Reaction of phosphine with allylbenzene in the KOH-DMSO system: Regioselective synthesis of (1-phenylprop-2-yl)phosphine and bis(1-phenylprop-2-yl)phosphine

Article abstract of DOI:10.1016/j.mencom.2010.09.012

Phosphine reacts with allylbenzene in the KOH-DMSO system (90-110 °C, 2-2.5 h, atmospheric pressure) to afford Markovnikov adducts, (1-phenylprop-2-yl)phosphine and/or bis(1-phenylprop-2-yl)phosphine in 53-80% yields.

Full text of DOI:10.1016/j.mencom.2010.09.012

Mendeleev
Communications
Mendeleev Commun., 2010, 20, 275–276
Reaction of phosphine with allylbenzene in the KOH–DMSO system:
regioselective synthesis of (1-phenylprop-2-yl)phosphine
and bis(1-phenylprop-2-yl)phosphine
Nina K. Gusarova, Svetlana F. Malysheva, Alexander V. Artem’ev,
Nataliya A. Belogorlova, Alexander I. Albanov and Boris A. Trofimov*
A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences,
664033 Irkutsk, Russian Federation. Fax: +7 3952 41 9346; e-mail: boris_trofimov@irioch.irk.ru
DOI: 10.1016/j.mencom.2010.09.012
Phosphine reacts with allylbenzene in the KOH–DMSO system (90–110 °C, 2–2.5 h, atmospheric pressure) to afford Markovnikov
adducts, (1-phenylprop-2-yl)phosphine and/or bis(1-phenylprop-2-yl)phosphine in 53–80% yields.
Reactions of phosphine, PH3, with allylic compounds are scarcely
documented. Radical addition of phosphine (UV-irradiation or
AIBN, 80 °C, high pressure) to allyl alcohol or allylamine gave
a mixture of the corresponding primary, secondary and tertiary
phosphines of anti-Markovnikov pattern.1 The literature lacks
the data on the addition of phosphine to allylic compounds
under basic conditions, though vinyl(het)arenes do add phos-
phine under superbasic conditions.2
and 2 are colourless oils, stable at ambient temperature under
inert atmosphere and well soluble in organic solvents.
In the absence of KOH no reaction occurs. This fact con-
firms base-catalyzed mechanism of the process, which can be
outlined by Scheme 2. In the first stage, due to [1,3H] iso-
merization of allylbenzene under the action of the superbase,
1-phenylprop-1-ene A is generated. The latter reacts with PH3
†
The 1H, 13C and 31P NMR spectra were measured on a Bruker DPX 400
Here, we report on the base-catalyzed addition of phosphine
to allylbenzene.
(400.13, 100.61 and 161.98 MHz, respectively) spectrometer. IR spectra
were recorded on a Bruker IFS-25 spectrometer in films. Phosphine–
hydrogen mixture was prepared from red phosphorus, KOH and H2O
according to the published procedure.3
In fact, phosphine and allylbenzene under the action of the
superbasic catalytic system KOH–DMSO in the presence of
small amounts of water at 90–110 °C (2–2.5 h, atmospheric
pressure) afford Markovnikov products, namely (1-phenyl-
prop-2-yl)phosphine 1 and bis(1-phenylprop-2-yl)phosphine 2
(Scheme 1). Phosphine was generated in a separate reactor by
the addition of aqueous KOH to the suspension of red phos-
phorus in toluene.3
Preparation of (1-phenylprop-2-yl)phosphine 1. To a suspension of
KOH·0.5H2O (20.0 g, 0.31 mol), DMSO (50 ml) and water (3 ml), blown
with argon and saturated with phosphine, a solution of allylbenzene (6.0 g,
0.05 mol) in DMSO (10 ml) was added dropwise for 1.5 h at 90 °C under
stirring and continuous passing of phosphine at a rate of 15 ml min–1.
The flow of phosphine was maintained at 90 °C for additional 0.5 h, then
the mixture was blown with argon, cooled, diluted with water (100 ml)
and extracted with diethyl ether (2×50 ml). The extract was washed with
water (3×30 ml), dried over K2CO3, diethyl ether was evaporated, and
the residue was fractionized in vacuo to give primary phosphine 1 (4.1 g,
53%), secondary phosphine 2 (2.1 g, 30%) and (E)-1-phenylprop-1-ene
(1.0 g, 17%).
KOH/DMSO (H2O)
PH3
+
90–110 °C, 2–2.5 h
1
For 1: colourless oil, bp 60–63 °C (1 Torr). H NMR (CDCl3) d: 1.12
Me
PH
Me
3
3
(dd, 3H, Me, JHH 7.0 Hz, JPH 13.1 Hz), 2.21–2.23 (m, 1H, CH,
3JHH 10.4 Hz, 3JHH 8.0 Hz), 2.67 (dm, 2H, PH, 1JPH 194 Hz, 3JHH 10.5 Hz,
3JHH 5.6 Hz), 2.64 and 2.74 (ddd, 2H, CH2, 2JHH 13.6 Hz, 3JHH 10.4 Hz,
3JHH 8.0 Hz, 3JPH 8.1 Hz, 3JPH 7.2 Hz), 7.19–7.34 (m, 5H, Ph). 13C NMR
PH2
+
Me
a
b
2
1
1
(CDCl3) d: 22.54 (d, Me, JPC 9.2 Hz), 24.55 (d, CH, JPC 6.0 Hz),
2
45.87 (d, CH2, JPC 7.9 Hz), 126.38 (p-CPh), 128.46 (m-CPh), 129.15
2
(o-CPh), 140.81 (d, i-CPh,
3JPC 5.9 Hz). 31P NMR (CDCl3) d: –112.35
Scheme 1
(t, 1JPH 194 Hz). IR (KBr, n/cm–1): 3083, 3061, 3026, 2961, 2915, 2865,
2851, 2290, 1599, 1597, 1496, 1452, 1305, 1278, 1069, 1029, 963, 910,
736, 694. Found (%): C, 71.15; H, 8.50; P, 20.54. Calc. for C9H13P (%):
C, 71.04; H, 8.61; P, 20.35.
The conditions for the target preparation of either phosphine
1 or 2 have been elaborated. Primary phosphine 1 has been
synthesized in 53% yield by slow addition of allylbenzene to a
suspension of KOH–DMSO at 90 °C under continuous passing
a vigorous flow of phosphine through the suspension (the yield
of secondary phosphine 2 being 30%).† To attain the addition of
phosphine to two molecules of allylbenzene, the reaction was
carried out at higher temperature (90–110 °C), an extra equivalent
of allylbenzene being fed after the flow phosphine was ceased.
Under these conditions, phosphine 2 was obtained selectively in
80% yield, whereas neither primary 1 nor tertiary phosphines
were formed (31P NMR data).‡ The synthesized phosphines 1
For 2: colourless oil, bp 169–170 °C (1 Torr). IR (KBr, n/cm–1): 3080,
3060, 3024, 2968, 2917, 2865, 2850, 2294, 1601, 1598, 1491, 1455,
1304, 1276, 1040, 968, 914, 736, 695. Found (%): C, 79.83; H, 8.44;
P, 11.21. Calc. for C18H23P (%): C, 79.97; H, 8.58; P, 11.46. Major diastereo-
mer: 1H NMR (CDCl3) d: 1.03 (dd, 6H, Me, 3JHH 7.0 Hz, 3JPH 13.2 Hz),
2
2.07 (m, 2H, CH), 2.51 and 2.85 (ddd, 4H, CH2, JHH 10.0 Hz,
3JPH 9.9 Hz, 3JPH 8.0 Hz, 3JHH 10.0 Hz, 3JHH 5.9 Hz), 2.78–2.87 (m, 2H,
CH2), 3.03 (dm, 1H, PH), 7.10–7.26 (m, 10H, Ph). 13C NMR (CDCl3) d:
19.30 (d, Me, 2JPC 15.8 Hz), 27.29 (d, CH, 1JPC 10.6 Hz), 42.76 (d, CH2,
2JPC 13.9 Hz), 126.04 (p-CPh), 128.22 and 129.01 (o-CPh, m-CPh), 140.68
(d, i-CPh, 3JPC 8.1 Hz). 31P NMR (CDCl3) d: –22.76 (d, 1JPH 180.4 Hz).
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© 2010 Mendeleev Communications. All rights reserved.

Mendeleev Commun., 2010, 20, 275–276
In conclusion, the reaction of phosphine with allylbenzene in
Me
the superbasic system can serve (when applied to other alkenyl-
arenes) a simple, convenient and atom-economic route to new
primary and secondary phosphines. The phosphines obtained
are prospective ligands for metal complex catalysts,4 promising
precursors for valuable tertiary phosphines and corresponding
phosphine chalcogenides,5 as well as intermediates and coordinat-
ing solvents for the preparation of conductive nanomaterials.6
[1,3H]
KOH/DMSO
A
PH3
KOH/DMSO
A
1
2
A
KOH/DMSO
Scheme 2
This work was supported by the Russian Foundation for
Basic Research (grant no. 08-03-00251).
according to a nucleophilic addition mode to give primary
phosphine 1 which further interacts with 1-phenylprop-1-ene A
to produce secondary phosphine 2.
The intermediate (E)-1-phenylprop-1-ene was in fact isolated
from the reaction mixture,†,‡ which can be the evidence of the
above mechanism.
References
1 A. R. Stiles, F. F. Rust and W. E. Vaughan, J. Am. Chem. Soc., 1952, 74,
3282.
2 (a) B. A. Trofimov, S. N. Arbuzova and N. K. Gusarova, Usp. Khim.,
1999, 68, 240 (Russ. Chem. Rev., 1999, 68, 215); (b) B. A. Trofimov and
N. K. Gusarova, Mendeleev Commun., 2009, 19, 295.
3 N. K. Gusarova, S. F. Malysheva, V. A. Kuimov, N. A. Belogorlova,
V. L. Mikhailenko and B. A. Trofimov, Mendeleev Commun., 2008,
18, 260.
4 (a) N. Pillarsetty, K. Raghuraman, C. L. Barnes and K. V. Katti, J. Am.
Chem. Soc., 2005, 127, 331; (b) I. Kovacik, C. Scriban and D. S. Glueck,
Organometallics, 2006, 25, 536; (c) C. Scriban and D. S. Glueck, J. Am.
Chem. Soc., 2006, 128, 2788; (d) M. Kakeya, M. Tanabe, Y. Nakamura
and K. Osakada, J. Organomet. Chem., 2009, 694, 2270.
5 (a) S. F. Malysheva and S. N. Arbuzova, in Sovremennyi organicheskii
sintez (Modern Organic Synthesis), ed. D. L. Rakhmankulov, Khimiya,
Moscow, 2003, p. 160 (in Russian); (b) O. Delacroix and A. C. Gaumont,
Curr. Org. Chem., 2005, 9, 1851; (c) M. T. Honaker, J. M. Hovland and
R. N. Salvatore, Curr. Org. Synth., 2007, 4, 31.
6 (a) D. M. Stefanescu, D. S. Glueck, R. Siegel and R. E. Wasylishen,
Langmuir, 2004, 20, 10379; (b) D. M. Stefanescu, D. S. Glueck, R. Siegel
and R. E. Wasylishen, J. Clust. Sci., 2008, 19, 445.
Minor diastereomer: 1H NMR (CDCl3) d: 1.06 (dd, 6H, Me, 3JHH 7.0 Hz,
3JPH 13.2 Hz), 2.07, 2.47 and 2.81 (ddd, three-spin system ABM, 3H,
2
3
3
3
CH and CH2, JAB 10.0 Hz, JPH 8.0 Hz, JPH 9.8 Hz, JH
5.9 Hz,
AHM
A
3JH
10.0 Hz), 3.03 (dm, 1H, PH), 7.10–7.26B(m, 10H, Ph). 13C NMR
BHM
2
1
(CDCl3) d: 19.17 (d, Me, JPC 16.5 Hz), 27.28 (d, CH, JPC 10.6 Hz),
42.62 (d, CH2, 2JPC 13.2 Hz), 126.04 (p-CPh), 128.22 and 129.01 (o-CPh
,
m-CPh), 140.60 (d, i-CPh, 3JPC 7.3 Hz). 31P NMR (CDCl3) d: –28.26 and
1
–17.41 (d, JPH, 207.3 and 199.2 Hz). The presence of the three signals
in the 31P NMR spectrum can be due to the presence of asymmetric
centres in the molecule.
For (E)-1-phenylprop-1-ene: bp 35–40 °C (1 Torr). 1H NMR (CDCl3) d:
3
3
2.03 (d, 3H, Me, JHH 6.1 Hz), 6.37 (dd, 1H, =CHMe, JHH 15.4 Hz,
3JHH 6.1 Hz), 6.58 (d, 1H, =CHPh, 3JHH 15.4 Hz), 7.28–7.43 (m, 5H, Ph).
Found (%): C, 91.40; H, 8.41. Calc. for C9H10 (%): C, 91.47; H, 8.53.
‡
Preparation of bis(1-phenylprop-2-yl)phosphine 2. To a suspension
of KOH·0.5H2O (20.0 g, 0.31 mol), DMSO (50 ml) and water (3 ml),
blown with argon and saturated with phosphine, a solution of allyl-
benzene (7.8 g, 0.066 mol) in DMSO (10 ml) was added dropwise for
1.5 h at 90 °C under stirring and continuous passing of the phosphine at
a rate of 15 ml min–1. The phosphine feeding was stopped, the mixture
was blown with argon, and more solution of allylbenzene (3.9 g, 0.033 mol)
in DMSO (5 ml) was added. The reaction mixture was heated to 110 °C
and stirred for 1 h, then cooled, diluted with water (100 ml), and extracted
with diethyl ether (2×50 ml). The extract was washed with water (3×30 ml),
dried over K2CO3, diethyl ether was evaporated, and the residue was
fractionized in vacuo to give phosphine 2 (10.7 g, 80%) and (E)-1-phenyl-
prop-1-ene (1.5 g, 13%).
Received: 11th May 2010; Com. 10/3524
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