Photochemical behaviors of tetraphenyldiphosphine in the presence of alkynes

Article abstract of DOI:10.1016/j.tetlet.2006.03.165

Under an atmosphere of nitrogen, the photoinduced reaction of tetraphenyldiphosphine (1) with alkynes (2) generates vicinal bisphosphinated alkenes (3) as air-sensitive compounds, which can be isolated by treatment with elemental sulfur. A novel E to Z isomerization of 3 is revealed to take place upon continuous photoirradiation.

Full text of DOI:10.1016/j.tetlet.2006.03.165

Tetrahedron Letters 47 (2006) 3919–3922
Photochemical behaviors of tetraphenyldiphosphine in the
presence of alkynes
Shin-ichi Kawaguchi, Shoko Nagata, Takamune Shirai, Kaname Tsuchii,
Akihiro Nomoto and Akiya Ogawa*
Department of Applied Chemistry, Faculty of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku Sakai,
Osaka 599-8531, Japan
Received 6 February 2006; revised 16 March 2006; accepted 24 March 2006
Available online 24 April 2006
Abstract—Under an atmosphere of nitrogen, the photoinduced reaction of tetraphenyldiphosphine (1) with alkynes (2) generates
vicinal bisphosphinated alkenes (3) as air-sensitive compounds, which can be isolated by treatment with elemental sulfur. A novel
E to Z isomerization of 3 is revealed to take place upon continuous photoirradiation.
Ó 2006 Elsevier Ltd. All rights reserved.
Radical addition of heteroatom compounds to carbon–
carbon unsaturated bonds based on the photoinduced
homolytic cleavage of heteroatom–heteroatom single
bonds is one of the most useful and highly atom-eco-
nomical methods for selective introduction of hetero-
atom functions into organic molecules.1 Recently, we
have disclosed novel photoinduced bisselenation2 and
bistelluration3 of alkynes with organic diselenides and
ditellurides, which provide a useful tool to vicinal bis-
seleno- and bistelluroalkenes, respectively (Eqs. 1 and 2).
sensitive, generating immediately several oxidation
products, which can be assigned unambiguously by
31
measurement of their P NMR spectra.7 The use of
degassed solvent is effective for depressing the undesir-
able air-oxidation of diphosphine 1 (ca. 70% of 1 is
survived by this treatment, see Chart 17,8), and makes
it possible to study the reactions of 1.
Tetraphenyldiphosphine (1) exhibits its absorption maxi-
mum in 260 nm (e = 41.3), and its absorption reaches to
330 nm.9 Therefore, the irradiation with the light of the
wavelength in these regions (e.g., near-UV light irradia-
tion) induces the homolytic cleavage of the P–P single
R
SePh
h
ν
(PhSe)2
(PhTe)2
ð1Þ
ð2Þ
R
R
+
+
PhSe
R
TePh
h
ν
PhTe
However, similar transformations concerning group 15
heteroatom compounds have been largely unexplored.4,5
In this letter, we wish to report detailed experiments,
which have been done to develop the photoinduced bis-
phosphination of alkynes by using tetraphenyldiphos-
phine as the representative heteroatom compounds
bearing a group 15 heteroatom–heteroatom linkage.6
Tetraphenyldiphosphine (Ph2P–PPh2, 1)5 is a commer-
cially available white solid (mp 120–122 °C) and is stable
in the solid state. However, in solvent, 1 is extremely air-
*
Corresponding author. Tel./fax: +81 72 254 9290; e-mail: ogawa@
chem.osakafu-u.ac.jp
0040-4039/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetlet.2006.03.165
Chart 1. 31P NMR spectrum of (Ph2P)2 in degassed CDCl3.

3920
S. Kawaguchi et al. / Tetrahedron Letters 47 (2006) 3919–3922
bond of 1 to generate the corresponding phosphorus-
centered radical as a label species.10,11 However, both
the extremely high air-sensitivity of 1 and its lower
solubility in organic solvents may contribute to the
difficulty in realizing the radical addition of 1 to car-
bon–carbon unsaturated compounds.
phinylation product (4a). The yield of 3a increased with
the reaction times. On the other hand, the hydrophos-
phinylation product (4a) was formed within 4 h, most
probably by the reaction of 2a with initially formed
diphenylphosphine oxide (Ph2P(O)H).12
Noteworthy is that isomerization from (E)-3a to (Z)-3a
was observed to take place gradually: After the irradia-
tion for 39 h, (Z)-3a was obtained mainly (E/Z = 18/
82). These results clearly indicate that the present photo-
induced bisphosphination is promising as a useful tool
to (Z)-isomers of vic-bis(diphenylphosphino)alkenes.
The stereochemistry of 3a can be easily determined by
measurement of 31P NMR: The coupling constant for
(E)-3a (JP–P = 340 Hz) is larger than that of (Z)-isomer
(JP–P = 161 Hz).
To accomplish the desired radical addition of diphos-
phine 1 to terminal alkynes, the reaction was conducted
in an NMR tube sealed carefully under nitrogen atmo-
sphere by using degassed solvent. In an NMR tube
(/ = 4 mm, Pyrex) filled with nitrogen, were placed
tetraphenyldiphosphine (0.132 mmol, stored in Schlenck
tube under nitrogen), 5-methyl-1-hexyne (2a, 0.044
mmol), and CD2Cl2 (0.6 mL, degassed), and then the
tube was sealed. Irradiation with a xenon lamp
(500 W) was conducted at room temperature, and the
1
reaction was monitored by H and 31P NMR using tri-
Similar conditions can be employed with 1-octyne (2b)
and 5-chloro-1-pentyne (2c) (Table 1, entries 2–3). In
these cases, the Z selectivity in the bisphosphination also
increased with the prolonged photoirradiation. On the
other hand, the bisphosphination of phenylacetylene
proceeded very smoothly and provided only (Z)-isomer
selectively (entry 4).13
1
phenylmethane as an internal standard for H NMR.
h
ν
(>300 nm)
(Ph2P)2
+
r.t., CD2Cl2
2a
O
PPh2
Isolation of the bisphosphination product 3 was
attempted by using preparative HPLC. However, the
desired isolation of 3 failed, owing to the instability of
3 toward air. Thus, this letter deals with only spectral
analyses of the bisphosphination products.14 Since the
direct isolation of the bisphosphination product 3 is very
difficult, the isolation was examined by the treatment of
the bisphosphination product 3 with elemental sulfur.
Purification by preparative TLC provided 5 in good
yields, as shown in Table 115.
+
Ph2P
PPh2
H
ð3Þ
3a
4a
21% [E/Z = 81/19]
37% [E/Z = 73/27]
51% [E/Z = 29/71]
63% [E/Z = 24/76]
62% [E/Z = 18/82]
13% [E/Z = 38/62]
23% [E/Z = 39/61]
24% [E/Z = 37/63]
28% [E/Z = 43/57]
31% [E/Z = 55/45]
2 h
4 h
20 h
27 h
39 h
As can be seen from Eq. 3, the photoinduced reaction of
diphosphine 1 with 5-methyl-1-hexyne (2a) provided the
corresponding bisphosphination product (3a) as the
major product, along with small amounts of hydrophos-
A possible reaction pathway for the formation of bis-
phosphination product 3 is as follows (Scheme 1). Upon
irradiation with near-UV light, tetraphenyldiphosphine
Table 1. Photoinduced bisphosphination of alkynes
hν
R
R
S8
(Ph2P)2
R
+
r.t.
Ph2P
PPh2
Ph2P
PPh2
S
S
2
3
5
Entry
Alkyne
Solv.
Time (h)
Yield (%) [E/Z]a
3
5
1
2
3
4
CD2Cl2
C6D6
39
26
18
1
62 [18/82]
54 [23/77]
2a
nHex
68 [35/65]
55 [42/58]
45 [0/100]
53 [34/66]
53 [53/47]
46 [50/50]
2b
2c
Cl(CH2)3
Ph
CD2Cl2
CD2Cl2
2d
a One unidentified product (R–CH2@CH–P(O)Ph2, 4) was also obtained as byproduct: 31% [E/Z = 55/45] (4a, entry 1); 24% [E/Z = 50/50] (4b, entry
2); 18% [E/Z = 67/33] (4c, entry 3); 8% [E/Z = 25/75] (4d, entry 4).

S. Kawaguchi et al. / Tetrahedron Letters 47 (2006) 3919–3922
3921
(k) Toru, T.; Seko, T.; Maekawa, E.; Ueno, Y. J. Chem.
Soc., Perkin Trans. 1 1988, 575; (l) Toru, T.; Seko, T.;
Maekawa, E.; Ueno, Y. J. Chem. Soc., Perkin Trans. 1
1989, 1927; (m) Back, T. G.; Brunner, K.; Krishna, M. V.;
Lai, E. K. Y.; Muralidharan, K. R. In Heteroatom
Chemistry; Block, E., Ed.; VCH: New York, 1990,
Chapter 4; (n) Kang, Y.-H.; Kice, J. L. J. Org. Chem.
1984, 49, 1507; (o) Back, T. G.; Muralidharan, K. R.
J. Org. Chem. 1989, 54, 121; (p) Back, T. G. Phosphorous
Sulfur, Silicon, Relat. Elem. 1992, 67, 203.
R
PPh2
hν
R
(Ph2P)2
Ph2P
1
6
3
(Ph2P)2
- Ph2P
PPh2
R
Ph2P
2. (a) Back, T. G.; Krishna, M. V. J. Org. Chem. 1988, 53,
2533; (b) Ogawa, A.; Yokoyama, K.; Yokoyama, H.;
Sekiguchi, M.; Kambe, N.; Sonoda, N. Tetrahedron Lett.
1990, 31, 5931; (c) Ogawa, A.; Yokoyama, H.; Yokoyama,
K.; Masawaki, T.; Kambe, N.; Sonoda, N. J. Org. Chem.
1991, 56, 5721; (d) Ogawa, A.; Takami, N.; Sekiguchi, M.;
Yokoyama, H.; Kuniyasu, H.; Ryu, I.; Sonoda, N. Chem.
Lett. 1991, 2241; (e) Ogawa, A.; Doi, M.; Ogawa, I.;
Hirao, T. Angew. Chem., Int. Ed. 1999, 38, 2027; (f)
Ogawa, A.; Doi, M.; Tsuchii, K.; Hirao, T. Tetrahedron
Lett. 2001, 42, 2317; (g) Ogawa, A.; Ogawa, I.; Sonoda, N.
J. Org. Chem. 2000, 65, 7682; (h) Tsuchii, K.; Doi, M.;
Ogawa, I.; Einaga, Y.; Ogawa, A. Bull. Chem. Soc. Jpn.
2005, 78, 1534.
3. (a) Ogawa, A.; Yokoyama, K.; Yokoyama, H.; Obayashi,
R.; Kambe, N.; Sonoda, N. J. Chem. Soc., Chem.
Commun. 1991, 1748; (b) Ogawa, A.; Yokoyama, K.;
Obayashi, R.; Han, L.-B.; Kambe, N.; Sonoda, N.
Tetrahedron 1993, 49, 1177.
4. (a) Kuchen, W.; Buchwald, H. Chem. Ber. 1958, 91, 2871;
(b) Tzschach, V. A.; Baensch, S. J. Prakt. Chem. 1971,
313, 254; (c) Wong, S. K.; Sytnyk, W.; Wan, J. K. S. Can.
J. Chem. 1971, 49, 994; (d) Davidson, R. S.; Sheldon, R.
A.; Trippert, S. J. Chem. Soc. 1966, 722; (e) Hewertson,
W.; Taylor, I. C. J. Chem. Soc. 1970, 1990.
Scheme 1. A possible pathway for bisphosphination.
1 undergoes homolytic dissociation to generate Ph2PÅ,
which attacks the terminal carbon of terminal alkynes
to give the corresponding b-diphenylphosphino-substi-
tuted vinylic radical (6). The subsequent SH2 reaction
between the vinylic radical and the diphosphine 1 pro-
vides the bisphosphination product 3.
On the other hand, the formation of 4 can be explained
by the addition to terminal alkynes, of diphenylphos-
phine oxide, which is formed at the initial stage from
(Ph2P)2 and water (contaminated). This was strongly
supported by the fact that the reaction of (Ph2P)2 with
D2O led to the formation of Ph2PD and Ph2P(O)D
upon photoirradiation.16 Furthermore, the formation
of diphenylphosphine oxide was clearly accel-
erated in the presence of terminal alkynes, and this
fact suggests that acetylenic proton can also be
employed as a proton source for diphenylphosphine
oxide.
5. Very recently, V-40-initiated bisphosphination of alkynes
with tetraphenyldiphosphine (formed in situ from Ph2PH
and Ph2PCl) is reported, which selectively provides trans-
isomers of vicinal bis(diphenylthiophosphanyl)alkenes
after treatment with elemental sulfur: Sato, A.; Yorimitsu,
H.; Oshima, K. Angew. Chem., Int. Ed. 2005, 44, 1694.
6. Our preliminary results of this photoinduced bispho-
sphination were presented at the 1st Pacific Symposium on
Radical Chemistry (PSRC-1, November 15, 2004, Kana-
zawa, Japan).
In summary, we have disclosed the reactivity of tetra-
phenyldiphosphine upon photoirradiation conditions.
Detailed mechanism of hydrophosphination and its syn-
thetic utility are now under investigation.
Acknowledgment
7. For 31P NMR of 1 (Ph2P)2: d ꢀ14.27 ppm, see: (a) Koster,
R.; Schubler, W.; Synoradzki, L. Chem. Ber. 1987, 120,
1105; (b) Bohm, V. P. W.; Brookhart, M. Angew. Chem.,
Int. Ed. 2001, 40, 4694; For 31P NMR of Ph2PP(O)Ph2: d
ꢀ23.12, 34.57 ppm, see: Irvine, D. J.; Glidewell, C.; Cole-
Hamilton, D. J.; Barnes, J. C.; Howie, A. J. Chem. Soc.,
Dalton Trans. 1991, 1765; For 31P NMR of Ph2P(O)-
P(O)Ph2: d 21.87 ppm, see: Zhao, N.; Neckers, D. C.
J. Org. Chem. 2000, 65, 2145; For 31P NMR of
Ph2P(O)OP(O)Ph2: d 26.04 ppm, see: Korth, H. G. J.
Org. Chem. 1990, 55, 624; For 31P NMR of Ph2P(O)H: d
17.99 ppm, see: Dabkowski, W.; Michalski, J.;
Skrzypczynski, Z. J. Chem. Soc., Chem. Commun. 1982,
1260; For 31P NMR of Ph2P(O)OH: d 31.45 ppm, see:
Lukes, I.; Borbaruah, M.; Quin, L. D. J. Am. Chem. Soc.
1994, 116, 1737.
We gratefully acknowledge Professor L.-B. Han (Na-
tional Institute of Advanced Industrial Science and
Technology (AIST)) for his useful suggestions.
References and notes
1. (a) Ogawa, A. In Main Group Metals in Organic Synthesis;
Yamamoto, H., Oshima, K., Eds.; Wiley-VCH:
Weinheim, 2004; Vol. 2, p 813; (b) Ogawa, A.; Hirao, T.
Rev. Heteroat. Chem. 1998, 18, 1; (c) Heiba, E. I.; Dessau,
R. M. J. Org. Chem. 1967, 32, 3837; (d) Ogawa, A.;
Tanaka, H.; Yokoyama, H.; Obayashi, R.; Yokoyama,
K.; Sonoda, N. J. Org. Chem. 1992, 57, 111; (e) Ogawa,
A.; Obayashi, R.; Ine, H.; Tsuboi, Y.; Sonoda, N.; Hirao,
T. J. Org. Chem. 1998, 63, 881; (f) Ogawa, A.; Obayashi,
R.; Sonoda, N.; Hirao, T. Tetrahedron Lett. 1998, 39,
1577; (g) Ogawa, A.; Obayashi, R.; Doi, M.; Sonoda, N.;
Hirao, T. J. Org. Chem. 1998, 63, 4277; (h) Ogawa, A.;
Ogawa, I.; Obayashi, R.; Umezu, K.; Doi, M.; Hirao, T. J.
Org. Chem. 1999, 63, 86; (i) Toru, T.; Seko, T.; Maekawa,
E. Tetrahedron Lett. 1985, 26, 3263; (j) Toru, T.; Kane-
fusa, T.; Maekawa, E. Tetrahedron Lett. 1986, 27, 1583;
8. Integral condition: Relaxation delay is 1 [s], acquisition time
is 0.2312 [s]. Ratio of integral value is (Ph2P)2:Ph2PP(O)-
Ph2:Ph2P(O)P(O)Ph2:Ph2P(O)OP(O)Ph2:Ph2P(O)H = 70:8:5:
7:10.
9. Troy, D.; Turpin, R.; Voigt, D. Bull. Soc. Chim. Fr. 1979,
241.
10. Davidson, R. S.; Sheldon, R. A.; Trippett, S. J. Chem.
Soc., (C). 1966, 722.

3922
S. Kawaguchi et al. / Tetrahedron Letters 47 (2006) 3919–3922
11. In CDCl3, diphosphine 1 was gradually decomposed to
form chlorodiphenylphosphine (Ph2PCl; 31P NMR d 82.38
ppm; Appel, R.; Milker, R. Chem. Ber. 1975, 108, 1783.)
upon irradiation through Pyrex with a xenon lamp,
whereas no conversion of 1 to Ph2PCl was observed in
CD2Cl2 and benzene. Thus, CD2Cl2 and benzene are
suitable solvents for the reactions conducted under photo-
irradiation conditions.
12. Semenzin, D.; Etemad-mogha, G.; Albouy, D.; Diallo, O.;
Koenig, M. J. Org. Chem. 1997, 62, 2414.
13. The exclusive Z selectivity observed in the bisphosphin-
ation of phenylacetylene may arise from the interaction
between the alkyne and diphosphine in the ground or
excited state.
IR (NaC1, neat) 2925, 1436, 1098, 693, 643 cmꢀ1; HRMS
calcd for C32H34P2S2: 544.1577, found: 544.1573; Anal.
Calcd for C32H34P2S2: C, 70.56; H, 6.29%. Found: C,
1
70.36; H, 6.27%. [(E)-isomer] H NMR (CDCl3) d 0.71 (t,
J = 7.3 Hz, 3H), 0.81–0.82 (m, 4H), 0.88–0.90 (m, 2H),
0.96–1.00 (m, 2H), 2.67–2.75 (m, 2H), 7.24 (dd, J = 27.1,
20.0 Hz, 1H), 7.39–7.50 (m, 10H), 7.51–7.53 (m, 2H),
7.75–7.81 (m, 8H); 13C NMR (CDC13) d 13.77, 13.87,
22.15, 29.20, 29.30, 30.85, 128.53 (d, J = 14.4 Hz), 128.64
(d, J = 14.4 Hz), 130.92, 130.96 (d, J = 10.6 Hz), 131.19
(d, J = 83.4 Hz), 132.12 (d, J = 10.6 Hz), 132.23, 133.66
(d, J = 85.4 Hz), 135.93 (ddd, J = 72.9, 19.2, 8.6 Hz),
156.38 (d, J = 59.5 Hz); 31P NMR (CDC13) d 28.66 (d,
J = 56.7 Hz), 49.58 (d, J = 61.0 Hz); IR (NaCl, neat)
14. 31P NMR (CD2Cl2), 3a: For (E)-isomer, d ꢀ30.1 ppm (d,
J = 418 Hz), ꢀ14.35 ppm (d, J = 426 Hz); For (Z)-isomer,
d ꢀ25.20 ppm (d, J = 161 Hz), ꢀ6.02 ppm (d, J =
157 Hz). Compound 3b: For (E)-isomer, d ꢀ29.85 ppm
(d, J = 300 Hz), ꢀ13.55 ppm (d, J = 300 Hz); For (Z)-
isomer, d ꢀ24.50 ppm (d, J = 157 Hz), ꢀ5.90 ppm (d, J =
161 Hz). Compound 3c: For (E)-isomer, d ꢀ30.3 ppm (d,
J = 444 Hz), ꢀ14.35 ppm (d, J = 422 Hz); For (Z)-isomer,
d ꢀ24.80 ppm (d, J = 161 Hz), ꢀ6.75 ppm (d, J =
157 Hz). Compound 3d: d ꢀ24.55 ppm (d, J = 144 Hz),
ꢀ3.51 ppm (d, J = 144 Hz).
3054, 2926, 2854, 1435, 1100, 717, 692, 629, 614, 527 cmꢀ1
.
Compound 5c: [(Z)-isomer] 1H NMR (CDCl3) d 2.02–2.07
(m, 2H), 2.54–2.60 (m, 2H), 3.45 (t, J = 6.5 Hz, 2H), 7.00
(dd, J = 41.1, 12.8 Hz, 1H), 7.23–7.27 (m, 4H), 7.29–7.33
(m, 4H), 7.35–7.39 (m, 4H), 7.64–7.69 (m, 4H), 7.73–7.78
(m, 4H); 13C NMR (CDC13) d 33.67, 37.47 (t like,
J = 5.8 Hz), 43.84, 128.4 (d, J = 11.5 Hz), 128.5 (d, J =
11.5 Hz), 130.91 (d, J = 83.5 Hz), 131.02 (d, J = 15.4 Hz),
131.02 (d, J = 4.6 Hz), 132.36 (d, J = 15.4 Hz), 132.37 (d,
J = 6.7 Hz), 133.37 (d, J = 87.5 Hz), 136.10 (ddd,
J = 79.6, 10.6, 6.7 Hz), 150.47 (d, J = 69.2 Hz); 31P
NMR (CDC13) d 31.62 (d, J = 17.4 Hz), 42.13 (d, J =
17.4 Hz); IR (NaCl, neat) 3053, 1436, 1100, 910, 799, 692,
671, 613 cmꢀ1; HRMS calcd for C29H27ClP2S2: 536.0718,
found: 536.0714. Anal. Calcd for C29H27ClP2S2: C, 64.86;
H, 5.07%. Found: C, 63.99; H, 5.09%. [(E)-isomer] 1H
NMR (CDC13) d 1.43–1.49 (m, 2H), 2.83–2.93 (m, 2H),
3.11 (t,J = 6.7 Hz, 2H), 7.33 (dd, J = 25.4, 6.4 Hz, 1H),
7.42–7.50 (m, 10H), 7.53–7.56 (m, 2H), 7.74–7.80 (m, 8H);
13C NMR (CDC13) d 28.16 (t, J = 8.6 Hz), 31.97, 44.37 (t,
J = 7.7 Hz), 128.83 (d, J = 12.5 Hz), 128.86 (d, J =
12.5 Hz), 130.78 (d, J = 83.4 Hz), 130.98 (d, J = 10.5
Hz), 131.79, 132.12, 132.22 (d, J = 7.7 Hz), 133.44 (d,
J = 85.4 Hz), 137.14 (dt, J = 71.9, 8.6 Hz), 154.88 (d,
J = 60.4 Hz); 31P NMR (CDC13) d 28.42 (d, J = 56.7 Hz),
49.57 (d, J = 56.7 Hz); IR (NaCl, neat) 3053, 2330, 1437,
1099, 716, 691, 631, 613, 525, 496 cmꢀ1. Compound 5d:
[(Z)-isomer] 1H NMR (CDCl3) d 7.10 (dd, J = 26.1,
12.4 Hz, 1H), 7.06–7.40 (m, 17H), 7.61–7.78 (m, 8H); 13C
NMR (CDC13) d 127.96, 128.04, 128.19 (d, J = 11.5 Hz),
130.92 (d, J = 7.7 Hz), 131.11 (d, J = 3.0 Hz), 131.57 (d,
J = 15.3 Hz), 131.57 (d, J = 5.7 Hz), 131.76 (d, J = 85.4
Hz), 131.95 (d, J = 17.2 Hz), 131.95 (d, J = 3.8 Hz),
132.69 (d, J = 87.3 Hz), 138.98 (ddd, J = 74.8, 11.5,
10.5 Hz), 141.89 (dd, J = 16.3, 10.5 Hz), 150.78 (d, J =
69.0 Hz); 31P NMR (CDCl3) d 32.74 (d, J = 13.0 Hz),
38.38 (d, J = 13.0 Hz); IR (neat) 3053, 1436, 1097, 738,
717, 694, 644, 516 cmꢀ1; HRMS calcd for C32H26P2S2:
536.0951, found: 536.0955. Anal. Calcd for C32H26P2S2:
C, 71.62; H, 4.88%. Found: C, 71.86; H, 5.12%.
1
15. Compound 5a: [(Z)-isomer] H NMR (CDCl3) d 0.70 (d,
J = 6.4 Hz, 6H), 1.19–1.47 (m, 3H), 2.34–2.39 (m, 2H),
6.96 (dd, J = 41.7, 12.4 Hz, 1H), 7.24–7.76 (m, 20H); 13C
NMR (CDCl3) d 22.18, 27.86, 37.82, 39.75, 128.22, 128.32,
131.27 (d, J = 17.2 Hz), 131.27 (d, J = 4.7 Hz), 131.34 (d,
J = 83.7 Hz), 132.37 (d, J = 16.3 Hz), 132.37 (d, J =
5.7 Hz), 133.59 (d, J = 87.3 Hz), 134.88 (ddd, J = 82.5,
12.5, 11.5 Hz), 152.46 (d, J = 65.2 Hz); 31P NMR (CDCl3)
d 32.11 (d, J = 17.4 Hz), 42.28 (d, J = 17.4 Hz); IR (NaCl,
neat) 2952, 1436, 1097, 705, 692, 642 cmꢀ1; HRMS calcd
for C31H32P2S2: 530.1421, found: 530.1418; Anal. Calcd
for C31H32P2S2: C, 70.16; H, 6.08%. Found: C, 69.96; H,
6.04%. [(E)-isomer] 1H NMR (CDCl3)
d 0.46 (d,
J = 5.0 Hz, 6H), 0.99–1.07 (m, 2H), 1.19–1.22 (m, 1H),
2.69–2.73 (m, 2H), 7.34 (dd, J = 27.0, 20.2 Hz, 1H), 7.40–
7.84 (m, 20H); 13C NMR (CDCl3) d 21.75, 28.37, 29.05,
37.56, 128.62 (d, J = 9.5 Hz), 128.70 (d, J = 9.5 Hz),
131.04 (d, J = 7.6 Hz), 131.34 (d, J = 83.4 Hz), 131.54,
131.87, 132.26 (d, J = 9.5 Hz), 133.73 (d, J = 85.4 Hz),
136.36 (dt, J = 72.9, 9.6 Hz), 156.71 (d, J = 60.4 Hz); 31P
NMR (CDCl3)
d 28.60 (d, J = 61.0 Hz), 49.55 (d,
J = 61.0 Hz); IR (NaCl, neat) 2954, 2358, 2341, 1436,
1099, 715, 692 cmꢀ1; 5b: [(Z)-isomer] 1H NMR (CDCl3) d
0.80 (t, J = 7.3 Hz, 3H), 1.21–1.23 (m, 6H), 1.54–1.60 (m,
2H), 2.34–2.41 (m, 2H), 6.94 (dd, J = 41.7, 12.7 Hz, 1H),
7.22–7.32 (m, 8H), 7.33–7.38 (m, 4H), 7.66–7.77 (m, 8H);
13C NMR (CDC13) d 13.88, 22.37, 28.67, 30.57, 31.23,
39.65, 128.09 (d, J = 12.5 Hz), 128.32 (d, J = 12.5 Hz),
131.12 (d, J = 16.3 Hz), 131.12 (d, J = 4.8 Hz), 131.26 (d,
J = 83.5 Hz), 132.28 (d, J = 15.6 Hz), 132.28 (d,
J = 5.7 Hz), 133.59 (d, J = 86.3 Hz), 134.65 (ddd, J =
81.5, 9.6, 7.7 Hz), 152.20 (d, J = 68.1 Hz);31P NMR
(CDC13) d 31.90 (d, J = 17.4 Hz), 42.28 (d, J = 17.4 Hz);
16. (a) Yasui, S.; Shioji, K.; Yoshihara, M.; Maeshita, T.;
Ohno, A. Bull. Chem. Soc. Jpn. 1993, 66, 2077; (b) Renard,
P.-Y.; Vayron, P.; Leclerc, E.; Valleix, A.; Miskowski, C.
Angew. Chem., Int. Ed. 2003, 42, 2389.