Radical Addition Reactions of Phosphorus Hydrides
FULL PAPER
tert-Butyl 3-Methyl-4-{[(octyloxy)(phenyl)phosphonothioyl]methyl}-
1-pyrrolidinecarboxylate (23): Colourless oil (60%). Rf = 0.4 (light
51.4 (br. m, NCH2), 49.0–48.5 (br. m, NCH2), 40.3–39.2 (br. m,
CH), 36.4–34.3 (br. m, CH), 31.4 (d, JCP = 57 Hz, PCH2), 28.3
1
petroleum/EtOAc, 4:1). IR (CH Cl ): ν = 3055 (s), 2929 (s), 2858
[C(CH3)3], 13.6 (CHCH3) ppm. MS (CI, NH3): m/z (%) = 416 (20)
˜
2
2
(s), 2361 (s), 1695 (s, C=O), 1437 (s, P–Cipso), 1110 (s) cm–1. 1H [M + H+], 316 (100), 360 (40). HRMS: found: [M + H+], 416.1811.
NMR (400 MHz, CDCl3): (major peaks): δ = 7.98–7.86 (m, 2 H, C23H31NO2PS requires 416.1813.
2×CH, aromatic), 7.55–7.45 (m, 3 H, 3×CH, aromatic), 4.12–3.99
The presence of the minor trans diastereoisomer was indicated by
(m, 2 H, OCH2), 3.69–2.73 (m, 5 H, 2×NCH2 and CHCHCH3),
1H and 13C NMR spectroscopy. 1H NMR (270 MHz, CDCl3): δ =
2.37–1.59 (m, 5 H, PCH2, CHCH3 and OCH2CH2), 1.45 [9 H, s,
1.00 (d, J = 6.5 Hz, 3 H, CHCH3) ppm. 13C NMR (67.9 MHz,
C(CH3)3], 1.42–1.19 (m, 10 H, 5×CH2), 0.86 and 0.83 (2×d, 2×J
1
CDCl3): δ = 35.0 (d, JCP = 56 Hz, PCH2), 15.2 (CHCH3) ppm.
= 7.0 Hz, 3 H, 2×CH3) ppm. 13C NMR (100 MHz, CDCl3):
1
O,O-Diethyl (4-Methyltetrahydrofuran-3-yl)methylphosphonothioate
(26): Colourless oil (19%, 2:1 cis/trans mixture of inseparable dia-
(major peaks): δ = 152.1 (CO2), 132.0 (d, JCP = 81, Cipso, aro-
matic), 130.3–126.5 (m, 5×CH, aromatic), 78.5 [OC(CH3)3], 62.8
(OCH2), 51.1, 50.2 (NCH2), 47.3, 47.0, 33.8, 30.0 (CHCH2N,
CHCH3, PCH2 and OCH2CH2), 29.2 [OC(CH3)3], 27.1, 26.5, 23.7,
20.7 (CH2), 13.3, 12.2 (CH3) ppm. 31P NMR (109.3 MHz, CDCl3):
(major peak): δ = 92.5 ppm. MS (CI, NH3): m/z (%) = 468 (28) [M
+ H+], 368 (100). HRMS: found: M + H+, 468.2704. C25H42NO3PS
requires 468.2726.
1
stereoisomers from the H NMR spectrum). Rf = 0.2 (light petro-
leum/EtOAc, 4:1). IR (CHCl ): ν = 2990 cm–1 (s), 2976 (s), 2862
˜
3
(s), 1059 (s, P–O), 1030 (s, P–O), 955 (s, P=S) cm–1. 1H NMR
(400 MHz, CDCl3): δ = (major cis isomer) 4.15–3.98 (m, 4 H,
2×POCH2CH3), 3.94 (t, J = 8.5 Hz, 1 H, OCHAHB), 3.92 (dd, J
= 8.5 and 6.0 Hz, 1 H, OCHCHD), 3.56 (t, J = 8.5 Hz, 1 H, OCHA-
HB), 3.47 (dd, J = 8.5 and 4.0 Hz, 1 H, OCHCHD), 2.65–2.53 (m,
1 H, PCH2CH), 2.35–2.25 (m, 1 H, CHCH3), 2.08–1.58 (m, 2 H,
CH2P), 1.23 (t, J = 7.0 Hz, 6 H, 2×POCH2CH3), 0.88 (d, J =
7.5 Hz, 3 H, CHCH3) ppm. 13C NMR (100.6 MHz, CDCl3): δ =
(4-Methyltetrahydrofuran-3-yl)methyl(diphenyl)phosphane Sulfide
(24): Colourless oil (59%, 2:1 cis/trans mixture of inseparable dia-
1
stereoisomers from the H NMR spectrum). Rf = 0.4 (light petro-
leum/EtOAc, 1:1). IR (CH Cl ): ν = 3050 (s), 2960 (s), 2875 (s),
˜
3
2
2
(major cis isomer) 74.7 (OCH2CHCH3), 71.5 (d, JCP = 8 Hz,
OCH2CHCH2), 62.4 (d, JCP = 7 Hz, POCH2CH3), 62.2 (d, JCP
1
1437 (s, P–Cipso), 1103 (s) cm–1. H NMR (270 MHz, CDCl3): δ =
(major cis diastereoisomer) 7.92–7.79 (m, 4 H, 4×CH, aromatic),
7.51–7.38 (m, 6 H, 6×CH, aromatic), 3.82 (dd, J = 8.0 and 6.0 Hz,
1 H, OCHH), 3.67 (dd, J = 8.0 and 7.5 Hz, 1 H, OCHH), 3.41 (dd,
J = 8.0 and 4.0 Hz, 1 H, OCHH), 3.27 (dd, J = 8.0 and 4.0 Hz, 1
H, OCHH), 2.80–2.20 (m, 4 H, PCH2, PCH2CH and CHCH3),
0.93 (d, J = 7.0 Hz, 3 H, CH3) ppm. 13C NMR (67.9 MHz, CDCl3):
2
2
2
= 7 Hz, POCH2CH3), 37.0 (d, JCP = 3 Hz, PCH2CH), 36.3 (d,
3JCP = 13 Hz, CHCH3), 33.0 (d, JCP = 112 Hz, CH2P), 2×16.1
1
3
(2×d, JCP = 7 and 7 Hz, 2×POCH2CH3), 13.3 (CHCH3) ppm.
MS (CI, NH3): m/z (%) = 253 (100) [M + H+]. HRMS: found: [M
+ H+], 253.1030. C10H22O3PS requires 253.1027.
1
The presence of the minor trans diastereoisomer was indicated by
1H and 13C NMR spectroscopy. 1H NMR (400 MHz, CDCl3): δ =
δ = (major cis diastereoisomer) 133.0 (d, JCP = 81 Hz, Cipso, aro-
1
4
matic), 132.3 (d, JCP = 80 Hz, Cipso, aromatic), 131.4 (d, JCP
=
0.98 (d, J = 6.5 Hz, 3 H, CHCH3) ppm. 13C NMR (100.6 MHz,
3 Hz, 2×CH, aromatic), 131.0–130.7 (m, 4×CH, aromatic), 128.4
3
3
3
CDCl3):
δ
=
74.3 (OCH2CHCH3), 73.6 (d, JCP
OCH2CHCH2), 41.7 (d, JCP = 4 Hz, PCH2CH), 40.8 (d, JCP
17 Hz, CHCH3), 37.2 (d, JCP
(CHCH3) ppm.
=
5 Hz,
(d, JCP = 12 Hz, 2×CH, aromatic), 128.3 (d, JCP = 12 Hz,
2
3
3
=
2×CH, aromatic), 74.2 (OCH2CHCH3), 71.1 (d, JCP = 5 Hz,
OCH2CHCH2), 36.7 (d, JCP = 2 Hz, PCH2CH), 36.6 (d, JCP
8 Hz, CHCH3), 30.8 (d, JCP = 57 Hz, PCH2), 13.3 (CH3) ppm.
MS (CI, NH3): m/z (%) = 317 (100) [M + H+], 100%). HRMS:
found: [M + H+], 317.1120. C18H22OPS requires 317.1129.
1
2
3
=
113 Hz, PCH2), 15.6
=
1
Typical Procedure for the HWE-type Reaction: Synthesis of 3-(2,2-
Diphenylvinyl)-4-methyltetrahydrofuran (27) From O-Octyl (4-
Methyltetrahydrofuran-3-yl)methyl(phenyl)phosphinothioate (22): To
a stirred solution of the phosphinothioate 22 (0.130 g, 0.35 mmol)
(as a 3.7:3.7:1:1 mixture of diastereoisomers from the 1H NMR
spectrum) in dry THF (4 cm3) at –78 °C under nitrogen was added
a 1.23 solution of sBuLi in THF (0.57 cm3, 0.71 mmol) dropwise.
The solution was warmed to –20 °C within 0.75 h and then cooled
to –78 °C. A THF solution (2 cm3) of benzophenone (0.129 g,
0.71 mmol) was added. The solution was warmed to room temp.
and then stirred for 12 h. Water (50 cm3) and EtOAc (50 cm3) were
added to the crude mixture, the layers were separated and the aque-
ous layer was extracted with EtOAc (2×50 cm3). The organic layer
was dried (MgSO4), filtered and concentrated in vacuo. Purification
with column chromatography (silica; light petroleum/EtOAc, 9:1)
afforded the tetrahydrofuran 27 (0.057 g, 72%) as a colourless oil,
The presence of the minor trans diastereoisomer was indicated by
1H and 13C NMR spectroscopy. 1H NMR (270 MHz, CDCl3): δ =
3.89 (t, J = 7.8 Hz, 1 H, OCHH), 3.66 (dd, J = 8.0 and 7.5 Hz, 1
H, OCHH), 3.22 (dd, J = 8.0 and 8.5 Hz, 1 H, OCHH), 3.20 (t, J
= 8.0 Hz, 1 H, OCHH), 0.96 (d, J = 6.5 Hz, 3 H, CH3) ppm. 13C
1
NMR (67.9 MHz, CDCl3): δ = 132.8 (d, JCP = 80 Hz, Cipso, aro-
1
matic), 132.6 (d, JCP
=
80 Hz, Cipso
,
aromatic), 73.7
(OCH2CHCH3), 73.2 (d, 3JCP = 3 Hz, OCH2CHCH2), 41.2 (d, 2JCP
= 2 Hz, PCH2CH), 41.1 (d, JCP = 13 Hz, CHCH3), 35.4 (d, JCP
= 57 Hz, PCH2), 15.3 (CH3) ppm.
3
1
tert-Butyl 3-[(Diphenylphosphinothioyl)methyl]-4-methyl-1-pyrroli-
dinecarboxylate (25): Colourless oil (70%, 1.9:1 cis/trans mixture of
inseparable diastereoisomers from the 1H NMR spectrum). Rf =
0.5 (light petroleum/EtOAc, 1:1). IR (CH Cl ): ν = 2975 (s), 2932
as a 3.7:1 cis/trans mixture of inseparable diastereoisomers from
˜
2
2
(s), 1685 (s, C=O), 1409 (s, P–Cipso), 1103 (w) cm–1. 1H NMR the H NMR spectrum. Rf = 0.3 (light petroleum/EtOAc, 9:1). IR
1
(270 MHz, CDCl3): δ = (major cis diastereoisomer, mixture of con- (CDCl ): ν = 3059 (s), 3023 (s), 2964 (s), 2869 (s), 1657 (m, C=C)
˜
3
formers) 7.95–7.78 (m, 4 H, 4×CH, aromatic), 7.55–7.40 (m, 6 H,
6×CH, aromatic), 3.60–2.70 (m, 4 H, 2×NCH2), 2.60–2.10 (m, 4
H, PCH2, PCH2CH and CHCH3), 1.36 [br. s, 9 H, C(CH3)3], 0.90
(d, J = 7.0 Hz, 3 H, CH3) ppm. 13C NMR (67.9 MHz, CDCl3): δ
= (major cis diastereoisomer, mixture of conformers) 154.3, 153.9
cm–1. 1H NMR (270 MHz, CDCl3): δ = (major cis diastereoisomer)
7.40–7.15 (m, 5 H, 5×CH, aromatic), 6.04 (d, J = 10.5 Hz, 1 H,
C=CH), 3.92 (dd, J = 7.5 and 8.0 Hz, 1 H, OCHCHD), 3.89 (dd, J
= 6.5 and 8.0 Hz, 1 H, OCHAHB), 3.69 (dd, J = 8.0 and 6.5 Hz, 1
H, OCHAHB), 3.53 (dd, J = 8.0 and 5.5 Hz, 1 H, OCHCHD), 2.97
(dq, J = 10.5 and 6.5 Hz, 1 H, OCH2CHCH), 2.35–2.26 (m, 1 H,
1
[NC(O)O], 133.0 (br. d, JCP = 81 Hz, 2 × Cipso, aromatic), 131.7–
131.0 (m, 2×CH, aromatic), 130.8–130.5 (m, 4×CH, aromatic), OCH2CHCH3), 1.08 (d, J = 7.0 Hz, 3 H, CHCH3) ppm. 13C NMR
128.7–128.3 (m, 4×CH, aromatic), 78.8, 78.7 [OC(CH3)3], 52.5–
(67.9 MHz, CDCl3): δ = (major cis diastereoisomer) 143.7 (Cipso
,
Eur. J. Org. Chem. 2006, 1547–1554
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1553