Synthesis of polycyclic indole skeletons by a gold(I)-catalyzed cascade reaction

Article abstract of DOI:10.1002/chem.201303539

The conversion of simple, easily available urea-substituted 3-phenylpropargyl alcohols catalyzed by a simple IPr-gold(I) catalyst in a gold(I)-catalyzed cascade reaction composing of a gold-catalyzed nucleophilic addition and a subsequent gold-catalyzed s

Full text of DOI:10.1002/chem.201303539

Supporting Information
ꢀ Copyright Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, 2013
Synthesis of Polycyclic Indole Skeletons by a Gold(I)-Catalyzed
Cascade Reaction
Tao Wang,[a] Shuai Shi,[a] Daniel Pflꢀsterer,[a] Eva Rettenmeier,[a] Matthias Rudolph,[a]
Frank Rominger,[a] and A. Stephen K. Hashmi*[a, b]
chem_201303539_sm_miscellaneous_information.pdf

Synthesis of Polycyclic Indole Skeletons by a Gold(I)-Catalyzed Cascade
Reaction
Tao Wang, Shuai Shi, Daniel Pflästerer, Eva Rettenmeier, Matthias Rudolph, Frank Rominger, A.
Stephen K. Hashmi,*
Ruprecht-Karls-Universität Heidelberg, Organisch-Chemisches Institut, Im Neuenheimer Feld 270,
69120 Heidelberg, Germany, hashmi@hashmi.de

General Information: Chemicals (Aldrich, Fluka, Lancaster, and Merck) were used without
further purification. Dichloromethane and toluene were dried from dried machine. NMR spectra
were recorded on Bruker, ARX300 and AMX250 spectrometers. Chemical shifts were referenced
to residual solvent protons. Signal multiplicity as follows: s (singlet), d (doublet), t (triplet), q
(quartet), m (multiplet), br (broad). MS spectra were recorded on a Finnigan MAT 90 a Varian 711
or a micrOTOF-Q spektometer. IR spectra were recorded on a Bruker Vector 22. Flash
chromatography was performed with Macherey-Nagel silica gel SiO2 (40-63 µm), Thin-layer
chromatography (TLC) was performed on precoated polyester sheets (POLYGRAM SIL
/GUV254), and components were visualized by observation under UV light or by treating the
plates with phosphomolybdic acid hydrate followed by heating.

General procedure for synthesis of substrates 1.
Synthesis of (2-iodophenyl)urea:
For aromatic isocyanates: To a solution of 2-iodo-benzenamin (2 mmol) and isocyanate (2.2 mmol)
in dichloromethane (10 mL) was added 455 mg (4.5 mmol) of triethylamine. The resulting
solution was stirred at room temperature for 12 hours. The precipitate was filtered and washed
with dichloromethane (2mL*3). The solid obtained was air-dried and was used directly for next
step without further purification.
For aliphatic isocyanates: 2-iodoaniline (2.28 mmol) and isocyanate (2.74 mmol) were dissolved
in 1 mL of anhydrous dichloromethane under nitrogen. The solution was stirred at room
temperature under nitrogen for 24 hours. The precipitate was filtered and washed with
dichloromethane (2mL*3). The solid obtained was air-dried and was used directly for next step
without further purification.
Synthesis of substrate 1:
(2-iodophenyl)urea (1 mmol), propargylic alcohol (1.1 mmol) were dissolved in a mixture solvent
of THF (10 mL) and NEt3 (5 mL) under nitrogen. Pd(PPh3)4 (14 mg, 0.02 mmol) and CuI (7.6 mg,
0.04 mmol) were added and the reaction mixture was stirred at room temperature for 2 hours. The
solvent was removed and the crude product was purified via column chromatography on silica gel
(hexane / ethyl acetate 6:1 to 3:1) to yield substrate1 in good to excellent yields.
1-(2-(3-hydroxy-3-phenylprop-1-yn-1-yl)phenyl)-3-phenylurea (1a).

o
1
Yield: 88%, white solid, m.p. 167-168 C; H NMR [300 MHz, (CD3)CO]: δ = 8.71 (sbr, 1 H),
8.26 (d, 1 H, J = 8.3 Hz), 8.00 (sbr, 1 H), 7.64 (d, 2 H, J = 7.1 Hz), 7.54 (d, 2 H, J = 7.7 Hz),
7.41-7.25 (m, 7 H), 7.02-6.97 (m, 2 H), 5.75 (d, 1 H, J = 5.7 Hz), 5.25 (d, 1 H, J = 5.7 Hz); 13C
NMR [75 MHz, (CD3)CO]: δ = 153.5, 143.0, 142.0, 141.0, 133.2, 130.6, 130.0, 129.6, 129.1,
128.0, 123.7, 123.2, 120.7, 120.1, 112.7, 98.1, 82.1, 65.4 ppm; IR (ATR): ṽ = 3275, 3059, 3036,
1950, 1742, 1645, 1598, 1578, 1547, 1497, 1478, 1446, 1295, 1247, 1216, 1185, 1159, 1112, 1078,
1024, 1001, 966, 919, 899, 822, 752, 742, 714, 693, 660, 633 cm-1; HRMS (ESI): calculated for
C22H18N2O2Na [M+Na]+ : 365.1260, found 365.1263.
1-(2-(3-hydroxy-3-phenylprop-1-yn-1-yl)phenyl)-3-(p-tolyl)urea (1b).
o
1
Yield: 85%, yellow solid, m.p. 171-172 C; H NMR [500 MHz, (CD3)CO]: δ = 8.55 (sbr, 1 H),
8.27 (d, 1 H, J = 8.3 Hz), 7.93 (sbr, 1 H), 7.63 (d, 2 H, J = 7.4 Hz), 7.41-7.37 (m, 5 H), 7.35-7.30
(m, 2 H), 7.09 (d, 2 H, J = 8.3 Hz), 6.98 (td, 1 H, J1 = 7.6 Hz, J2 = 1.0 Hz), 5.74 (d, 1 H, J = 5.9
Hz), 5.24 (d, 1 H, J = 5.9 Hz), 2.26 (s, 3 H); 13C NMR [125 MHz, (CD3)CO]: δ = 153.2, 142.6,
141.7, 138.0, 132.9, 132.7, 130.3, 130.2, 129.3, 128.8, 127.6, 122.7, 120.2, 120.0, 112.2, 97.7,
81.8, 65.0, 20.8 ppm; IR (ATR): ṽ = 3651, 3297, 3031, 1644, 1603, 1577, 1547, 1511, 1492, 1476,
1448, 1406, 1293, 1249, 1216, 1189, 1110, 1079, 1023, 966, 905, 818, 790, 748, 708, 695, 638,
613 cm-1; HRMS (ESI): calculated for C23H20N2O2Na [M+Na]+ : 379.1417, found 379.1420.
1-(2-(3-hydroxy-3-phenylprop-1-yn-1-yl)phenyl)-3-(4-methoxyphenyl)urea (1c).
o
1
Yield: 75%, yellow solid, m.p. 175-176 C; H NMR [400 MHz, (CD3)CO]: δ = 8.59 (sbr, 1 H),
8.27 (d, 1 H, J = 8.4 Hz), 7.93 (sbr, 1 H), 7.64-7.62 (m, 2 H), 7.46-7.29 (m, 7 H), 6.97 (td, 1 H, J1
= 7.6 Hz, J2 = 1.2 Hz), 6.88-6.84 (m, 2 H), 5.72 (d, 1 H, J = 5.5 Hz), 5.28 (d, 1 H, J = 5.5 Hz),
3.75 (s, 3 H); 13C NMR [100 MHz, (CD3)CO]: δ = 156.5, 153.4, 142.7, 142.0, 133.6, 132.8, 130.2,
129.3, 128.7, 127.7, 122.6, 121.9, 120.1, 114.9, 112.1, 97.9, 81.7, 65.0, 55.7 ppm; IR (ATR): ṽ =

3299, 3063, 2938, 2838, 1643, 1605, 1578, 1547, 1508, 1475, 1450, 1411, 1301, 1244, 1180, 1168,
1108, 1079, 1023, 960, 911, 828, 793, 756, 695, 636, 610 cm-1; HRMS (ESI): calculated for
C23H20N2O3Na [M+Na]+ : 395.1366, found 395.1370.
1-(4-chlorophenyl)-3-(2-(3-hydroxy-3-phenylprop-1-yn-1-yl)phenyl)urea (1d).
o
1
Yield: 80%, white solid, m.p. 188-189 C; H NMR [500 MHz, (CD3)CO]: δ = 8.79 (sbr, 1 H),
8.23 (d, 1 H, J = 8.4 Hz). 7.98 (sbr, 1 H), 7.63 (d, 2 H, J = 7.3 Hz), 7.55 (d, 2 H, J = 8.8 Hz),
7.43-7.28 (m, 7 H), 7.02 (t, 1 H, J = 7.6 Hz), 5.74 (d, 1 H, J = 5.9 Hz), 5.20 (d, 1 H, J = 5.9 Hz);
13C NMR [125 MHz, (CD3)CO]: δ = 152.9, 142.7, 141.5, 139.7, 133.0, 130.3, 129.6, 129.3, 128.8,
127.7, 123.1, 121.0, 120.4, 112.5, 97.9, 81.7, 65.1 ppm; IR (ATR): ṽ = 3325, 3059, 2926, 2850,
1946, 1810, 1683, 1631, 1598, 1577, 1549, 1497, 1446, 1395, 1303, 1250, 1216, 1175, 1114, 1085,
1048, 1029, 1002, 986, 947, 917, 894, 824, 776, 748, 723, 692, 642, 607 cm-1; HRMS (ESI):
calculated for C22H17ClN2O2Na [M+Na]+ : 399.0871, found 399.0872.
1-(2-(3-hydroxy-3-phenylprop-1-yn-1-yl)phenyl)-3-(4-(trifluoromethyl)phenyl)urea (1e).
o
1
Yield: 70%, white solid, m.p. 189-190 C; H NMR [300 MHz, (CD3)CO]: δ = 9.12 (sbr, 1 H),
8.24 (d, 1 H, J = 8.3 Hz), 8.10 (sbr, 1 H), 7.75 (d, 2 H, J = 8.5 Hz), 7.65-7.60 (m, 4 H), 7.44-7.28
(m, 5 H), 7.03 (t, 1 H, J = 7.5 Hz), 5.77 (d, 1 H, J = 5.0 Hz), 5.30 (d, 1 H, J = 5.0 Hz). 13C NMR
[75 MHz, (CD3)CO]: δ = 253.3, 144.8, 143.0, 141.7, 133.3, 130.7, 129.7, 129.2, 128.0, 127.3 (q,
JF-C = 3.9 Hz), 123.7, 121.0, 119.5, 113.2, 98.2, 82.1, 65.5 ppm; 19F NMR [282 MHz, (CD3)CO]:
-62.2 ppm; IR (ATR): ṽ = 3292, 3062, 1914, 1649, 1602, 1577, 1542, 1492, 1477, 1449, 1410,
1328, 1300, 1251, 1224, 1183, 1155, 1108, 1070, 1047, 1025, 1017, 968, 905, 867, 845, 798, 747,
711, 694, 639 cm-1; HRMS (ESI): calculated for C23H16F3N2O2 [M-H]- : 409.1169, found
409.1182.
1-butyl-3-(2-(3-hydroxy-3-phenylprop-1-yn-1-yl)phenyl)urea (1f).

Yield: 83%, yellow oil; 1H NMR (300 MHz, CD2Cl2): δ = 7.96 (d, 1 H, J = 8.3 Hz), 7.55 (d, 2 H,
J = 7.5 Hz), 7.38-7.19 (m, 6 H), 6.91 (t, 1 H, J = 7.6 Hz), 5.68 (s, 1 H), 5.34 (s, 1 H), 4.74 (s, 1 H),
3.05-2.99 (m, 2 H), 1.33-1.16 (m, 4 H), 0.82 (t, 3 H, J = 7.2 Hz); 13C NMR (75 MHz, CD2Cl2): δ =
156.3, 141.4, 141.1, 132.2, 130.3, 129.2, 128.9, 127.2, 122.7, 120.0, 112.2, 96.5, 82.7, 65.3, 40.6,
32.6, 20.6, 14.1 ppm; IR (ATR): ṽ = 3330, 2958, 2931, 2871, 2220, 1652, 1606, 1549, 1493, 1447,
1379, 1302, 1249, 1219, 1159, 1097, 1043, 1016, 964, 917, 821, 755, 698, 641, 614 cm-1; HRMS
(ESI): calculated for C20H22N2O2Na [M+Na]+ : 345.1574, found 345.1579.
1-(2-(3-hydroxy-3-(4-methoxyphenyl)prop-1-yn-1-yl)phenyl)-3-phenylurea (1g).
o
1
Yield: 83%, yellow solid, m.p. 134-135 C; H NMR [300 MHz, (CD3)CO]: δ = 8.69 (sbr, 1 H),
8.26 (d, 1 H, J = 8.4 Hz), 7.96 (sbr, 1 H), 7.56-7.51 (m, 4 H), 7.41-7.25 (m, 4 H), 7.02-6.91 (m, 4
H), 5.69 (d, 1 H, J = 5.7 Hz), 5.13 (d, 1 H, J = 5.7 Hz), 3.78 (s, 3 H); 13C NMR [125 MHz,
(CD3)CO]: δ = 160.9, 153.5, 142.1, 141.1, 135.2, 133.2, 130.6, 130.1, 129.4, 123.7, 123.2, 120.7,
120.1, 115.0, 112.9, 98.4, 82.0, 65.1, 56.0 ppm; IR (ATR): ṽ = 3566, 3295, 3063, 2958, 2932,
2830, 2223, 1946, 1868, 1771, 1649, 1601, 1579, 1544, 1509, 1478, 1464, 1446, 1379, 1301, 1245,
1174, 1109, 1079, 1030, 1015, 986, 965, 898, 871, 826, 803, 752, 716, 692, 681, 646, 608 cm-1;
HRMS (ESI): calculated for C23H19N2O3 [M-H]- : 371.1401, found 371.1411.
1-(2-(3-hydroxy-3-(4-(trifluoromethyl)phenyl)prop-1-yn-1-yl)phenyl)-3-phenylurea (1h).
o
1
Yield: 73%, white solid, m.p. 200-201 C; H NMR [300 MHz, (CD3)CO]: δ = 8.64 (sbr, 1 H),
8.24 (d, 1 H, J = 8.4 Hz), 7.97 (sbr, 1 H), 7.87 (d, 2 H, J = 8.2 Hz), 7.73 (d, 2 H, J = 8.2 Hz), 7.52
(d, 2 H, J = 8.2 Hz),7.42-7.25 (m, 4 H), 7.00 (t, 2 H, J = 7.5 Hz), 5.88 (d, 1 H, J = 5.9 Hz), 5.52 (d,

1 H, J = 5.9 Hz). 13C NMR [75 MHz, (CD3)CO]: δ = 153.5, 147.5, 142.1, 141.0, 133.4, 130.8,
130.1, 128.6, 126.6 (q, JF-C= 3.9 Hz), 123.7, 123.3, 120.9, 120.1, 112.6, 97.2, 82.7, 64.8 ppm; 19F
NMR [282 MHz, (CD3)CO]: -62.9 ppm; IR (ATR): ṽ = 3302, 1641, 1619, 1598, 1579, 1551, 1496,
1479, 1447, 1414, 1391, 1325, 1304, 1248, 1223, 1164, 1111, 1068, 1051, 1016, 975, 914, 897,
849, 826, 796, 751, 718, 692, 646, 633 cm-1; HRMS (ESI): calculated for C23H16F3N2O2 [M-H]- :
409.1169, found 409.1182.
1-(2-(3-hydroxy-3-phenylprop-1-yn-1-yl)-4-methylphenyl)-3-phenylurea (1i).
o
1
Yield: 76%, white solid, m.p. 178-179 C; H NMR [300 MHz, (CD3)CO]: δ = 8.64 (sbr, 1 H),
8.12 (d, 1 H, J = 8.5 Hz), 7.89 (sbr, 1 H), 7.63 (d, 2 H, J = 7.6 Hz), 7.52 (d, 2 H, J = 8.3 Hz),
7.41-7.15 (m, 7 H), 6.99 (t, 1 H, J = 7.4 Hz), 5.73 (d, 1 H, J = 5.9 Hz), 5.23 (d, 1 H, J = 5.9 Hz),
2.26 (s, 3 H); 13C NMR [125 MHz, (CD3)CO]: δ = 153.2, 142.7, 140.9, 139.3, 133.0, 132.3, 131.0,
129.7, 129.3, 128.8, 127.7, 123.2, 120.5, 119.6, 112.4, 97.3, 82.0, 65.1, 20.5 ppm; IR (ATR): ṽ =
3289, 3026, 1637, 1586, 1554, 1497, 1443, 1294, 1254, 1220, 1186, 1131, 1078, 1042, 1028, 1005,
897, 809, 778, 738, 714, 692, 640, 614 cm-1; HRMS (ESI): calculated for C23H19N2O2 [M-H]- :
355.1452, found 355.1462.
1-(4-chloro-2-(3-hydroxy-3-phenylprop-1-yn-1-yl)phenyl)-3-phenylurea (1j).
OH
Ph
Cl
O
Ph
N
N
H
H
o
1
Yield: 77%, white solid, m.p. 203-204 C; H NMR [500 MHz, (CD3)CO]: δ = 8.70 (sbr, 1 H),
8.28 (d, 1 H, J = 9.0 Hz), 8.03 (sbr, 1 H), 7.63 (d, 2 H, J = 7.5 Hz), 7.52 (d, 2 H, J = 7.8 Hz),
7.42-7.27 (m, 7 H); 7.02 (t, 1 H, J = 7.4 Hz), 5.74 (d, 1 H, J = 5.4 Hz), 5.27 (d, 1 H, J = 5.4 Hz);
13C NMR [125 MHz, (CD3)CO]: δ = 152.9, 142.4, 140.6, 140.5, 132.1, 130.2, 129.8, 129.4, 128.9,
127.7, 127.0, 123.5, 121.7, 119.7, 114.0, 99.0, 80.4, 65.0 ppm; IR (ATR): ṽ = 3291, 3060, 3028,
1942, 1894, 1636, 1598, 1576, 1544, 1493, 1476, 1445, 1400, 1291, 1247, 1207, 1184, 1158, 1124,
1088, 1037, 1024, 980, 913, 897, 879, 836, 803, 773, 752, 730, 707, 691, 638 cm-1; HRMS (ESI):

calculated for C22H17ClN2O2Na [M+Na]+ : 399.0871, found 399.0874.
1-(2-(3-hydroxy-3-methylbut-1-yn-1-yl)phenyl)-3-phenylurea (1k).
Yield: 95%, white solid, m.p. 126-127 oC; 1H NMR (300 MHz, CD2Cl2): δ = 7.97 (d, 1 H, J = 8.2
Hz), 7.69 (sbr, 1 H), 7.52 (sbr, 1 H), 7.37-7.34 (m, 2 H), 7.30-7.19 (m, 4 H), 7.04 (t, 1 H, J = 7.3
Hz), 6.94 (td, 1 H, J1 = 7.6 Hz, J2 = 1.0 Hz), 3.86 (sbr, 1 H), 1.55 (s, 6 H); 13C NMR (75 MHz,
CD2Cl2): δ = 153.9, 140.0, 138.8, 132.3, 129.8, 129.6, 124.4, 123.5, 121.4, 121.0, 113.4, 100.9,
78.5, 66.5, 31.7 ppm; IR (ATR): ṽ = 3323, 2985, 2934, 1664, 1601, 1582, 1525, 1499, 1444, 1363,
1302, 1254, 1220, 1157, 1112, 1045, 963, 907, 823, 749, 692, 634 cm-1; HRMS (ESI):
calculated for C18H18N2O2Na [M+Na]+ : 317.1261, found 317.1265.
1-(2-(3-hydroxy-3-phenylbut-1-yn-1-yl)phenyl)-3-phenylurea (1l).
o
1
Yield: 70%, yellow solid, m.p. 175-176 C; H NMR (500 MHz, CD3OD): δ = 8.01 (d, 1 H, J =
8.3 Hz), 7.73-7.71 (m, 2 H), 7.46-7.42 (m, 3 H), 7.37-7.25 (m, 6 H), 7.06-7.01 (m, 2 H), 1.86 (s, 3
H); 13C NMR (125 MHz, CD3OD): δ = 155.1, 147.2, 141.3, 140.5, 133.3, 130.5, 130.1, 129.5,
128.8, 126.3, 124.2, 124.0, 121.7, 120.6, 114.2, 100.4, 81.2, 71.3, 34.0 ppm; IR (KBr): ṽ = 3325,
1655, 1599, 1580, 1525, 1498, 1445, 1366, 1302, 1253, 1221, 1159, 1141, 1088, 1048, 1028, 940,
893, 749, 693, 606 cm-1; HRMS (ESI): calculated for C23H20N2O2Na [M+Na]+ : 379.1417, found
379.1420.
General Procedure for Gold(I)-catalyzed Cascade Reactions.
Urea1 (0.4 mmol) was added to a suspension of IPrAuCl (0.02 mmol, 12.4 mg) and AgNTf2 (0.02
mmol, 7.8 mg) in a mixed solvent (2.2 ml, Toluene/CH3CN = 10:1), the resulting suspension was
stirred at 110 oC for 12 h. After that the solution was removed by evaporation and the residue was
purified by column chromatography on silica gel (petrol ether/EtOAc = 10:1) to afford the desired
product.

1,2-diphenyl-1H-imidazo[1,5-a]indol-3(2H)-one (4a).
Yield: 71%, white solid, m.p. 167-168 oC; 1H NMR (300 MHz, CD2Cl2): δ = 8.09 (d, 1 H, J = 7.9
Hz), 7.60-7.53 (m, 3 H), 7.39-7.24 (m, 9 H), 7.17-7.12 (m, 1 H), 6.28 (s, 1 H), 6.27 (s, 1 H); 13C
NMR (75 MHz, CD2Cl2): δ = 150.8, 139.1, 137.9, 137.8, 134.0, 131.1, 129.7, 129.5, 129.3, 127.6,
125.6, 124.0, 123.5, 123.0, 121.8, 113.2, 98.4, 61.4 ppm; IR (ATR): ṽ = 3060, 2924, 2850, 1725,
1599, 1501, 1491, 1479, 1450, 1405, 1371, 1334, 1306, 1289, 1252, 1231, 1172, 1158, 1144, 1126,
1108, 1075, 1057, 1028, 981, 937, 911, 893, 856, 845, 832, 791, 781, 767, 747, 707, 692, 658, 641,
616 cm-1; HRMS (ESI): calculated for C22H16N2ONa [M+Na]+ : 347.1155, found 347.1159.
4a (2% ee), Enantiomeric excess was determined by HPLC with a Chiralpak IB column (85:15
hexane: 2-propanol, 1 mL/min, 280 nm); minor enantiomer tr = 7.6 min, major enantiomer tr = 8.0
min; (2% ee).
1-phenyl-2-(p-tolyl)-1H-imidazo[1,5-a]indol-3(2H)-one (4b).
o
1
Yield: 53%, yellow solid, m.p. 183-184 C; H NMR (300 MHz, CD2Cl2): δ = 8.09 (d, 1 H, J =
8.1 Hz), 7.58 (d, 1 H, J = 7.8 Hz), 7.41-7.24 (m, 9 H), 7.15 (d, 2 H, J = 8.3 Hz), 6.27 (s, 1 H), 6.21
(s, 1 H), 2.30 (s, 3 H); 13C NMR (75 MHz, CD2Cl2): δ = 150.9, 139.3, 137.9, 135.7, 135.0, 133.9,
131.1, 130.1, 129.7, 129.3, 127.7, 123.9, 123.4, 122.9, 121.7, 113.1, 98.4, 61.6, 21.1 ppm; IR
(ATR): ṽ = 3030, 2919, 1721, 1613, 1591, 1516, 1493, 1479, 1452, 1406, 1368, 1335, 1316, 1288,
1248, 1231, 1172, 1157, 1142, 1127, 1106, 1077, 1058, 1032, 1015, 982, 965, 927, 911, 850, 832,
796, 783, 763, 738, 711, 694, 674, 653, 638, 615 cm-1; HRMS (ESI): calculated for C23H18N2ONa
[M+Na]+ : 361.1311, found 361.1316.
2-(4-chlorophenyl)-1-phenyl-1H-imidazo[1,5-a]indol-3(2H)-one (4d).

Yield: 70%, white solid, m.p. 164-165 oC; 1H NMR (300 MHz, CD2Cl2): δ = 8.08 (d, 1 H, J = 8.0
Hz), 7.59-7.50 (m, 3 H), 7.38-7.25 (m, 9 H), 6.28 (s, 1 H), 6.21 (s, 1 H); 13C NMR (75 MHz,
CD2Cl2): δ = 150.6, 138.8, 137.5, 136.6, 134.0, 131.1, 130.6, 129.8, 129.6, 129.5, 127.5, 124.1,
123.6, 123.5, 121.8, 113.2, 98.7, 61.4 ppm; IR (ATR): ṽ = 3566, 3067, 3027, 2925, 1944, 1868,
1724, 1599, 1541, 1495, 1478, 1449, 1417, 1401, 1368, 1335, 1285, 1257, 1228, 1201, 1177, 1156,
1143, 1127, 1115, 1096, 1078, 1058, 1029, 1012, 982, 934, 909, 847, 818, 792, 781, 770, 738, 720,
707, 693, 669, 648, 628, 616 cm-1; HRMS (ESI): calculated for C22H16ClN2O [M+H]+ : 359.0946,
found 359.0948.
1-phenyl-2-(4-(trifluoromethyl)phenyl)-1H-imidazo[1,5-a]indol-3(2H)-one (4e).
Yield: 75%, white solid, m.p. 165-166 oC; 1H NMR (300 MHz, CD2Cl2): δ = 8.09 (d, 1 H, J = 8.0
Hz), 7.78 (d, 2 H, J = 8.5 Hz), 7.61-7.56 (m, 3 H), 7.39-7.25 (m, 7 H), 6.29 (s, 2 H); 13C NMR
(125 MHz, CD2Cl2): δ = 150.5, 141.3, 138.5, 137.3, 134.0, 131.1, 129.9, 129.5, 127.1, 127.0 (q,
JF-C = 261 Hz), 126.7 (q, JF-C = 3.9 Hz), 124.2, 123.8, 121.9, 120.9, 113.2, 98.8, 61.0 ppm; 19F
NMR (282 MHz, CD2Cl2): δ = -62.5 ppm; IR (ATR): ṽ = 2927, 1738, 1615, 1522, 1480, 1452,
1426, 1405, 1366, 1320, 1302, 1257, 1167, 1113, 1071, 1056, 1013, 982, 839, 795, 779, 744, 707,
694, 662, 649, 633 cm-1; HRMS (ESI): calculated for C23H15F3N2ONa [M+Na]+ : 415.1029, found
415.1031.
2-butyl-1-phenyl-1H-imidazo[1,5-a]indol-3(2H)-one (4f).
Yield: 41%, yellow solid, m.p. 74-75 oC; 1H NMR (500 MHz, CD2Cl2): δ = 8.00 (d, 1 H, J = 8.1
Hz), 7.55 (d, 1 H, J = 7.8 Hz), 7.41-7.38 (m, 3 H), 7.32-7.27 (m, 3 H), 7.23-7.19 (m, 1 H), 6.21 (s,

1 H), 5.61 (s, 1 H); 3.72-3.65 (m, 1 H), 2.95-2.89 (m, 1 H), 1.55-1.48 (m, 2 H), 1.37-1.27 (m, 2 H),
0.90 (t, 3 H, J = 7.4 Hz); 13C NMR (125 MHz, CD2Cl2): δ = 152.3, 140.5, 137.6, 133.7, 131.0,
129.7, 129.5, 128.3, 123.6, 122.8, 121.6, 112.8, 97.9, 60.2, 41.4, 30.4, 20.4, 14.0 ppm; IR (ATR):
ṽ = 3431, 3086, 3061, 3032, 2959, 2929, 2872, 2316, 1955, 1868, 1810, 1734, 1613, 1584, 1520,
1493, 1478, 1453, 1412, 1391, 1351, 1312, 1267, 1216, 1184, 1156, 1114, 1101, 1085, 1071, 1027,
1002, 970, 933, 912, 859, 831, 794, 779, 746, 707, 695, 670, 655, 638, 617 cm-1; HRMS (ESI):
calculated for C20H20N2ONa [M+Na]+ : 327.1468, found 327.1469.
1-(4-methoxyphenyl)-2-phenyl-1H-imidazo[1,5-a]indol-3(2H)-one (4g).
o
1
Yield: 40%, yellow solid, m.p. 155-156 C; H NMR (500 MHz, CD2Cl2): δ = 8.07 (d, 1 H, J =
8.1 Hz), 7.58 (d, 1 H, J = 7.9 Hz), 7.52-7.50 (m, 2 H), 7.36-7.33 (m, 3 H), 7.28-7.22 (m, 3 H),
7.15 (t, 1 H, J = 7.4 Hz), 6.85-6.82 (m, 2 H), 6.27 (s, 1 H), 6.21 (s, 1 H), 3.74 (s, 3 H); 13C NMR
(125 MHz, CD2Cl2): δ = 160.5, 150.7, 139.5, 137.7, 134.0, 131.1, 129.49, 129.48, 129.0, 125.6,
123.9, 123.4, 123.0, 121.7, 115.0, 113.1, 98.3, 61.1, 55.8 ppm; IR (ATR): ṽ = 3061, 2931, 2836,
1732, 1611, 1599, 1586, 1511, 1478, 1451, 1422, 1403, 1365, 1329, 1304, 1248, 1171, 1144, 1107,
1030, 981, 934, 897, 840, 800, 782, 741, 697, 652, 636, 623 cm-1; HRMS (ESI): calculated for
C23H18N2O2Na [M+Na]+ : 377.1261, found 377.1266.
2-phenyl-1-(4-(trifluoromethyl)phenyl)-1H-imidazo[1,5-a]indol-3(2H)-one (4h).
Yield: 36%, white solid, m.p. 145-146 oC; 1H NMR (500 MHz, CD2Cl2): δ = 8.07 (d, 1 H, J = 8.0
Hz), 7.61-7.57 (m, 3 H), 7.53-7.49 (m, 4 H), 7.37-7.33 (m, 3 H), 7.29-7.25 (m, 1 H), 7.16 (t, 1 H, J
= 7.4 Hz), 6.35 (s, 1 H), 6.31 (s, 1 H); 13C NMR (125 MHz, CD2Cl2): δ = 150.6, 142.0, 138.0,
137.5, 133.8, 131.1, 129.7, 128.0, 126.7 (q, JF-C = 3.9 Hz), 125.8, 124.2, 123.6, 122.4, 121.9,
113.2, 98.9, 60.8 ppm; 19F NMR (282 MHz, CD2Cl2): -63.0 ppm; IR (ATR): ṽ = 3062, 2926, 2851,

1729, 1619, 1598, 1502, 1479, 1451, 1419, 1403, 1366, 1322, 1254, 1229, 1166, 1124, 1066, 1017,
981, 935, 895, 861, 844, 797, 783, 744, 705, 688, 667, 648, 608 cm-1; HRMS (ESI): calculated for
C23H15F3N2ONa [M+Na]+ : 415.1029, found 415.1033.
7-chloro-1,2-diphenyl-1H-imidazo[1,5-a]indol-3(2H)-one (4j).
o
1
Yield: 45%, yellow solid, m.p. 169-170 C; H NMR (500 MHz, CD2Cl2): δ = 8.01 (d, 1 H, J =
8.6 Hz), 7.56-7.51 (m, 3 H), 7.36-7.30 (m, 8 H), 7.15 (t, 1 H, J = 7.4 Hz), 6.26 (s, 1 H), 6.25 (s, 1
H); 13C NMR (125 MHz, CD2Cl2): δ = 150.4, 140.5, 137.5, 137.3, 135.0, 129.8, 129.6, 129.5,
129.4, 128.9, 127.5, 125.8, 124.2, 122.7, 121.3, 114.1, 98.0, 61.4 ppm; IR (ATR): ṽ = 3066, 3035,
2925, 2851, 1953, 1881, 1733, 1598, 1578, 1503, 1455, 1430, 1404, 1363, 1290, 1266, 1252, 1222,
1200, 1185, 1175, 1163, 1124, 1113, 1079, 1061, 1050, 1028, 980, 942, 913, 898, 891, 870, 852,
824, 813, 796, 774, 747, 737, 718, 699, 693, 669, 646, 617 cm-1; HRMS (ESI): calculated for
C44H30Cl2N4O2Na [2M+Na]+ : 739.1638, found 739.1643.
1,1-dimethyl-2-phenyl-1H-imidazo[1,5-a]indol-3(2H)-one (4k).
N
N
Ph
O
Yield: 77%, white solid, m.p. 192-193 oC; 1H NMR (300 MHz, CD2Cl2): δ = 7.98 (d, 1 H, J = 7.4
Hz), 7.64 (d, 1 H, J = 7.4 Hz), 7.55-7.47 (m, 3 H), 7.38-7.24 (m, 4 H), 6.41 (s, 1 H), 1.61 (s, 6 H);
13C NMR (75 MHz, CD2Cl2): δ = 151.3, 146.0, 135.4, 133.9, 131.1, 130.4, 130.0, 129.0, 123.6,
123.1, 121.6, 113.0, 95.8, 61.8, 27.8 ppm; IR (ATR): ṽ = 3109, 3058, 2976, 2930, 1730, 1598,
1583, 1494, 1478, 1450, 1427, 1405, 1379, 1338, 1300, 1284, 1225, 1198, 1186, 1172, 1144, 1108,
1089, 1071, 1030, 1006, 971, 931, 907, 844, 837, 807, 749, 702, 680, 654 cm-1; HRMS (ESI):
calculated for C18H16N2ONa [M+Na]+ : 299.1155, found 299.1159.
1-methyl-1,2-diphenyl-1H-imidazo[1,5-a]indol-3(2H)-one (4l).

o
1
Yield: 62%, yellow solid, m.p. 148-149 C; H NMR (500 MHz, CD2Cl2): δ = 8.06 (d, 1 H, J =
8.1 Hz), 7.60 (d, 1 H, J = 7.8 Hz), 7.36-7.25 (m, 10 H), 7.03-7.01 (m, 2 H), 6.25 (s, 1 H), 2.01 (s,
3H); 13C NMR (125 MHz, CD2Cl2): δ = 151.2, 145.6, 141.7, 135.9, 134.0, 131.0, 129.5, 129.3,
129.0, 128.3, 128.0, 127.1, 123.8, 123.3, 121.8, 113.1, 96.9, 66.3, 24.3 ppm; δ =IR (ATR): ṽ =
3113, 3059, 2970, 1732, 1613, 1597, 1585, 1492, 1477, 1450, 1402, 1364, 1339, 1302, 1219, 1203,
1171, 1140, 1103, 1073, 1046, 1026, 1002, 968, 950, 909, 837, 818, 794, 783, 759, 736, 709, 697,
674, 656, 640, 616 cm-1; HRMS (ESI): calculated for C23H18N2ONa [M+Na]+ : 361.1311, found
361.1314.
2-(hydroxy(phenyl)methyl)-N-phenyl-1H-indole-1-carboxamide (2a).
o
1
Yield: 50%, yellow solid, m.p. 165-166 C; H NMR (300 MHz, CD2Cl2): δ = 9.34 (sbr, 1 H),
8.01 (d, 1 H, J = 8.3 Hz), 7.51-7.45 (m, 3 H), 7.37-7.29 (m, 8 H), 7.24-7.12 (m, 2 H), 6.27 (s, 1 H),
6.16 (d, 1 H, J = 2.9 Hz), 4.53 (d, 1 H, J = 3.7 Hz); 13C NMR (75 MHz, CD2Cl2): δ = 150.7, 140.6,
140.5, 137.9, 137.8, 129.6, 128.8, 128.6, 128.4, 126.7, 125.13, 125.10, 123.0, 121.7, 120.6, 114.7,
110.5, 70.2 ppm; δ =IR (ATR): ṽ = 3257, 3142, 3026, 2926, 1943, 1679, 1632, 1599, 1567, 1498,
1446, 1414, 1355, 1325, 1300, 1270, 1236, 1214, 1203, 1157, 1118, 1093, 1074, 1006, 950, 878,
856, 818, 796, 780, 752, 742, 717, 690, 671, 618 cm-1; HRMS (ESI): calculated for C22H18N2O2Na
[M+Na]+ : 365.1261, found 365.1261.
2a (>99% ee): Enantiomeric excess was determined by HPLC with a Chiralpak IB column (90:10
hexane: 2-propanol, 1 mL/min, 250 nm); major enantiomer tr = 12.9 min, minor enantiomer tr =
16.2 min, (>99% ee).
2-(hydroxy(phenyl)methyl)-N-(4-methoxyphenyl)-1H-indole-1-carboxamide (2c).
o
1
Yield: 70%, yellow solid, m.p. 139-140 C; H NMR (300 MHz, CD2Cl2): δ = 9.15 (sbr, 1 H),

7.98 (d, 1 H, J = 8.3 Hz), 7.50 (d, 1 H, J = 7.7 Hz), 7.35-7.18 (m, 9 H), 6.85 (d, 2 H, J = 8.8 Hz),
6.26 (s, 1 H), 6.13 (d, 1 H, J = 3.8 Hz), 4.69 (sbr, 1 H), 3.78 (s, 3 H); 13C NMR (75 MHz, CD2Cl2):
δ = 157.4, 151.0, 140.7, 140.6, 137.7, 130.7, 128.8, 128.6, 128.3, 126.7, 125.0, 122.9, 122.7,
121.7, 114.7, 114.6, 110.2, 70.1, 56.0 ppm; IR (ATR): ṽ = 3272, 3140, 3065, 2928, 2850, 1869,
1680, 1611, 1557, 1512, 1452, 1416, 1319, 1301, 1240, 1178, 1158, 1120, 1088, 1033, 951, 920,
888, 825, 784, 752, 716, 701, 671, 636, 622 cm-1; HRMS (ESI): calculated for C23H19N2O3
[M-H]- : 371.1401, found 371.1410.
2-(2-hydroxypropan-2-yl)-N-phenyl-1H-indole-1-carboxamide (2k).
o
1
Yield: 50%, yellow solid, m.p. 156-157 C; H NMR (300 MHz, CD2Cl2): δ = 10.01 (sbr, 1 H),
7.96 (d, 1 H, J = 8.3 Hz), 7.63 (d, 2 H, J = 8.3 Hz), 7.53 (d, 1 H, J = 7.8 Hz), 7.39 (t, 1 H, J = 7.8
Hz), 7.30-7.16 (m, 3 H), 6.57 (s, 1 H), 4.27 (s, 1 H), 1.73 (s, 6 H); 13C NMR (75 MHz, CD2Cl2): δ
= 151.6, 144.2, 138.4, 138.2, 129.7, 128.2, 125.2, 124.8, 122.8, 121.5, 120.5, 114.5, 106.4, 70.0,
29.9 ppm; IR (ATR): ṽ = 3281, 2985, 1670, 1636, 1601, 1569, 1501, 1491, 1445, 1391, 1358,
1332, 1295, 1239, 1207, 1189, 1159, 1147, 1132, 1108, 1063, 1018, 958, 918, 886, 847, 811, 755,
733, 691, 680, 638 cm-1; HRMS (ESI): calculated for C18H18N2O2Na [M+Na]+ : 317.1261, found
317.1263.
N-phenyl-2-(prop-1-en-2-yl)-1H-indole-1-carboxamide (3k).
o
1
Yield: 35%, white solid, m.p. 85-86 C; H NMR (300 MHz, CD2Cl2): δ = 8.08 (d, 1 H, J = 8.2
Hz), 7.62-7.51 (m, 4 H), 7.42-4.16 (m, 5 H), 6.63 (s, 1 H), 5.50 (s, 1 H), 5.43 (s, 1 H), 2.16 (s, 3
H); 13C NMR (75 MHz, CD2Cl2): δ = 150.1, 140.1, 138.3, 138.2, 138.0, 129.8, 129.0, 125.3, 124.9,
123.1, 121.2, 120.2, 118.7, 114.4, 108.5, 23.0 ppm; IR (ATR): ṽ = 3254, 3050, 2977, 1786, 1682,
1602, 1541, 1499, 1442, 1380, 1365, 1322, 1294, 1272, 1245, 1215, 1200, 1177, 1151, 1113, 1068,
1028, 955, 878, 847, 806, 752, 734, 692, 673, 633 cm-1; HRMS (ESI): calculated for
C18H16N2ONa [M+Na]+ : 299.1155, found 299.1156.

4k