S. Abbaraju et al. / Tetrahedron 67 (2011) 7479e7484
7483
column, i-PrOH/hexane 20:80, flow rate 0.5 mL/min at 25 ꢀC, UV
detection at 254 nm, tR (major)¼14.8 min, tR (minor)¼22.5 min.
126.0, 125.6, 120.6 (d, JCP¼4.6 Hz), 120.4 (d, JCP¼4.5 Hz), 120.1 (d,
JCP¼4.4 Hz), 118.2, 113.2, 74.6 (d, JCP¼4.1 Hz), 43.8 (d, JCP¼140.0 Hz),
30.1; nmax (neat, cmꢁ1): 3070, 3021, 2922, 2226, 1589, 1563, 1374,
1269, 1214; HRMS calcd for C21H18N2O5P (MþH)þ 409.0953; found
409.0921. HPLC conditions: Chiralpak AS column, i-PrOH/hexane
10:90, flow rate 1.0 mL/min at 25 ꢀC, UV detection at 226 nm, tR
(major)¼24.2 min, tR (minor)¼33.1 min.
4.2.2. (R)-Diphenyl 1-(4-methylphenyl)-2-nitroethylphosphonate
(3b)1b,c. White solid, yield 92%, 80% ee, 1H NMR (500 MHz, CDCl3)
d
7.33e7.29 (m, 4H; Ar), 7.19e7.16 (m, 5H; Ar), 7.12e7.08 (m, 3H; Ar),
6.78 (d, J¼8.0 Hz, 2H; Ar), 5.18 (ddd, JHP¼13.5 Hz, J1¼8.0, J2¼5 Hz,1H;
CH2), 5.09 (ddd, JHP¼17.0 Hz, J1¼11.5, J2¼7.5 Hz, 1H), 4.39 (ddd,
JHP¼24.6 Hz, J1¼11.0, J2¼4.5 Hz, 1H; CH), 2.33 (s, 3H; CH3); 13C NMR
4.2.7. (R)-Diphenyl 1-(2-methoxyphenyl)-2-nitroethylphosphonate
(125 MHz, CDCl3)
d
150.0 (d, JCP¼9.6 Hz),149.9 (d, JCP¼10.1 Hz),138.7,
(3g)1aec. White solid, yield 88%, 80% ee, 1H NMR (300 MHz,
129.9,129.6,129.0,129.02 (d, JCP¼6.7 Hz),127.4 (d, JCP¼7.7 Hz),125.6,
125.4,120.3 (d, JCP¼3.8 Hz),120.1 (d, JCP¼3.8 Hz), 75.0 (d, JCP¼5.5 Hz),
43.0 (d, JCP¼140.6 Hz), 21.0. HPLC conditions: Chiralpak AS column,
i-PrOH/hexane 10:90, flow rate 0.5 mL/min at 25 ꢀC, UV detection at
254 nm, tR (major)¼14.1 min, tR (minor)¼21.6 min.
CDCl3)
d
7.49e7.48 (td, J1¼7.6, J2¼1.8 Hz, 1H; Ar), 7.34e7.31 (m, 3H;
Ar), 7.23e7.17 (m, 3H; Ar), 7.14e7.09 (m, 3H; Ar), 7.01e6.98 (m, 1H;
Ar), 6.90 (d, J¼8.5 Hz, 1H; Ar), 6.85 (d, J¼8 Hz, 2H; Ar), 5.26e5.07
(m, 3H; CH, CH2), 3.78 (s, 3H; OCH3); 13C NMR (75 MHz, CDCl3)
d
157.6 (d, JCP¼6.7 Hz), 150.3 (d, JCP¼9.5 Hz), 150.2 (d, JCP¼9.4 Hz),
130.2 (d, JCP¼3.2 Hz), 130.0, 129.8, 129.4 (d, JCP¼5.5 Hz), 125.5 (d,
JCP¼14.4 Hz), 120.5 (d, JCP¼4.5 Hz), 120.3 (d, JCP¼4.5 Hz), 119.4 (d,
JCP¼7.6 Hz), 111.6, 74.9 (d, JCP¼4.7 Hz), 56.1, 36.5 (d, JCP¼142.8 Hz).
HPLC conditions: Chiralpak AS column, i-PrOH/hexane 10:90, flow
rate 0.5 mL/min at 25 ꢀC, UV detection at 254 nm, tR (major)¼
21.5 min, tR (minor)¼28.8 min.
4.2.3. (R)-Diphenyl 1-(4-methoxyphenyl)-2-nitroethylphosphonate
(3c)1aec. White solid, yield 89%, 80% ee, 1H NMR (300 MHz,
CDCl3) d 7.37e7.29 (m, 5H; Ar), 7.21e7.17 (m, 3H; Ar), 7.12e7.09 (m,
2H; Ar), 6.89 (d, J¼8.5 Hz, 2H; Ar), 6.78 (d, J¼7.6 Hz, 2H; Ar), 5.18
(ddd, JHP¼13.5 Hz, J1¼6.9, J2¼4.7 Hz, 1H; CH2), 5.07 (ddd,
JHP¼18.2 Hz, J1¼10.8, J2¼7.5 Hz, 1H; CH2), 4.39 (ddd, JHP¼24.5 Hz,
J1¼10.8, J2¼4.6 Hz, 1H; CH), 3.8 (s, 3H; OCH3); 13C NMR (75 MHz,
4.2.8. (R)-Diphenyl 1-(2-bromophenyl)-2-nitroethylphosphonate
CDCl3)
d
157.6 (d, JCP¼6.7 Hz), 150.4 (d, JCP¼9.6 Hz), 150.3 (d,
(3h)1a,b. White solid, yield 92%, 80% ee, 1H NMR (300 MHz, CDCl3)
JCP¼9.7 Hz), 130.2 (d, JCP¼3.2 Hz), 130.0, 129.8, 129.4 (d, JCP¼5.5 Hz),
125.6, 125.4, 121.3 (d, JCP¼2.9 Hz), 120.5 (d, JCP¼4.5 Hz), 120.2 (d,
JCP¼4.4 Hz), 119.4 (d, JCP¼7.6 Hz), 111.6, 74.8 (d, JCP¼4.6 Hz), 56.1,
36.5 (d, JCP¼142.8 Hz). HPLC conditions: Chiralpak AS column, i-
PrOH/hexane 20:80, flow rate 1.0 mL/min at 25 ꢀC, UV detection at
254 nm, tR (major)¼10.5 min, tR (minor)¼16.0 min.
d 7.63 (d, 2H; Ar), 7.35e7.30 (m, 3H; Ar), 7.19e7.07 (m, 7H; Ar), 6.78
(d, J¼8.1 Hz, 2H; Ar), 5.29e5.08 (m, 3H; CH, CH2); 13C NMR (75 MHz,
CDCl3)
d
150.1 (d, JCP¼9.5 Hz), 149.9 (d, JCP¼10 Hz), 134.0 (d,
JCP¼2.4 Hz), 130.9 (d, JCP¼7 Hz), 130.4 (d, JCP¼3.2 Hz), 130.1, 129.9,
129.3 (d, JCP¼4.5 Hz), 128.4 (d, JCP¼3.1 Hz), 126.6 (d, JCP¼9.3 Hz),
125.9, 125.6, 120.6 (d, JCP¼4.4 Hz), 120.1 (d, JCP¼4.5 Hz), 74.9 (d,
JCP¼4.9 Hz), 43.0 (d, JCP¼142.0 Hz). HPLC conditions: Chiralpak AS
column, i-PrOH/hexane 10:90, flow rate 0.5 mL/min at 25 ꢀC, UV
detection at 254 nm, tR (major)¼20.1 min, tR (minor)¼34.9 min.
4.2.4. (R)-Diphenyl 1-(4-chlorophenyl)-2-nitroethylphosphonate
(3d)1c. White solid, yield 90%, 80% ee, 1H NMR (500 MHz, CDCl3)
d
7.42e7.32 (m, 6H; Ar), 7.27e7.20 (m, 3H; Ar), 7.16e7.10 (m, 3H;
Ar), 6.81 (d, J¼9.8 Hz, 2H; Ar), 5.20 (ddd, JHP¼13.9 Hz, J1¼6.9,
J2¼4.3 Hz, 1H; CH2), 5.09 (ddd, JHP¼18.2 Hz, J1¼11.2, J2¼7.0 Hz, 1H;
CH2), 4.42 (ddd, JHP¼24.7 Hz, J1¼11.2, J2¼4.2 Hz, 1H; CH); 13C NMR
4.2.9. (R)-Diphenyl 1-(2-nitrophenyl)-2-nitroethylphosphonate
(3i)1a,b. White solid, yield 91%, 80% ee, 1H NMR (300 MHz, CDCl3)
d
7.98 (d, J¼8 Hz, 1H; Ar), 7.81 (d, J¼9.9 Hz, 1H; Ar), 7.63 (t, J¼7.4 Hz,
(125 MHz, CDCl3)
d
150.1 (d, JCP¼9.6 Hz),150.0 (d, JCP¼9.7 Hz),135.3,
1H; Ar), 7.49 (t, J¼9.3 Hz,1H; Ar), 7.33 (t, J¼7.5 Hz, 2H; Ar), 7.22e7.05
(m, 6H; Ar), 6.83 (d, J¼8.2 Hz, 2H; Ar), 5.74 (ddd, JHP¼26 Hz, J1¼10.4,
J2¼4.8 Hz, 1H; CH2), 5.26 (ddd, JHP¼14.5 Hz, J1¼6.9, J2¼4.9 Hz, 1H;
CH2), 5.17 (ddd, JHP¼17.5 Hz, J1¼10.4, J2¼7.2 Hz, 1H; CH2). 13C NMR
130.7 (d, JCP¼6.6 Hz), 130.1 (d, JCP¼27.7 Hz), 129.7, 129.5 (d,
JCP¼7.6 Hz), 125.9 (d, JCP¼25.7 Hz), 120.5 (d, JCP¼3.8 Hz), 120.3 (d,
JCP¼4.8 Hz), 75.0, 43.1 (d, JCP¼140.8 Hz). HPLC conditions: Chiralpak
AS column, i-PrOH/hexane 10:90, flow rate 0.5 mL/min at 25 ꢀC, UV
detection at 254 nm, tR (major)¼21.4 min, tR (minor)¼28.0 min.
(75 MHz, CDCl3)
d
150.1, 150.0 (d, JCP¼9.5 Hz), 149.9 (d, JCP¼9.9 Hz),
133.7, 130.2, 129.9, 129.8, 129.7, 126.6 (d, JCP¼6.7 Hz), 126.4, 125.8,
120.5 (d, JCP¼4.4 Hz),120.04 (d, JCP¼4.5 Hz) 74.7 (d, JCP¼4.4 Hz), 37.2
(d, JCP¼140.9 Hz). HPLC conditions: Chiralpak AS column, i-PrOH/
hexane 20:80, flow rate 0.5 mL/min at 25 ꢀC, UV detection at 254 nm,
tR (major)¼12.3 min, tR (minor)¼19.1 min.
4.2.5. (R)-Diphenyl 1-(4-bromophenyl)-2-nitroethylphosphonate
(3e)1aec. White solid, yield 90%, 80% ee, 1H NMR (300 MHz, CDCl3)
d
7.50 (d, J¼8.2 Hz, 2H; Ar), 7.35e7.30 (m, 4H; Ar), 7.22e7.20 (m, 3H;
Ar), 7.11e7.08 (m, 3H; Ar), 6.81 (d, J¼8.2 Hz, 2H; Ar), 5.20 (ddd,
JHP¼13.9 Hz, J1¼6.9, J2¼4.5 Hz, 1H; CH2), 5.08 (ddd, JHP¼18.0 Hz,
J1¼11.0, J2¼7.0 Hz, 1H; CH2), 4.41 (ddd, JHP¼24.6 Hz, J1¼10.8,
4.2.10. (R)-Diphenyl 1-(3-bromophenyl)-2-nitroethylphosphonate
(3j)1a. White solid, yield 90%, 77% ee, 1H NMR (300 MHz, CDCl3)
J2¼4.4 Hz,1H; CH); 13C NMR (75 MHz, CDCl3)
d
150.1 (d, JCP¼7.2 Hz),
d
7.58 (d, J¼1.7 Hz, 1H; Ar), 7.48 (d, J¼7.7 Hz, 1H; Ar), 7.39 (d,
149.9 (d, JCP¼9.7 Hz), 132.6, 131.0 (d, JCP¼6.5 Hz), 130.2, 130.0, 126.0,
125.8, 123.4, 120.5 (d, JCP¼4.4 Hz), 120.2 (d, JCP¼4.4 Hz), 74.5 (d,
JCP¼4.9 Hz), 43.2 (d, JCP¼141.1 Hz). HPLC conditions: Chiralpak AS
column, i-PrOH/hexane 10:90, flow rate 0.5 mL/min at 25 ꢀC, UV
detection at 254 nm, tR (major)¼23.5 min, tR (minor)¼31.1 min.
J¼7.6 Hz, 1H; Ar), 7.33 (t, J¼7.6 Hz, 2H; Ar), 7.26e7.09 (m, 7H; Ar),
6.8 (d, J¼7.9 Hz, 2H; Ar), 5.19 (ddd, JHP¼13.9 Hz, J1¼7.1, J2¼4.5 Hz,
1H; CH2), 5.08 (ddd, JHP¼18 Hz, J1¼10.8, J2¼7.1 Hz, 1H; CH2), 4.4
(ddd, JHP¼24.5 Hz, J1¼10.7, J2¼4.4 Hz, 1H; CH); 13C NMR (75 MHz,
CDCl3)
d
150.1 (d, JCP¼9.5 Hz), 149.9 (d, JCP¼9.9 Hz), 134.0 (d,
JCP¼2.3 Hz), 130.9 (d, JCP¼6.9 Hz), 130.4 (d, JCP¼3.1 Hz), 130.2, 129.9,
129.3 (d, JCP¼4.5 Hz), 128.4 (d, JCP¼3.1 Hz), 126.6 (d, JCP¼9.3 Hz),
125.9, 125.6, 120.6 (d, JCP¼4.4 Hz), 120.1 (d, JCP¼4.5 Hz), 74.9 (d,
JCP¼4.8 Hz), 42.0 (d, JCP¼142.0 Hz). HPLC conditions: Chiralpak AS
column, i-PrOH/hexane 20:80, flow rate 1.0 mL/min at 25 ꢀC, UV
detection at 254 nm, tR (major)¼8.3 min, tR (minor)¼16.7 min.
4.2.6. (R)-Diphenyl 1-(4-cyanophenyl)-2-nitroethylphosphonate
(3f). White solid, yield 75%, 70% ee, ½a D25
ꢂ
ꢁ6.7 (c 1.5 in CH2Cl2),
mp: 90e92 ꢀC 1H NMR (300 MHz, CDCl3):
d 7.69e7.57 (m, 4H; Ar),
7.35e7.06 (m, 9H; Ar), 6.79 (d, J¼8.4 Hz, 1H; Ar), 5.23 (ddd,
JHP¼14.1 Hz, J1¼6.9, J2¼4.4 Hz, 1H; CH2), 5.12 (ddd, JHP¼17.5 Hz,
J1¼11.0, J2¼6.5 Hz, 1H; CH2), 4.49 (ddd, JHP¼24.8 Hz, J1¼11.0,
J2¼4.4 Hz, 1H; CH); 13C NMR (75 MHz, CDCl3)
d
150.1, 149.9 (d,
4.2.11. (R)-Diphenyl 1-(1-naphthyl)-2-nitroethylphosphonate
JCP¼10.7 Hz), 149.7 (d, JCP¼9.6 Hz), 136.5, 133.0, 132.6, 130.3 (d,
JCP¼2.8 Hz), 130.2, 130.0 (d, JCP¼4.2 Hz), 128.6 (d, JCP¼5.8 Hz), 126.2,
(3k)1a,b. White solid, yield 90% 84% ee, 1H NMR (300 MHz, CDCl3)
d
8.25 (d, J¼8.5 Hz, 1H; Ar), 7.90e7.82 (m, 3H; Ar), 7.62e7.43 (m, 3H;