcd for C22H16FN2O2S:
EtOAc 85:10:5). Mp 237e238 ꢀC; 1H NMR (400 MHz, CDCl3)
d 8.75
391.09195; found: 391.09119.
(d, J¼8.4 Hz, 1H), 8.46 (d, J¼7.0 Hz, 1H), 8.26e8.22 (m, 2H), 8.12 (d,
J¼8.1 Hz,1H), 7.72 (t, J¼7.5 Hz,1H), 7.61e7.57 (m, 2H), 7.53e7.45 (m,
4H), 7.38 (t, J¼7.7 Hz, 2H), 7.29e7.25 (m, 3H), 7.11e7.09 (m, 1H); 13C
4.2.8. Benzo[c]carbazole 3j. Following the general procedure,
a mixture of gem-dibromoolefin 1j (117 mg, 0.2 mmol), Pde1
(13.5 mg, 0.02 mmol, 10 mol %), K2CO3 (55.3 mg, 0.4 mmol, 2 equiv)
and CsOPiv (23.4 mg, 0.1 mmol, 50 mol %) in toluene (4 mL) was
heated to 100 ꢀC for 18 h. Subsequent workup and column chro-
matography (40% DCM in hexanes) afforded 3j as a golden yellow
solid (44.8 mg, 53% yield). Rf¼0.37 (hexanes/DCM 1:1). Mp
NMR (100 MHz, CDCl3) d 156.3, 143.4, 142.1, 141.2, 140.1, 133.2, 131.9,
130.5, 129.5, 129.2, 129.0 (2C), 128.6, 128.1, 127.7, 127.5, 127.2, 126.5,
125.9, 125.7, 125.3, 124.6, 124.4, 123.8, 121.8, 121.0, 120.3; IR (NaCl,
neat): 3060,1692,1490,1471,1447,1362,1340,1323,1311,1261, 908,
790, 779, 764, 743, 731, 668 cmꢁ1; HRMS (ESI) [MþH]þ calcd for
C29H19N2O: 411.14974; found: 411.14776.
250e252 ꢀC; 1H NMR (400 MHz, CDCl3)
d
8.70 (d, J¼8.4 Hz, 1H),
8.59e8.50 (m, 3H), 8.43 (d, J¼8.3 Hz, 1H), 8.37 (d, J¼7.1 Hz, 1H), 8.15
(d, J¼8.2 Hz, 1H), 7.93 (d, J¼8.2 Hz, 1H), 7.81 (t, J¼7.2 Hz, 1H),
4.2.12. Benzo[e]indole 3n. Following the general procedure, a mix-
ture of gem-dibromoolefin 1n (96.3 mg, 0.2 mmol), Pde1 (13.5 mg,
0.02 mmol, 10 mol %), K2CO3 (55.3 mg, 0.4 mmol, 2 equiv) and
CsOPiv (23.4 mg, 0.1 mmol, 50 mol %) in toluene (4 mL) was heated
to 100 ꢀC for 18 h. Subsequent workup and column chromatogra-
phy (hexanes/DCM 35:65) afforded 3n as a dark yellow solid
(33.7 mg, 53% yield). Rf¼0.28 (hexanes/EtOAc 4:1). Mp 248e250 ꢀC;
7.68e7.57 (m, 3H); 13C NMR (100 MHz, CDC3)
d
137.6 (q, J¼1.2 Hz),
137.3, 135.4 (q, J¼33.2 Hz), 134.0, 132.9, 131.2, 130.5, 129.8, 129.2,
127.4, 127.3, 125.9, 125.6 (q, J¼3.5 Hz), 125.4, 125.3, 123.8, 123.5,
123.3 (q, J¼273.6 Hz), 122.9, 122.2 (q, J¼3.9 Hz), 120.6, 116.4, 115.6;
19F NMR (377 MHz, CDCl3)
1341, 1283, 1221, 1175, 1134, 1088, 1069, 947, 912, 887, 808, 787, 748,
d
ꢁ64.1; IR (NaCl, neat): 3073,1476,1416,
1H NMR (400 MHz, CDCl3)
d
8.38 (s, 1H), 8.24 (d, J¼8.2 Hz, 1H),