New Approach to Phosphinoalkynes Based on Pd- and Ni-Catalyzed Cross-Coupling of Terminal Alkynes with Chlorophosphanes

Article abstract of DOI:10.1021/ol035562c

(Equation presented) The first example of direct phosphination of terminal alkynes with chlorophosphanes catalyzed by Ni or Pd complexes is described. Both aromatic and aliphatic terminal acetylenes undergo the coupling reaction to give corresponding coup

Full text of DOI:10.1021/ol035562c

ORGANIC
LETTERS
2003
Vol. 5, No. 23
4309-4311
New Approach to Phosphinoalkynes
Based on Pd- and Ni-Catalyzed
Cross-Coupling of Terminal Alkynes
with Chlorophosphanes
Irina P. Beletskaya,* Vladimir V. Afanasiev, Marina A. Kazankova, and
Irina V. Efimova
Department of Chemistry, Moscow State UniVersity (MSU),
Leninskie Gory 1, building 3, 119992 Moscow, Russia
beletska@org.chem.msu.ru
Received August 20, 2003
ABSTRACT
The first example of direct phosphination of terminal alkynes with chlorophosphanes catalyzed by Ni or Pd complexes is described. Both
aromatic and aliphatic terminal acetylenes undergo the coupling reaction to give corresponding coupling product in high yield.
Alkynylphosphanes are an attractive and useful class of
compounds in organic synthesis.1 They can be identified as
common building blocks in constructing a broad variety of
alkenyl- and alkylphosphanes comprising functional groups2
and phosphorus heterocycles.3 Also, alkynylphosphanes are
important ligands, forming complexes with transition metals
through η1-P-coordination, as well as by simultaneous
participation of phosphorus UEP and acetylene π-orbitals
in polydentate binding.4
substantially restricts their application in obtaining of tertiary
alkynylphosphanes.
We report here a convenient and direct route to alkyn-
ylphosphanes by transition-metal-catalyzed cross-coupling
reaction that eliminates these problems.
The reaction of R2PH with aryl or vinyl halides catalyzed
by Pd or Ni complexes is known to be a convenient
procedure of obtaining tertiary phosphanes.6 The reaction
includes P-C bond formation as a result of nucleophilic
substitution at the C-atom (Scheme 1).
Synthesis of alkynylphosphanes is usually accomplished
by treating the respective P(III)-halide with acetylenides of
sodium,5a,b lithium,5a,b magnesium,5c,d or titanium.5e Obvi-
ously, the use of the above active organometallic compounds
Scheme 1
(1) (a) The Chemistry of Organophosphorus Compounds; Hartley, F. R.;
Ed.; Wiley: Chichester, U.K., 1990-1996; Vols. 1-4. (b) Quin, L. D. A
Guide to Organophosphorus Chemistry; Wiley: New York, 2000. (c)
Muller, E. Methoden der Organischen Chemie (Houben-Weyl); Georg
Thieme Verlag: Stuttgart, 1977; Band 5/Teil 2.
(2) (a) Taylor, N. J.; Carty, A. J. J. Chem. Soc., Dalton Trans. 1976,
799. (b) Carty, A. J.; Jacobson, S. E.; Taylor, N. J. J. Am. Chem. Soc.
1975, 97, 7254. (c) Carty, A. J.; Johnson D. K.; Jacobson, S. E. J. Am.
Chem. Soc. 1979, 101, 1, 5612. (d) Liu, X.; Mok, K. F.; Leung, P.-H.
Organometallics 2001, 20, 3918.
We proposed a novel catalytic method of synthesizing
phosphinoalkynes by Pd- or Ni-catalyzed reaction between
chlorophosphanes and alkynes in the presence of TEA, which
is inversed (Umpolung) to the above process (Scheme 1) and
can be considered as a nucleophilic substitution at the P-atom.
(Scheme 2)
(3) (a) Liu, X.; Ong, T. K. W.; Selvaratnam, S.; Vittal, J. J.; White A.
J. P.; Williams, D. J.; Leung, P.-H. J. Organomet. Chem. 2002, 643-644,
4. (b) Markl, G.; Matthes, D. Angew. Chem., Int. Ed. Engl. 1972, 11, 1019.
10.1021/ol035562c CCC: $25.00 © 2003 American Chemical Society
Published on Web 10/21/2003

acetylene in the presence of TEA even under heating at 80
°C for 24 h (Table 1, entry 1).8 The best catalysts are Ni-
(cod)2 and Ni(acac)2, with which cross-coupling proceeds
efficiently even at room temperature (Table 1, entries 6 and
10).
Scheme 2
The nature of the solvent does not noticeably affect the
rate of cross-coupling reaction. Thus, the cross-coupling
proceeds with equal success both in nonpolar toluene
(benzene) (Table 1, entries 4, 6, 8-11) and more polar CH2-
Cl2 or MeCN (Table 1, entries 5 and 7).
The discovered transformations appeared to be a het-
eroanalogue of the Sonogashira reaction7 in which the
phosphorus-halide bond is activated. The reaction proceeds
Under optimal conditions terminal alkynes easily react
with diaryl- and dialkylchlorophosphanes (Table 2, entries
Scheme 3
Table 2. Cross-Coupling of Chlorophosphanes with Alkynesa
smoothly by heating a toluene solution of alkyne (1),
chlorophosphane (2), Et3N, and 3 mol % catalyst at 80 °C
for 10-15 min or by allowing it to stand at room temperature
for 6-8 h. The respective phosphanes (3) are formed in
nearly quantitative yields.
Table 1. Effect of Catalyst, Solvent, and Temperature on
Cross-Coupling of Phenylacetylene with Chlorodiphenyl-
phosphanea
entry
catalyst
solvent temp (°C)/time conversionb (%)
1
2
3
4
5
6
7
8
PhMe
MeCN
(Ph3P)2PdCl2 PhMe
Ni(PPh3)2Br2 PhH
Ni(PPh3)2Br2 MeCN
80/24 h
0
50
95
97
99
95
99
99
99
98
98
Pd(PPh3)4
80/10 min
80/30 min
80/10 min
80/10 min
rt /10 h
80/10 min
80/10 min
80/10 min
rt /6 h
Ni(acac)2
Ni(acac)2
Ni(acac)2
Ni(cod)2
Ni(cod)2
PhMe
CH2Cl2
PhMe
PhMe
PhMe
9
10
11
Ni[P(OEt)3]4 PhH
120/15 min
a Reaction conditions: phenylacetylene, 1.25 mmol; Ph2PCl, 1 mmol;
catalyst, 3 mol %; Et3N, 3 mmol; solvent, 2 mL; sealed tube. b Determined
by 31P NMR.
The choice of catalytic system is represented in Table 1.
Various precursors of nickel catalyst were found to be
effective (Table 1, entries 4-11). Complexes of palladium
were found to be less active (Table 1, entries 2 and 3). In
the absence of catalyst Ph2PCl does not react with phenyl-
(4) See for example: (a) Moldes, J.; De la Encarnacion, E.; Ros, J.;
Alvarez-Larena, A.; Piniella, J. F. J. Organomet. Chem. 1998, 566, 165.
(b) Rosa, P.; Le Floch, P.; Richard, L.; Mathey, F. J. Am. Chem. Soc. 1997,
119, 9417. (c) Jeffery, J. C.; Pereira R. M. S.; Vargas, M. D.; Went, M. J.
J. Chem. Soc., Dalton Trans. 1995, 1805. (d) Johnson, D. K.; Rukachasirikul,
T.; Sun, Y.; Taylor, N. J.; Carty, A. J. Inorg. Chem. 1993, 32, 5544. (e)
Berenguer, J. R.; Bernechea, M.; Fornies, J.; Gomes, J.; Lalinde, E.
Organometallics 2002, 21, 2314. (f) Ara, J.; Falvello, L. R.; Fernandes, S.;
Fornies, J.; Lalinde, E.; Martin, A.; Moreno, T. Organometallics 1997, 16,
5923. (g) Lauattani, E.; Suades, J.; Matheim, R. J. Organomet. Chem. 1991,
421, 335.
a Reaction conditions: 80 °C, toluene, 3 mol % Ni(acac)2; (a) chloro-
phosphane 1 mmol, alkyne 1.25 mmol Et3N 3 mmol, (b) dichlorophosphane
1 mmol, alkyne 2.5 mmol, Et3N 6 mmol, (c) PCl31 mmol, alkyne 3.75
mmol, Et3N 9 mmol; (d) based on 31P NMR, value in parentheses is isolated
yield, (e) 120 °C, 2 weeks.
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Org. Lett., Vol. 5, No. 23, 2003

1-11), aryldichlorophosphanes (Table 2, entry 12), and PCl3
(Table 2, entries 13-17). In all cases mono-, bis-, or tris-
alkynylphosphanes are isolated in high yields, with the
exception of bulky chlorodi(tert-butyl)phosphane, which
forms the product of cross-coupling with phenylacetylene
in 25% yield only after heating at 120 °C for 2 weeks (Table
2, entry 18).
Scheme 5
It should be noted that selective substitution of one chlorine
atom upon treatment of dichlorophosphanes or PCl3 with 1
equiv of terminal alkyne proved problematic because a
mixture of alkynylphosphanes with predominance of di- and
trisubstituted derivatives is always formed. Terminal alkynes
which was transformed into the product of cross-coupling
(3) by reductive elimination.
Scheme 4
Oxidative addition of the P-Cl bond to zerovalent Ni and
Pd, unlike oxidative addition of the P-H bond, which is
considered to be the key step in hydrophosphination of
alkenes and alkynes,9 according to our knowledge is not
described in the literature.10 However there are several
examples of oxidative addition of the P-Cl bond to
zerovalent Pt11 and Fe12 complexes, as well as of insertion
of nontransition metal13 to the P-Cl bond. Only one case
of activation of a P(IV)-Cl bond by Pd(0)-complex, in
hexaphosphazene, has been reported.14
In summary, we have developed a novel straightforward
method of obtaining phosphinoalkynes via Pd- and Ni-
catalyzed cross-coupling of terminal alkynes with chloro-
phosphanes, which can be treated as heteroanalogues of the
Sonogashira reaction.
bearing alkyl and aryl substituents at the triple bond could
be introduced into the reaction with halogenophosphanes
under the stipulated conditions.
Unfortunately, the reaction of diphenylchlorophosphane
with with p-anisyl-, m-trifluoromethylphenylacetylenes, me-
thylpropargyl ether, and N,N-dimethylpropargylamine in the
presence of Ni-catalysts led to the complex mixture of
unidentified products.
The proposed mechanism of reaction is shown in Scheme
5. A first step of the catalytic cycle would be the oxidative
addition of halogenophosphane (1) to the catalyst to give a
phosphido complex (4). Subsequent transmetalation (ex-
change of halogen with acetylenide ion) led to complex (5),
Acknowledgment. We thank The Grant of Russian
Federation President Supporting Leading Scientific Schools,
1611.2003.03, for financial support. V.V.A. is grateful to
INTAS YSF 169 for financial support.
Supporting Information Available: Detailed experi-
mental procedures and compound characterization data. This
material is available free of charge via the Internet at
http://pubs.acs.org.
(5) (a) Davidsohn, W. E.; Henry, M. C. Chem. ReV. 1967, 73. (b) Ionin,
B. I.; Bogolubov, G. M.; Petrov, A. A. Russ. Chem. ReV. 1967, 36, 587.
(c) Charrier, C.; Chodkiewic, Z. W.; Cadiot, P. Bull. Chem. Soc. Fr. 1966,
1002. (d) Carty, A. J.; Hota, N. K.; Ng, T. W.; Patel, H. A.; O’Connor, T.
J. Can. J. Chem. 1971, 49, 2706. (e) Bharathi, P.; Periasamy, M.
Organometallics 2000, 19, 5511.
(6) (a) Beletskaya, I. P.; Kazankova, M. A. Russ. J. Org. Chem. 2002,
38, 1391. (b) Prim, D.; Campagne, J.-M.; Joseph, D.; Andrioletti, B.
Tetrahedron 2002, 58, 2041. (c) Allen, D. V.; Venkataraman, D. V. J. Org.
Chem. 2003, 68, 4590. (d) Gelman, D.; Jang, L.; Buchwald, S. L. Org.
Lett. 2003, 3, 2315.
(7) Hand Book of Organopalladium Chemistry for Organic Synthesis;
Negishi, E., Ed.; Wiley-VCH: New York, 2002.
(8) Noncatalytic reaction of PCl3 with phenylacetylene: Michailov, G.
J.; Trostyanskaya, I. G.; Kazankova, M. A.; Lutsenko, I. F. Zh. Obshch.
Chim. 1987, 57, 2636.
OL035562C
(10) For oxidative addition of E-Hal bond, see for example: (a) Kuyper,
J. Inorg. Chem. 1977, 16, 2171. (b) Kuyper, J. Inorg. Chem. 1978, 17, 77.
(c) Butler, G.; Eaborn, C.; Pidcock, A. J. Organomet. Chem. 1978, 144,
23. (d) Yamashita, H.; Hayashi, T.; Kobayashi, T.; Tanaka, M.; Goto, M.
J. Am. Chem. Soc. 1988, 110, 4417. (e) Chatani, N.; Amishiro, N.; Murai,
S. J. Am. Chem. Soc. 1991, 113, 7778. (f) Chatani, N.; Amishiro, N.; Morii,
T.; Yamashita, T.; Murai, S. J. Org. Chem. 1995, 60, 1834. (g) Yang, F.-
Y.; Cheng, Ch.-H. J. Am. Chem. Soc. 2001, 123, 761.
(9) For oxidative addition of phosphanes and phosphane oxides P-H
bond to Pt(0), Pd(0), or Ni(0) centers, see: (a) Jasaka, C. A.; Dorn, H.;
Lough, A. N.; Manners, L. Chem. Eur. J. 2003, 9, 271. (b) Han, L.-B.;
Tanaka, M. J. Am. Chem. Soc. 1996, 118, 1571. (c) Gianandrea, R.;
Mastrorilly, R.; Nolill, C. F.; Englert, U. J. Chem. Soc., Dalton Trans. 1997,
1355. (d) Wicht, D. K.; Glueck, D. S. In Catalytic Heterofunctionalization;
Togni, A., Grutzmacher, H., Eds.; Wiley-VCH: Weinheim, 2001; Chapter
5 and references therein.
(11) Cecconi, F.; Ghilardi, C. A.; Midollini, S.; Moneti, S.; Orlandini,
A.; Scapacci, G. Inorg. Chim. Acta 1991, 189, 105.
(12) Bitterer, F.; Brauer, D. J.; Doerrenbach, F.; Gol, F.; Knueppel, P.
C.; Stelzer, O.; Krueger, C.; Tsay, Y. H. Z. Naturforsch. B 1991, 46, 1131.
(13) Ager, D. J.; East, M. B.; Eisenstadt, A.; Laneman, S. A. Chem.
Commun. 1997, 2359.
(14) Rolland, H.; Potin, P.; Majoral, J.-P.; Bertrand, J. Tetrahedron Lett.
1992, 33, 8095.
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