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The Journal of Organic Chemistry
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1H NMR (400 MHz, CDCl3) δ 7.39 (d, J = 7.7 Hz, 1H, ArꢀH), 7.30 (t, J = 6.5 Hz, 1H, ArꢀH), 7.20 (t, J
= 7.8 Hz, 1H, ArꢀH), 6.37 (s, 1H, ArꢀH), 4.17 (dd, J = 10.7, 7.2 Hz, 1H, CF2CHH), 4.03 (dd, J = 10.8,
7.2 Hz, 1H, CF2CHH), 3.37 (d, J = 18.1 Hz, 1H, COCHH), 2.98 (d, J = 18.1 Hz, 1H, COCHH),
2.72ꢀ2.57 (m, 2H, CO2CH2), 1.61 (s, 3H, CCH3), 1.23 (t, J = 7.1 Hz, 3H, CH2CH3); 13C NMR (101
MHz, CDCl3) δ 167.7, 163.7 (t, J = 32.0 Hz), 152.1, 137.6, 128.9, 126.0, 125.1, 120.1, 119.2, 115.4
(dd, J = 253.4, 251.8 Hz), 100.1, 63.3, 48.9 (dd, J = 3.4, 1.2 Hz), 43.9 (t, J = 22.4 Hz), 34.5 (dd, J =
3.1, 1.7 Hz), 28.7 (d, J = 2.1 Hz), 13.7; 19F NMR (376 MHz, CDCl3) δ ꢀ100.16 (ddd, J = 266.6, 18.6,
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14.7 Hz), ꢀ104.10 (dt, J = 266.7, 17.2 Hz); HRMS (ESI) exact mass calculated for C17H17ClF2NO3
[M+H+]: 356.0860, found: 356.0864; IR (neat): νmax (cmꢀ1) = 1756, 1603, 1557, 1412, 1321, 1267,
1189, 865, 733; Rf = 0.3 (petroleum ether/EtOAc 15:1).
Ethyl 3-(1,5-dimethyl-3-oxo-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)-2,2-difluoropropanoate (3s).
According to general procedure with 1s and 2a, 3s was obtained in 68% yield (45 mg, yellow oil). 1H
NMR (400 MHz, CDCl3) δ 7.31 (d, J = 7.7 Hz, 1H, ArꢀH), 7.18 (t, J = 7.6 Hz, 1H, ArꢀH), 7.08 (d, J =
7.3 Hz, 1H, ArꢀH), 6.32 (s, 1H, ArꢀH), 4.13 (dd, J = 10.7, 7.2 Hz, 1H, CF2CHH), 3.98 (dd, J = 10.8,
7.2 Hz, 1H, CF2CHH), 3.35 (d, J = 18.1 Hz, 1H, COCHH), 2.95 (d, J = 18.2 Hz, 1H, COCHH), 2.90 (s,
3H, ArꢀCH3), 2.75ꢀ2.51 (m, 2H, CO2CH2), 1.60 (s, 3H, CCH3), 1.20 (t, J = 7.2 Hz, 3H, CH2CH3); 13C
NMR (101 MHz, CDCl3) δ 179.9, 174.6, 169.1 (d, J = 1.1 Hz), 163.8, 151.0, 138.6, 136.3, 135.6, 130.9,
130.3, 129.4, 126.7, 125.7, 124.6, 118.1, 115.1 (dd, J = 252.5, 254.6 Hz), 100.4, 49.0 (d, J = 2.6 Hz),
44.1 (dd, J = 21.9, 22.6 Hz), 34.5 (dd, J = 3.5, 1.7 Hz), 28.8, 21.6, 13.6; 19F NMR (376 MHz, CDCl3) δ
ꢀ99.71 (dt, J = 266.3, 16.1 Hz), ꢀ104.35 (dt, J = 266.4, 17.4 Hz); HRMS (ESI) exact mass calculated
for C18H20F2NO3+ [M+H+]: 336.1406, found: 336.1408; IR (neat): νmax (cmꢀ1) = 1709, 1605, 1589, 1403,
1367, 1271, 1190, 769, 745; Rf = 0.3 (petroleum ether/EtOAc 15:1).
Ethyl 3-(1,9-dimethyl-3-oxo-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)-2,2-difluoropropanoate (3t).
According to general procedure with 1t and 2a, 3t were obtained in 49% yield (35 mg, yellow oil). 1H
NMR (400 MHz, CDCl3) δ 8.21ꢀ7.96 (m, 1H, ArꢀH), 7.46 (dd, J = 7.3, 1.9 Hz, 1H, ArꢀH), 7.40ꢀ7.22
(m, 2H, 2(ArꢀH)), 4.00 (dd, J = 10.8, 7.1 Hz, 1H, CF2CHH), 3.71 (dd, J = 10.8, 7.1 Hz, 1H, CF2CHH),
3.40 (d, J = 18.3 Hz, 1H, COCHH), 2.93 (dd, J = 18.2, 1.7 Hz, 1H, COCHH), 2.87ꢀ2.52 (m, 2H,
CO2CH2), 2.27 (s, 3H, ArꢀCH3), 1.64 (s, 3H, CCH3), 1.07 (t, J = 7.1 Hz, 3H, CH2CH3); 13C NMR (101
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