3.2. General Procedure for the Pd-Catalyzed Asymmetric Allylic Alkylation of Indoles
Ligand L1 (5.0 mg, 4 mol%) and [Pd(C3H5)Cl]2 (2.2 mg, 2 mol%) were dissolved in toluene (1.0 mL) in a Schlenk tube under Ar. After 0.5 h of stirring at room temperature, allylic acetate 2 (0.36 mmol) dissolved in toluene (0.5 mL) was added, followed by indole 1 (0.3 mmol), and Cs2CO3 (195 mg, 0.6 mmol). The mixture was stirred at room temperature for 12 h and then was diluted with CH2Cl2 and washed with saturated NH4Cl (aq). The organic layers were dried over MgSO4 and filtered, and the solvents were evaporated in vacuo. The residue was purified by flash column chromatography, eluting with petroleum ether and ethyl acetate to afford the corresponding product 3.
(S,E)-3-(1,3-diphenylallyl)-1H-indole (
3a) [
15]: Yellow solid (m.p. 121–123 °C), 95% yield.
1H-NMR (500 MHz, CDCl
3) δ 7.98 (brs, 1H), 7.45 (d,
J = 8.0 Hz, 1H), 7.39–7.19 (m, 12H), 7.04 (t, 7.4 Hz, 1H), 6.91 (s, 1H), 6.76 (dd,
J = 15.8, 7.4 Hz, 1H), 6.47 (d,
J = 15.8 Hz, 1H), 5.14 (d,
J = 7.4 Hz, 1H);
13C-NMR (125 MHz, CDCl
3) δ 143.3, 137.4, 136.6, 132.5, 130.5, 128.4, 128.3, 127.1, 126.7, 126.3, 126.2, 122.5, 122.0, 119.8, 119.3, 118.6, 111.0, 46,1.
(S,E)-3-(1,3-diphenylallyl)-2-methyl-1H-indole (
3b) [
15]: Yellow solid (m.p. 39–41 °C), 89% yield.
1H-NMR (500 MHz, CDCl
3) δ 7.83 (brs, 1H), 7.40–7.36 (m, 5H), 7.31–7.28 (m, 5H), 7.23–7.21 (m, 2H), 7.12 (t,
J = 7.3 Hz, 1H), 7.00 (t,
J = 7.5 Hz, 1H), 6.88 (dd,
J = 15.8, 7.2 Hz, 1H), 6.45 (d,
J = 15.8 Hz, 1H), 5.17 (d,
J = 7.2 Hz, 1H), 2.40 (s, 3H);
13C-NMR (125 MHz, CDCl
3) δ 143.4, 137.5, 135.3, 132.1, 131.6, 130.5, 128.4, 128.3, 128.2, 127.9, 127.0, 126.2, 126.1, 120.9, 119.4, 119.2, 112.8, 110.2, 45.0, 12.4.
(S,E)-3-(1,3-diphenylallyl)-2-phenyl-1H-indole (
3c) [
15]: Yellow solid (m.p. 40–42 °C), 85% yield.
1H-NMR (500 MHz, CDCl
3) δ 8.09 (brs, 1H), 7.53 (d,
J = 7.4 Hz, 2H), 7.45–7.31 (m, 9H), 7.26–7.24 (m, 4H), 7.19–7.14 (m, 3H), 6.99 (t,
J = 7.6 Hz, 1H), 6.90 (dd,
J = 15.8, 7.3 Hz, 1H), 6.40 (d,
J = 15.8 Hz, 1H), 5.27 (d,
J = 8.4 Hz, 1H);
13C-NMR (125 MHz, CDCl
3) δ 143.4, 137.4, 136.2, 135.5, 132.9, 132.2, 131.0, 128.7, 128.6, 128.5, 128.4, 128.2, 128.1, 128.0, 127.8, 127.0, 126.2, 126.0, 122.0, 121.1, 119.6, 113.8, 110.8, 45.1.
(S,E)-3-(1,3-diphenylallyl)-4-methyl-1H-indole (
3d) [
17]: White solid (m.p. 172–174 °C), 93% yield.
1H-NMR (500 MHz, CDCl
3) δ 8.00 (brs, 1H), 7.35 (d,
J = 7.4 Hz, 2H), 7.32–7.26 (m, 6H), 7.25–7.18 (m, 3H), 7.07 (t,
J = 7.5 Hz, 1H), 6.86 (d,
J = 2.2 Hz, 1H), 6.81 (d,
J = 7.0 Hz, 1H), 6.75 (dd,
J = 15.8, 6.6 Hz, 1H), 6.25 (d,
J = 15.8 Hz, 1H), 5.46 (d,
J = 6.4 Hz, 1H), 2.53 (s, 3H);
13C-NMR (125 MHz, CDCl
3) δ 144.1, 137.6, 137.1, 134.0, 131.2, 130.8, 129.0, 128.6, 127.2, 126.4, 125.7, 123.6, 122.3, 121.4, 119.1, 109.1, 46.6, 20.5.
(S,E)-3-(1,3-diphenylallyl)-4-methoxy-1H-indole (3e): Yellow oil, 95% yield. 1H-NMR (500 MHz, CDCl3) δ 7.96 (brs, 1H), 7.36 (d, J = 7.6 Hz, 2H), 7.31–7.25 (m, 6H), 7.19–7.16 (m, 2H), 7.07 (t, J = 8.0 Hz, 1H), 6.96 (d, J = 8.2 Hz, 1H), 6.83 (d, J = 1.8 Hz, 1H), 6.77 (dd, J = 15.8, 7.2 Hz, 1H), 6.45 (d, J = 7.8 Hz, 1H), 6.35 (d, J = 15.8 Hz, 1H), 5.55 (d, J = 7.2 Hz, 1H), 3.73 (s, 3H); 13C-NMR (125 MHz, CDCl3) δ 154.8, 144.7, 138.1, 137.9, 134.0, 129.9, 128.5, 128.4, 128.0, 126.8, 126.2, 125.7, 122.9, 121.1, 119.3, 117.0, 104.3, 100.0, 55.0, 46.3. HRMS (ESI): calcd for C24H21NNaO [M + Na]+: 362.1515, found 362.1510.
(S,E)-3-(1,3-diphenylallyl)-5-methyl-1H-indole (
3f) [
15]: White solid (m.p. 113–114 °C), 96% yield.
1H-NMR (500 MHz, CDCl
3) δ 7.90 (brs, 1H), 7.38–7.26 (m, 8H), 7.25–7.19 (m, 4H), 7.01 (d, 8.2 Hz, 1H), 6.86 (s, 1H), 6.73 (dd,
J = 15.8, 7.3 Hz, 1H), 6.44 (d,
J = 15.8 Hz, 1H), 5.11 (d,
J = 7.2 Hz, 1H), 2.38 (s, 3H);
13C-NMR (125 MHz, CDCl
3) δ 143.6, 137.7, 135.0, 132.8, 130.6, 128.6, 127.2, 126.4, 123.8, 122.9, 119.5, 118.2, 110.9, 46.1, 21.6.
(S,E)-3-(1,3-diphenylallyl)-5-methoxy-1H-indole (
3g) [
15]: Colorless oil, 98% yield.
1H-NMR (500 MHz, CDCl
3) δ 7.90 (brs, 1H), 7.38–7.19 (m, 11H), 6.89–6.83 (m, 3H), 6.74 (dd,
J = 15.8, 7.4 Hz, 1H), 6.47 (d,
J = 15.8 Hz, 1H), 5.09 (d,
J = 7.3 Hz, 1H), 3.72 (s, 3H);
13C-NMR (125 MHz, CDCl
3) δ 154.0, 143.5, 137.7, 132.7, 132.0, 130.8, 128.7, 128.6, 127.4, 127.3, 126.6, 126.5, 123.6, 118.6, 112.4, 111.9, 102.0, 56.0, 46.4.
(S,E)-5-(benzyloxy)-3-(1,3-diphenylallyl)-1H-indole (
3h) [
15]: Colorless oil, 97% yield.
1H-NMR (500 MHz, CDCl
3) δ 7.82 (brs, 1H), 7.37–7.17 (m, 16H), 6.92–6.88 (m, 2H), 6.82 (s, 1H), 6.70 (dd,
J = 15.8, 7.4 Hz, 1H), 6.43 (d,
J = 15.8 Hz, 1H), 5.04 (d,
J = 7.3 Hz, 1H), 4.93 (s, 2H);
13C-NMR (125 MHz, CDCl
3) δ 152.9, 143.3, 137.6, 137.5, 132.4, 131.9, 130.5, 128.5, 127.7, 127.6, 127.2, 126.4, 126.3, 123.5, 118.3, 112.9, 111.8, 103.4, 70.8, 46.2.
(S,E)-5-chloro-3-(1,3-diphenylallyl)-1H-indole (
3i) [
15]: Yellow oil, 95% yield.
1H-NMR (500 MHz, CDCl
3) δ 8.01 (brs, 1H), 7.38–7.20 (m, 12H), 7.13–7.11 (m, 1H), 6.94 (s, 1H), 6.69 (dd,
J = 15.8, 7.3 Hz, 1H), 6.43 (d,
J = 15.8 Hz, 1H), 5.07 (d,
J = 7.3 Hz, 1H);
13C-NMR (125 MHz, CDCl
3) δ 143.0, 137.4, 135.0, 132.1, 130.9, 128.6, 128.5, 128.0, 127.3, 126.6, 126.4, 125.2, 124.0, 122.5, 119.3, 118.6, 112.2, 46.0.
(S,E)-5-bromo-3-(1,3-diphenylallyl)-1H-indole (
3j) [
15]: Colorless oil, 92% yield.
1H-NMR (500 MHz, CDCl
3) δ 8.00 (brs, 1H), 7.53 (s, 1H), 7.36 (d,
J = 7.6 Hz, 2H), 7.32–7.28 (m, 5H), 7.26–7.19 (m, 5H), 6.90 (d,
J = 2.2 Hz, 1H), 6.69 (dd,
J = 15.8, 7.3 Hz, 1H), 6.42 (d,
J = 15.8 Hz, 1H), 5.05 (d,
J = 7.3 Hz, 1H);
13C-NMR (125 MHz, CDCl
3) δ 142.8, 137.2, 135.2, 132.0, 130.7, 128.4, 128.3, 127.2, 126.5, 126.3, 125.0, 123.8, 122.2, 118.4, 112.7, 112.5, 45.8.
(S,E)-3-(1,3-diphenylallyl)-6-methyl-1H-indole (
3k) [
20]: Yellow oil, 90% yield.
1H-NMR (500 MHz, CDCl
3) δ 7.85 (brs, 1H), 7.37–7.17 (m, 11H), 7.14 (s, 1H), 6.86–6.83 (m, 2H), 6.74 (dd,
J = 15.8, 7.4 Hz, 1H), 6.45 (d,
J = 15.8 Hz, 1H), 5.09 (d,
J = 7.4 Hz, 1H), 2.43 (s, 3H);
13C-NMR (125 MHz, CDCl
3) δ 143.4, 137.5, 137.1, 132.6, 131.8, 130.4, 128.4, 128.3, 127.1, 126.3, 124.6, 121.9, 121.1, 119.5, 118.4, 111.0, 46.2, 21.6.
(S,E)-6-chloro-3-(1,3-diphenylallyl)-1H-indole (
3l) [
20]: Yellow oil, 94% yield.
1H-NMR (500 MHz, CDCl
3) δ 8.01 (brs, 1H), 7.38–7.28 (m, 10H), 7.26–7.20 (m, 2H), 7.00 (dd,
J = 8.5, 1.8 Hz, 1H), 6.91 (d,
J = 2.0 Hz, 1H), 6.72 (dd,
J = 15.8, 7.4 Hz, 1H), 6.44 (d,
J = 15.8 Hz, 1H), 5.09 (d,
J = 7.4 Hz, 1H);
13C-NMR (125 MHz, CDCl
3) δ 143.0, 137.2, 137.0, 132.1, 130.8, 128.5, 128.4, 128.0, 127.3, 126.6, 126.3, 125.4, 123.3, 120.8, 120.2, 118.9, 111.1, 46.1.
(S,E)-3-(1,3-diphenylallyl)-7-methyl-1H-indole (
3m) [
19]: Yellow oil, 90% yield.
1H-NMR (500 MHz, CDCl
3) δ 7.89 (brs, 1H), 7.41–7.30 (m, 9H), 7.28-7.22 (m, 2H), 7.03–6.98 (m, 2H), 6.92 (s, 1H), 6.78 (dd,
J = 15.8, 7.3 Hz, 1H), 6.49 (d,
J = 15.8 Hz, 1H), 5.16 (d,
J = 7.2 Hz, 1H), 2.50 (s, 3H);
13C-NMR (125 MHz, CDCl
3) δ 143.4, 137.5, 136.2, 132.5, 130.5, 128.4, 128.3, 127.1, 126.3, 122.6, 122.3, 120.2, 119.6, 119.1, 117.6, 46.2, 16.5.
(S,E)-3-(1,3-diphenylallyl)-7-methoxy-1H-indole (3n): Yellow oil, 86% yield. 1H-NMR (500 MHz, CDCl3) δ 8.21 (brs, 1H), 7.37–7.17 (m, 10H), 7.03 (d, J = 8.0 Hz, 1H), 6.95-6.88 (m, 2H), 6.74 (dd, J = 15.8, 7.4 Hz, 1H), 6.63 (d, J = 7.6 Hz, 1H), 6.44 (d, J = 15.8 Hz, 1H), 5.10 (d, J = 7.4 Hz, 1H), 3.94 (s, 3H); 13C-NMR (125 MHz, CDCl3) δ 146.1, 143.5, 137.5, 132.6, 130.5, 128.4, 128.2, 127.1, 122.2, 119.8, 119.1, 112.7, 101.9, 55.3, 46.3. HRMS (ESI): calcd for C24H21NNaO [M+Na]+: 362.1515, found 362.1516.
(S,E)-7-chloro-3-(1,3-diphenylallyl)-1H-indole (3o): Yellow solid (m.p. 81–82 °C), 90% yield. 1H-NMR (500 MHz, CDCl3) δ 8.23 (brs, 1H), 7.38–7.28 (m, 9H), 7.24–7.17 (m, 3H), 6.98–6.94 (m, 2H), 6.73 (dd, J = 15.8, 7.3 Hz, 1H), 6.45 (d, J = 15.8 Hz, 1H), 5.11 (d, J = 7.3 Hz, 1H); 13C-NMR (125 MHz, CDCl3) δ 143.0, 137.3, 133.9, 132.1, 130.9, 128.5, 128.4, 128.3, 127.3, 126.6, 126.4, 123.3, 121.5, 120.3, 119.9, 118.6, 116.6, 46.2. HRMS (ESI): calcd for C23H18ClNNa [M + Na]+: 366.1020, found 366.1018.
(S,E)-3-(1,3-di-p-tolylallyl)-1H-indole (
3p) [
19]: Yellow oil, 92% yield.
1H-NMR (500 MHz, CDCl
3) δ 7.97 (brs, 1H), 7.46 (d, J = 8.0 Hz, 1H), 7.37 (d,
J = 8.1 Hz, 1H), 7.28–7.02 (m, 10H), 6.91 (s, 1H), 6.70 (dd,
J = 15.8, 7.4 Hz, 1H), 6.44 (d,
J = 15.8 Hz, 1H), 5.09 (d,
J = 7.2 Hz, 1H), 2.35 (s, 3H), 2.33 (s, 3H);
13C-NMR (125 MHz, CDCl
3) δ 140.7, 137.0, 136.8, 136.0, 135.0, 132.0, 130.4, 129.4, 129.3, 128.6, 127.0, 126.4, 122.8, 122.2, 120.1, 119.6, 119.2, 111.3, 46.0, 21.3.
(S,E)-3-(1,3-bis(4-methoxyphenyl)allyl)-1H-indole (
3q) [
43]: Yellow oil, 85% yield.
1H-NMR (500 MHz, CDCl
3) δ 7.98 (s, 1H), 7.43–7.28 (m, 4H), 7.24 (d,
J = 8.2 Hz, 2H), 7.16 (t,
J = 7.6 Hz, 1H), 7.02 (t,
J = 7.6 Hz, 1H), 6.89 (s, 1H), 6.85–6.81 (m, 4H), 6.56 (dd,
J = 15.8, 7.3 Hz, 1H), 6.36 (d,
J = 15.8 Hz, 1H), 5.05 (d,
J = 7.3 Hz, 1H), 3.78 (s, 6H);
13C-NMR (125 MHz, CDCl
3) δ 158.9, 158.1, 136.7, 135.8, 130.8, 130.4, 129.7, 129.5, 127.5, 126.9, 122.6, 122.0, 120.0, 119.4, 119.2, 113.9, 113.8, 111.2, 55.3, 55.2, 45.4.
(S,E)-3-(1,3-bis(4-chlorophenyl)allyl)-1H-indole (
3r) [
19]: Yellow oil, 91% yield.
1H-NMR (500 MHz, CDCl
3) δ 8.05 (brs, 1H), 7.39 (d,
J = 8.2 Hz, 2H), 7.30–7.19 (m, 9H), 7.06 (t,
J = 7.5 Hz, 1H), 6.92 (s, 1H), 6.69 (dd,
J = 15.8, 7.2 Hz, 1H), 6.38 (d,
J = 15.8 Hz, 1H), 5.11 (d,
J = 7.2 Hz, 1H);
13C-NMR (125 MHz, CDCl
3) δ 141.8, 136.9, 135.9, 133.1, 132.8, 132.4, 130.0, 129.9, 128.9, 128.8, 127.7, 126.7, 122.8, 122.5, 119.9, 119.8, 118.2, 111.4, 45.7.
(S,E)-3-(1,3-bis(4-nitrophenyl)allyl)-1H-indole (3s): Yellow oil, 87% yield. 1H-NMR (500 MHz, CDCl3) δ 8.23–8.11 (m, 5H), 7.50–7.32 (m, 6H), 7.22 (t, J = 7.4 Hz, 1H), 7.06 (t, J = 7.5 Hz, 1H), 6.98 (s, 1H), 6.90 (dd, J = 15.8, 7.2 Hz, 1H), 6.5 (d, J = 15.8 Hz, 1H), 5.28 (d, J = 8.0 Hz, 1H); 13C-NMR (125 MHz, CDCl3) δ 150.2, 146.8, 143.4, 136.7, 135.7, 130.0, 129.4, 127.0, 126.2, 124.0, 123.9, 122.8, 122.7, 119.9, 119.2, 116.2, 111.6, 46.1. HRMS (ESI): calcd for C23H17N3NaO4 [M + Na]+: 422.1111, found 422.1110.
3.3. General Procedure for the N-Boc Protection of Alkylated Indoles
To a solution of 3 (0.15 mmol) and DMAP (0.9 mg, 0.0075 mmol) in CH2Cl2 (3 mL) was added (Boc)2O (49 mg, 0.225 mmol), and the solution was stirred for 0.5 h at room temperature. The resulting mixture was evaporated under reduced pressure and purified by flash column chromatography (elution with n-hexane/EtOAc = 30:1) to afford the N-Boc-protected alkylated indole (Boc-3).
(S,E)-tert-butyl 3-(1,3-diphenylallyl)-1H-indole-1-carboxylate (
Boc-3a) [
15]: Colorless oil. 99% yield and 96% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.4 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 13.2 min for (
S)-isomer (major), t
r = 16.0 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 8.12 (brs, 1H), 7.39–7.21 (m, 13H), 7.14 (t,
J = 7.6 Hz, 1H), 6.72 (dd,
J = 15.8, 7.4 Hz, 1H), 6.46 (d,
J = 15.8 Hz, 1H), 5.06 (d,
J = 7.4 Hz, 1H), 1.68 (s, 9H);
13C-NMR (125 MHz, CDCl
3) δ 150.0, 142.1, 137.3, 135.8, 131.4, 131.3, 129.9, 128.6, 128.5, 128.4, 127.4, 126.8, 126.4, 124.4, 123.8, 123.1, 122.5, 120.2, 115.3, 83.7, 46.0, 28.3.
(S,E)-tert-butyl 3-(1,3-diphenylallyl)-2-methyl-1H-indole-1-carboxylate (
Boc-3b) [
15]: Colorless oil. 99% yield and 96% ee, determined by chiral HPLC analysis (Chiralcel OJ-H hexane/isopropanol, 99:1
v/
v, 0.3 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 37.2 min for (
R)-isomer (minor), t
r = 50.1 min for (
S)-isomer (major).
1H-NMR (500 MHz, CDCl
3) δ 8.14 (d,
J = 8.4 Hz, 1H), 7.39 (d,
J = 7.5 Hz, 2H), 7.34–7.27 (m, 7H), 7.23–7.19 (m, 3H), 7.07 (t,
J = 7.5 Hz, 1H), 6.83 (dd,
J = 15.8, 7.4 Hz, 1H), 6.48 (d,
J = 16.0 Hz, 1H), 5.20 (d,
J = 7.4 Hz, 1H), 2.62 (s, 3H), 1.70 (s, 9H);
13C-NMR (125 MHz, CDCl
3) δ 150.7, 142.3, 137.2, 136.0, 134.0, 131.5, 130.5, 128.9, 128.5, 128.3, 128.0, 127.2, 126.3, 123.1, 122.2, 119.5, 119.1, 115.3, 83.6, 44.5, 28.3, 14.3.
(S,E)-tert-butyl 3-(1,3-diphenylallyl)-2-phenyl-1H-indole-1-carboxylate (
Boc-3c) [
15]: White solid (m.p. 153–155 °C). 98% yield and 86% ee, determined by chiral HPLC analysis (Chiralcel AD-H hexane/isopropanol, 99:1
v/
v, 0.8 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 5.1 min for (
S)-isomer (major), t
r = 13.4 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 8.29 (d,
J = 8.6 Hz, 1H), 7.42–7.36 (m, 5H), 7.33–7.17 (m, 12H), 7.10 (t,
J = 7.8 Hz, 1H), 6.77 (dd,
J = 15.8, 7.6 Hz, 1H), 6.32 (d,
J = 15.8 Hz, 1H), 4.85 (d,
J = 7.6 Hz, 1H), 1.22 (s, 9H);
13C-NMR (125 MHz, CDCl
3) δ 150.4, 142.8, 137.6, 137.2, 136.9, 134.5, 131.9, 130.9, 130.3, 128.7, 128.5, 128.4, 128.2, 128.1, 127.5, 126.6, 124.5, 122.8, 121.5, 121.2, 115.6, 83.3, 45.1, 27.8.
(S,E)-tert-butyl 3-(1,3-diphenylallyl)-4-methyl-1H-indole-1-carboxylate (
Boc-3d) [
18]: White solid (m.p. 137–139 °C). 98% yield and 84% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.7 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 7.1 min for (
S)-isomer (major), t
r = 8.5 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 8.07 (brs, 1H), 7.38 (d,
J = 7.4 Hz, 2H), 7.35–7.25 (m, 8H), 7.24–7.19 (m, 2H), 6.94 (d,
J = 7.3 Hz, 1H), 6.73 (dd,
J = 15.8, 6.6 Hz, 1H), 6.31 (d,
J = 15.8 Hz, 1H), 5.37 (d,
J = 6.6 Hz, 1H), 2.50 (s, 3H), 1.68 (s, 9H);
13C-NMR (125 MHz, CDCl
3) δ 149.9, 142.8, 137.4, 136.4, 132.7, 131.3, 131.2, 128.9, 128.6, 127.4, 126.7, 126.5, 125.0, 124.9, 124.4, 123.5, 113.2, 83.7, 46.6, 28.3, 27.5, 20.4.
(S,E)-tert-butyl 3-(1,3-diphenylallyl)-4-methoxy-1H-indole-1-carboxylate (Boc-3e): Colorless oil. 99% yield and 92% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1 v/v, 0.7 mL/min, 25 °C, UV 254 nm), Retention times: tr = 7.8 min for (S)-isomer (major), tr = 11.6 min for (R)-isomer (minor). 1H-NMR (500 MHz, CDCl3) δ 7.73 (brs, 1H), 7.37 (d, J = 7.5 Hz, 2H), 7.30–7.27 (m, 7H), 7.20 (t, J = 7.8 Hz, 3H), 6.73 (dd, J = 15.8, 7.4 Hz, 1H), 6.60 (d, J = 8.0 Hz, 1H), 6.37 (d, J = 15.8 Hz, 1H), 5.46 (d, J = 7.4 Hz, 1H), 3.70 (s, 3H), 1.66 (s, 9H); 13C-NMR (125 MHz, CDCl3) δ 154.3, 150.0, 143.5, 137.7, 137.3, 132.9, 130.5, 128.5, 128.2, 127.1, 126.4, 126.1, 125.3, 123.4, 122.6, 119.6, 108.3, 103.8, 93.7, 55.2, 46.5, 28.3. HRMS (ESI): calcd for C29H29NNaO3 [M + Na]+: 462.2040, found 462.2033.
(S,E)-tert-butyl 3-(1,3-diphenylallyl)-5-methyl-1H-indole-1-carboxylate (
Boc-3f) [
15]: White solid (m.p. 151–152 °C). 98% yield and 95% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.7 mL/min, 25 °C, ultraviolet (UV) 254 nm), Retention times: t
r = 7.5 min for (
S)-isomer (major), t
r = 8.9 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.96 (brs, 1H), 7.37–7.27 (m, 9H), 7.25–7.19 (m, 2H), 7.12–7.09 (m, 2H), 6.68 (dd,
J = 15.8, 7.3 Hz, 1H), 6.42 (d,
J = 15.8 Hz, 1H), 5.01 (d,
J = 7.3 Hz, 1H), 2.35 (s, 3H), 1.65 (s, 9H);
13C-NMR (125 MHz, CDCl
3) δ 150.0, 142.2, 137.3, 134.0, 131.9, 131.4, 131.3, 130.1, 128.6, 128.5, 127.4, 126.7, 126.4, 125.8, 123.9, 122.8, 119.9, 114.9, 83.5, 45.9, 28.3, 21.5.
(S,E)-tert-butyl 3-(1,3-diphenylallyl)-5-methoxy-1H-indole-1-carboxylate (
Boc-3g) [
15]: Yellow oil. 98% yield and 98% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.7 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 8.0 min for (
S)-isomer (major), t
r = 10.2 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.99 (brs, 1H), 7.39–7.22 (m, 11H), 6.91 (dd,
J = 9.0, 2.4 Hz, 1H), 6.78 (d,
J = 2.3 Hz, 1H), 6.69 (dd,
J = 15.8, 7.4 Hz, 1H), 6.46 (d,
J = 15.8 Hz, 1H), 5.00 (d,
J = 7.3 Hz, 1H), 3.73 (s, 3H), 1.67 (s, 9H);
13C-NMR (125 MHz, CDCl
3) δ 155.8, 155.0, 142.2, 137.4, 131.5, 131.3, 130.9, 128.8, 128.7, 128.6, 127.6, 126.9, 126.6, 124.7, 123.0, 116.1, 112.9, 103.3, 83.7, 55.8, 46.2, 28.4, 27.6.
(S,E)-tert-butyl 5-(benzyloxy)-3-(1,3-diphenylallyl)-1H-indole-1-carboxylate (
Boc-3h) [
15]: Colorless oil. 99% yield and 96% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.35 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 34.3 min for (
S)-isomer (major), t
r = 38.3 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 8.00 (brs, 1H), 7.38–7.30 (m, 13H), 7.28–7.22 (m, 3H), 6.99 (dd,
J = 9.0, 2.2 Hz, 1H), 6.86 (d,
J = 2.2 Hz, 1H), 6.69 (dd,
J = 15.8, 7.4 Hz, 1H), 6.45 (d,
J = 15.8 Hz, 1H), 4.98 (d,
J = 5.0 Hz, 3H), 1.67 (s, 9H);
13C-NMR (125 MHz, CDCl
3) δ 154.9, 150.0, 142.2, 137.4, 131.5, 131.3, 130.9, 128.8, 128.7, 128.6, 128.0, 127.7, 127.6, 126.9, 126.6, 124.7, 123.0, 116.2, 113.9, 104.7, 83.7, 70.8, 46.2, 28.4.
(S,E)-tert-butyl 5-chloro-3-(1,3-diphenylallyl)-1H-indole-1-carboxylate (
Boc-3i) [
15]: White solid (m.p. 54–56 °C). 99% yield and 92% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.7 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 8.2 min for (
S)-isomer (major), t
r = 9.0 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 8.02 (brs, 1H), 7.37–7.27 (m, 10H), 7.24–7.20 (m, 2H), 6.64 (dd,
J = 15.8, 7.3 Hz, 1H), 6.42 (d,
J = 15.8 Hz, 1H), 4.98 (d,
J = 7.3 Hz, 1H), 1.65 (s, 9H);
13C-NMR (125 MHz, CDCl
3) δ 149.6, 141.7, 137.1, 134.2, 131.6, 131.1, 130.8, 128.7, 128.6, 128.4, 128.2, 127.5, 127.0, 126.4, 125.1, 124.6, 122.5, 119.6, 116.4, 84.2, 45.8, 28.2.
(S,E)-tert-butyl 5-bromo-3-(1,3-diphenylallyl)-1H-indole-1-carboxylate (
Boc-3j) [
15]: White solid (m.p. 72–73 °C). 96% yield and 93% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.7 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 8.2 min for (
S)-isomer (major), t
r = 8.8 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.99 (brs, 1H), 7.46 (s, 1H), 7.38–7.36 (m, 4H), 7.33–7.27 (m, 6H), 7.26–7.21 (m, 2H), 6.67 (dd,
J = 15.8, 7.3 Hz, 1H), 6.43 (d,
J = 15.8 Hz, 1H), 4.99 (d,
J = 7.3 Hz, 1H), 1.65 (s, 9H);
13C-NMR (125 MHz, CDCl
3) δ 149.4, 141.5, 137.0, 134.5, 131.5, 131.4, 130.7, 128.6, 128.4, 128.2, 127.4, 127.2, 126.8, 126.3, 124.8, 122.5, 122.3, 116.6, 115.8, 84.1, 45.6, 28.1.
(S,E)-tert-butyl 3-(1,3-diphenylallyl)-6-methyl-1H-indole-1-carboxylate (Boc-3k): White solid (m.p. 121–123 °C). 99% yield and 93% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1 v/v, 0.7 mL/min, 25 °C, UV 254 nm), Retention times: tr = 7.2 min for (S)-isomer (major), tr = 8.2 min for (R)-isomer (minor). 1H-NMR (500 MHz, CDCl3) δ 7.97 (brs, 1H), 7.37–7.18 (m, 12H), 6.96 (d, J = 8.0 Hz, 1H), 6.69 (dd, J = 15.8, 7.4 Hz, 1H), 6.44 (d, J = 15.8 Hz, 1H), 5.01 (d, J = 7.4 Hz, 1H), 2.44 (s, 3H), 1.65 (s, 9H); 13C-NMR (125 MHz, CDCl3) δ 150.0, 142.2, 137.3, 136.3, 134.4, 131.3, 131.2, 128.6, 128.5, 128.4, 127.6, 127.4, 126.7, 126.4, 123.9, 123.1, 123.0, 119.7, 115.6, 83.5, 46.0, 28.2, 22.0. HRMS (ESI): calcd for C29H29NNaO2 [M + Na]+: 446.2091, found 446.2093.
(S,E)-tert-butyl 6-chloro-3-(1,3-diphenylallyl)-1H-indole-1-carboxylate (Boc-3l): Colorless oil. 98% yield and 93% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1 v/v, 0.7 mL/min, 25 °C, UV 254 nm), Retention times: tr = 8.5 min for (S)-isomer (major), tr = 9.2 min for (R)-isomer (minor). 1H-NMR (500 MHz, CDCl3) δ 8.14 (brs, 1H), 7.36–7.19 (m, 12H), 7.10 (dd, J = 8.3, 1.7 Hz, 1H), 6.67 (dd, J = 15.8, 7.4 Hz, 1H), 6.43 (d, J = 15.8 Hz, 1H), 5.00 (d, J = 7.3 Hz, 1H), 1.66 (s, 9H); 13C-NMR (125 MHz, CDCl3) δ 171.2, 149.5, 141.8, 137.1, 136.2, 131.5, 130.9, 130.4, 128.7, 128.6, 128.4, 127.5, 126.9, 126.4, 124.3, 123.0, 122.9, 120.9, 115.6, 84.3, 60.4, 45.9, 28.2, 21.1, 14.2. HRMS (ESI): calcd for C28H26ClNNaO2 [M + Na]+: 466.1544, found 466.1547.
(S,E)-tert-butyl 3-(1,3-diphenylallyl)-7-methyl-1H-indole-1-carboxylate (
Boc-3m) [
19]: White solid (m.p. 123–124 °C). 99% yield and 83% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.7 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 7.6 min for (
S)-isomer (major), t
r = 8.9 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.39–7.28 (m, 9H), 7.26–7.18 (m, 3H), 7.09–7.04 (m, 2H), 6.71 (dd,
J = 15.8, 7.4 Hz, 1H), 6.45 (d,
J = 15.8 Hz, 1H), 5.03 (d,
J = 7.4 Hz, 1H), 2.64 (s, 3H), 1.63 (s, 9H);
13C-NMR (125 MHz, CDCl
3) δ 149.6, 142.0, 137.2, 135.4, 131.2, 131.1, 131.0, 128.4, 128.3, 127.6, 127.2, 126.5, 126.3, 125.9, 125.3, 122.8, 122.4, 117.6, 83.2, 45.8, 28.0, 22.1.
(S,E)-tert-butyl 3-(1,3-diphenylallyl)-7-methoxy-1H-indole-1-carboxylate (Boc-3n): Colorless oil. 95% yield and 84% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1 v/v, 0.7 mL/min, 25 °C, UV 254 nm), Retention times: tr = 21.4 min for (S)-isomer (major), tr = 49.0 min for (R)-isomer (minor). 1H-NMR (500 MHz, CDCl3) δ 7.37 (d, J = 7.5 Hz, 2H), 7.32–7.26 (m, 7H), 7.25–7.21 (m, 2H), 7.07 (t, J = 7.9 Hz, 1H), 6.96 (d, J = 7.8 Hz, 1H), 6.80 (d, J = 7.9 Hz, 1H), 6.69 (dd, J = 15.8, 7.4 Hz, 1H), 6.43 (d, J = 15.8 Hz, 1H), 5.01 (d, J = 7.4 Hz, 1H), 3.93 (s, 3H), 1.62 (s, 9H); 13C-NMR (125 MHz, CDCl3) δ 150.0, 148.4, 142.2, 137.3, 132.8, 131.4, 131.3, 128.6, 127.4, 126.7, 126.5, 126.4, 125.2, 123.5, 122.4, 112.8, 106.9, 83.3, 55.8, 46.0, 28.1. HRMS (ESI): calcd for C29H29NNaO3 [M+Na]+: 462.2040, found 462.2043.
(S,E)-tert-butyl 7-chloro-3-(1,3-diphenylallyl)-1H-indole-1-carboxylate (Boc-3o): Colorless oil. 99% yield and 94% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1 v/v, 0.7 mL/min, 25 °C, UV 254 nm), Retention times: tr = 11.6 min for (S)-isomer (major), tr = 17.3 min for (R)-isomer (minor). 1H-NMR (500 MHz, CDCl3) δ 7.36–7.27 (m, 10H), 7.26–7.21 (m, 3H), 7.06 (t, J = 7.8 Hz, 1H), 6.67 (dd, J = 15.8, 7.4 Hz, 1H), 6.43 (d, J = 15.8 Hz, 1H), 5.00 (d, J = 7.4 Hz, 1H), 1.63 (s, 9H); 13C-NMR (125 MHz, CDCl3) δ 149.1, 141.7, 137.0, 133.2, 132.7, 131.5, 130.8, 128.6, 128.5, 128.4, 127.4, 127.3, 126.8, 126.5, 126.4, 123.4, 122.4, 120.4, 118.7, 84.5, 45.8, 27.9. HRMS (ESI): calcd for C28H26ClNNaO2 [M + Na]+: 466.1544, found 466.1539.
(S,E)-tert-butyl 3-(1,3-di-p-tolylallyl)-1H-indole-1-carboxylate (
Boc-3p) [
19]: Colorless oil. 99% yield and 94% ee, determined by chiral HPLC analysis (Chiralcel AD-H hexane/isopropanol, 99:1
v/
v, 0.5 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 12.0 min for (
S)-isomer (major), t
r = 14.1 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 8.13 (brs, 1H), 7.38 (d,
J = 8.2 Hz, 2H), 7.31–7.27 (m, 3H), 7.24–7.22 (m, 2H), 7.16–7.11 (m, 5H), 6.67 (dd,
J = 15.8, 7.4 Hz, 1H), 6.43 (d,
J = 15.8 Hz, 1H), 5.01 (d,
J = 7.7 Hz, 1H), 2.35 (s, 3H), 2.34 (s, 3H), 1.69 (s, 9H);
13C-NMR (125 MHz, CDCl
3) δ 150.1, 139.4, 137.2, 136.3, 136.0, 134.7, 131.1, 130.6, 130.1, 129.4, 129.3, 128.5, 126.4, 124.5, 123.9, 123.5, 122.6, 120.4, 115.4, 83.8, 45.7, 28.4, 21.3.
(S,E)-tert-butyl 3-(1,3-bis(4-methoxyphenyl)allyl)-1H-indole-1-carboxylate (Boc-3q): Yellow oil. 85% yield and 90% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1 v/v, 0.7 mL/min, 25 °C, UV 254 nm), Retention times: tr = 17.5 min for (S)-isomer (major), tr = 19.3 min for (R)-isomer (minor). 1H-NMR (500 MHz, CDCl3) δ 8.08 (s, 1H), 7.33–7.74 (m, 5H), 7.22 (d, J = 8.6 Hz, 2H), 7.11 (t, J = 7.5 Hz, 1H), 6.82 (t, J = 9.2 Hz, 4H), 6.51 (dd, J = 15.8, 7.2 Hz, 1H), 6.34 (d, J = 15.8 Hz, 1H), 4.95 (d, J = 7.2 Hz, 1H), 3.78 (s, 6H), 1.65 (s, 9H); 13C-NMR (125 MHz, CDCl3) δ 159.1, 158.3, 150.0, 134.4, 130.4, 130.1, 130.0, 129.4, 127.5, 124.3, 123.7, 123.6, 122.4, 120.2, 115.3, 113.9, 83.7, 55.3, 55.2, 45.1, 28.3. HRMS (ESI): calcd for C30H31NNaO4 [M + Na]+: 492.2145, found 492.2150.
(S,E)-tert-butyl 3-(1,3-bis(4-chlorophenyl)allyl)-1H-indole-1-carboxylate (
Boc-3r) [
19]: White solid (m.p. 65–67 °C). 99% yield and 95% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.7 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 8.6 min for (
S)-isomer (major), t
r = 11.7 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 8.11 (brs, 1H), 7.36 (s, 1H), 7.32–7.23 (m, 10H), 7.14 (t,
J = 7.5 Hz, 1H), 6.64 (dd,
J = 15.8, 7.2 Hz, 1H), 6.37 (d,
J = 15.8 Hz, 1H), 5.01 (d,
J = 7.2 Hz, 1H), 1.68 (s, 9H);
13C-NMR (125 MHz, CDCl
3) δ 150.0, 140.5, 136.0, 135.6, 133.3, 132.8, 131.5, 130.7, 129.9, 129.7, 129.0, 128.9, 127.8, 124.7, 124.0, 122.7, 122.4, 120.1, 115.5, 84.1, 45.4, 28.4.
(S,E)-tert-butyl 3-(1,3-bis(4-nitrophenyl)allyl)-1H-indole-1-carboxylate (Boc-3s): Yellow oil. 87% yield and 97% ee, determined by chiral HPLC analysis (Chiralcel AD-H hexane/isopropanol, 93:7 v/v, 1.0 mL/min, 25 °C, UV 254 nm), Retention times: tr = 43.5 min for (R)-isomer (minor), tr = 54.4 min for (S)-isomer (major). 1H-NMR (500 MHz, CDCl3) δ 8.21–8.12 (m, 5H), 7.50 (d, J = 7.2 Hz, 4H), 7.42 (s, 1H), 7.33 (t, J = 7.6 Hz, 1H), 7.24–7.14 (m, 2H), 6.85 (dd, J = 15.8, 7.2 Hz, 1H), 6.51 (d, J = 15.8 Hz, 1H), 5.21 (d, J = 7.2 Hz, 1H), 1.68 (s, 9H); 13C-NMR (125 MHz, CDCl3) δ 148.7, 147.1, 142.9, 134.3, 130.7, 129.3, 129.0, 127.0, 124.9, 124.1, 122.8, 120.6, 119.5, 115.6, 84.3, 45.8, 28.2. HRMS (ESI): calcd for C28H25N3NaO6 [M + Na]+: 522.1636, found 522.1632.
3.4. General Procedure for the Pd-Catalyzed Asymmetric Allylic Etherification
Ligand L1 (5.0 mg, 4 mol%) and [Pd(C3H5)Cl]2 (2.2 mg, 2 mol%) were dissolved in DCM (1.0 mL) in a Schlenk tube under Ar. After 0.5 h of stirring at room temperature, allylic acetate 2a (0.3 mmol) dissolved in DCM (0.5 mL) was added, followed by alcohol 4 (0.9 mmol) dissolved in DCM (0.5 mL) and Cs2CO3 (195 mg, 0.9 mmol). The mixture was stirred at 0 °C for 5 h and then was diluted with CH2Cl2 and washed with saturated NH4Cl (aq). The organic layers were dried over MgSO4 and filtered, and the solvents were evaporated in vacuo. The residue was purified by flash column chromatography, eluting with petroleum ether and ethyl acetate to afford the corresponding product 5.
(S,E)-(3-(benzyloxy)prop-1-ene-1,3-diyl)dibenzene (
5a) [
44]: Colorless oil. 99% yield and 98% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.5 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 12.2 min for (
S)-isomer (major), t
r = 13.4 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.46–7.30 (m, 14H), 7.27–7.23 (m, 1H), 6.66 (d,
J = 15.9 Hz, 1H), 6.38 (dd,
J = 15.9, 7.0 Hz, 1H), 5.04 (d,
J = 7.0 Hz, 1H), 4.62-4.57 (m, 2H);
13C-NMR (125 MHz, CDCl
3) δ 141.0, 138.2, 136.5, 131.4, 130.2, 129.6, 128.4, 128.3, 127.6, 127.4, 126.9, 126.5, 81.5, 70.0.
(S,E)-(3-((4-methoxybenzyl)oxy)prop-1-ene-1,3-diyl)dibenzene (
5b) [
44]: Colorless oil. 97% yield and 97% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.5 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 18.0 min for (
S)-isomer (major), t
r = 23.8 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.44 (d,
J = 7.6 Hz, 2H), 7.38 (t,
J = 7.6 Hz, 4H), 7.32–7.29 (m, 5H), 7.23 (t,
J = 7.2 Hz, 1H), 6.91 (d,
J = 8.5 Hz, 2H), 6.63 (d,
J = 15.9 Hz, 1H), 6.36 (dd,
J = 15.9, 7.0 Hz, 1H), 5.01 (d,
J = 7.0 Hz, 1H), 4.51 (s, 2H), 3.82 (s, 3H);
13C-NMR (125 MHz, CDCl
3) δ 159.1, 141.2, 136.6, 131.4, 130.4, 130.3, 129.3, 128.5, 127.6, 126.9, 126.5, 113.7, 81.2, 69.7, 55.2.
(S,E)-(3-((4-bromobenzyl)oxy)prop-1-ene-1,3-diyl)dibenzene (
5c) [
44]: Colorless oil. 93% yield and 91% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 95:5
v/
v, 0.5 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 10.2 min for (
S)-isomer (major), t
r = 11.2 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.47 (d,
J = 8.3 Hz, 2H), 7.42-7.36 (m, 6H), 7.31–7.27 (m, 3H), 7.25–7.23 (m, 3H), 6.61 (d,
J = 15.9 Hz, 1H), 6.32 (dd,
J = 15.9, 7.1 Hz, 1H), 4.97 (d,
J = 7.1 Hz, 1H), 4.55–4.48 (m, 2H);
13C-NMR (125 MHz, CDCl
3) δ 140.9, 137.5, 136.5, 131.8, 131.5, 130.1, 129.4, 128.7, 128.6, 127.9, 127.0, 126.7, 121.4, 81.9, 69.4.
(S,E)-(3-((3-bromobenzyl)oxy)prop-1-ene-1,3-diyl)dibenzene (
5d) [
45]: Colorless oil. 95% yield and 94% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.5 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 14.3 min for (
S)-isomer (major), t
r = 15.9 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.54 (s, 1H), 7.44–7.39 (m, 7H), 7.33–7.29 (m, 4H), 7.26–7.21 (m, 2H), 6.65 (d,
J = 15.9 Hz, 1H), 6.36 (dd,
J = 15.9, 7.1 Hz, 1H), 5.02 (d,
J = 7.0 Hz, 1H), 4.58 (q,
J = 12.2 Hz, 2H);
13C-NMR (125 MHz, CDCl
3) δ 140.9, 136.5, 131.8, 130.6, 130.0, 128.6, 127.9, 127.0, 126.7, 126.1, 122.6, 82.1, 69.4.
(S,E)-(3-((2-bromobenzyl)oxy)prop-1-ene-1,3-diyl)dibenzene (
5e) [
46]: Colorless oil. 93% yield and 93% ee, determined by chiral HPLC analysis (Chiralcel OJ-H hexane/isopropanol, 99:1
v/
v, 0.3 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 73.1 min for (
S)-isomer (major), t
r = 81.9 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.69 (d,
J = 7.7 Hz, 1H), 7.64 (d,
J = 7.9 Hz, 1H), 7.57–7.47 (m, 6H), 7.45–7.39 (m, 4H), 7.35–7.24 (m, 2H), 6.80 (d,
J = 15.9 Hz, 1H), 6.47 (dd,
J = 15.9, 7.0 Hz, 1H), 5.17 (d,
J = 7.1 Hz, 1H), 4.76 (q,
J = 13.1 Hz, 2H);
13C-NMR (125 MHz, CDCl
3) δ 141.0, 137.9, 136.6, 132.9, 132.5, 131.8, 130.0, 129.2, 128.9, 128.6, 127.8, 127.4, 126.9, 126.7, 82.4, 69.8.
(S,E)-2-(((1,3-diphenylallyl)oxy)methyl)naphthalene (
5f) [
40]: Colorless oil. 97% yield and 94% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 98:2
v/
v, 1.0 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 7.3 min for (
S)-isomer (major), t
r = 10.2 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.84–7.79 (m, 4H), 7.51–7.45 (m, 5H), 7.40–7.37 (m, 4H), 7.32–7.28 (m, 3H), 7.23 (t,
J = 7.3 Hz, 1H), 6.66 (d,
J = 15.9 Hz, 1H), 6.39 (dd,
J = 15.9, 7.0 Hz, 1H), 5.06 (d,
J = 7.0 Hz, 1H), 4.74 (s, 2H);
13C-NMR (125 MHz, CDCl
3) δ 141.2, 136.7, 136.0, 133.4, 133.1, 131.7, 130.3, 128.6, 128.2, 128.0, 127.8, 127.7, 127.1, 126.7, 126.5, 126.1, 125.9, 125.8, 81.7, 70.3.
(S,E)-2-(((1,3-diphenylallyl)oxy)methyl)pyridine (
5g) [
44]: Colorless oil. 86% yield and 94% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.8 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 25.0 min for (
S)-isomer (major), t
r = 36.8 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 8.56 (d,
J = 4.6 Hz, 1H), 7.74–7.71 (m, 1H), 7.58 (d,
J = 7.8 Hz, 1H), 7.49 (d,
J = 7.4 Hz, 2H), 7.40 (t,
J = 7.4 Hz, 4H), 7.32 (t,
J = 7.6 Hz, 3H), 7.25 (t,
J = 7.3 Hz, 1H), 7.21–7.19 (m, 1H), 6.72 (d,
J = 15.8 Hz, 1H), 6.40 (dd,
J = 15.8, 7.1 Hz, 1H), 5.11 (d,
J = 7.1 Hz, 1H), 4.78 (dd,
J = 34.2, 13.5 Hz, 2H);
13C-NMR (125 MHz, CDCl
3) δ 158.7, 148.9, 140.7, 136.4, 131.7, 129.8, 128.4, 127.7, 126.8, 126.5, 122.1, 121.2, 82.5, 71.1.
(S,E)-(3-ethoxyprop-1-ene-1,3-diyl)dibenzene (
5h) [
44]: Colorless oil. 98% yield and 99% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.5 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 9.2 min for (
S)-isomer (major), t
r = 10.4 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.42–7.35 (m, 6H), 7.31–7.27 (m, 3H), 7.22 (t,
J = 7.3 Hz, 1H), 6.63 (d,
J = 15.9 Hz, 1H), 6.34 (dd,
J = 15.9, 7.1 Hz, 1H), 4.93 (d,
J = 7.1 Hz, 1H), 3.61–3.56 (m, 1H), 3.52–3.48 (m, 1H), 1.27 (t,
J = 7.0 Hz, 3H);
13C-NMR (125 MHz, CDCl
3) δ 141.6, 136.7, 131.2, 130.7, 128.5, 127.7, 127.6, 126.9, 126.6, 82.6, 64.0, 15.4.
(S,E)-(3-(but-3-en-1-yloxy)prop-1-ene-1,3-diyl)dibenzene (
5i) [
44]: Colorless oil. 97% yield and 95% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99.2:0.8
v/
v, 0.4 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 10.3 min for (
S)-isomer (major), t
r = 12.1 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.40–7.34 (m, 6H), 7.30–7.26 (m, 3H), 7.22 (t,
J = 7.4 Hz, 1H), 6.62 (d,
J = 15.9 Hz, 1H), 6.31 (dd,
J = 15.9, 7.0 Hz, 1H), 5.90–5.81 (m, 1H), 5.11–5.02 (m, 2H), 4.92 (d,
J = 7.0 Hz, 1H), 3.60–3.56 (m, 1H), 3.50–3.46 (m, 1H), 2.43 (q,
J = 6.8 Hz, 2H);
13C-NMR (125 MHz, CDCl
3) δ 141.4, 136.6, 135.3, 131.3, 130.5, 128.5, 127.7, 127.6, 126.8, 126.6, 116.3, 82.7, 68.0, 34.4.
(S,E)-2-((1,3-diphenylallyl)oxy)-2,3-dihydro-1H-indene (
5j) [
41]: Colorless oil. 96% yield and 93% ee, determined by chiral HPLC analysis (Chiralcel OD-H hexane/isopropanol, 99:1
v/
v, 0.5 mL/min, 25 °C, UV 254 nm), Retention times: t
r = 13.7 min for (
S)-isomer (major), t
r = 14.8 min for (
R)-isomer (minor).
1H-NMR (500 MHz, CDCl
3) δ 7.45–7.36 (m, 6H), 7.32–7.30 (m, 3H), 7.26–7.15 (m, 5H), 6.65 (d,
J = 15.9 Hz, 1H), 6.37 (dd,
J = 15.9, 7.0 Hz, 1H), 5.12 (d,
J = 6.9 Hz, 1H), 4.55–4.51 (m, 1H), 3.25–3.02 (m, 4H);
13C-NMR (125 MHz, CDCl
3) δ 141.4, 140.8, 136.5, 131.1, 130.6, 128.4, 127.5, 126.8, 126.5, 126.3, 124.5, 80.9, 77.9, 39.5.