First Sonogashira coupling reactions with the chlorobenzeneCr(CO)2PPh3 complex

Article abstract of DOI:10.1016/S0022-328X(99)00215-6

Alkynylated benzeneCr(CO)₂PPh₃ complexes 4 are readily synthesized in moderate to good yields by Sonogashira couplings of the chlorobenzeneCr(CO)₂PPh₃ complex 2 with terminal alkynes 3.

Full text of DOI:10.1016/S0022-328X(99)00215-6

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 585 (1999) 174–178
First Sonogashira coupling reactions with the
chlorobenzeneCr(CO)2PPh3 complex
Markus Ansorge, Thomas J.J. Mu¨ller *
Institut fu¨r Organische Chemie der Ludwig-Maximilians-Uni6ersita¨t Mu¨nchen, Butenandtstr. 5-13 (Haus F), D-81377 Munich, Germany
Received 19 March 1999
Abstract
Alkynylated benzeneCr(CO)2PPh3 complexes 4 are readily synthesized in moderate to good yields by Sonogashira couplings of
the chlorobenzeneCr(CO)2PPh3 complex 2 with terminal alkynes 3. © 1999 Elsevier Science S.A. All rights reserved.
Keywords: Alkynes; Arene complexes; Chromium; Catalysis; Coupling reactions
tertiary amines [11]. However, the introduction of the
electronically donating phosphane ligands in the coor-
dination sphere of the chromium atom should render
the metal more electron rich and thus more or less
reluctant in cross-coupling reactions. Here we wish to
communicate our first findings on Sonogashira cou-
plings of the chlorobenzeneCr(CO)2PPh3 complex 2
with terminal alkynes 3.
1. Introduction
The advent of palladium-catalyzed cross-coupling re-
actions [1] has not only had a significant impact on the
synthesis of complex natural compounds [2] but has
also gained considerable importance in the development
of new organometallic structures with extended p-con-
jugation [3], especially for future opto-electronical and
electrical applications [4]. In terms of synthetic effi-
ciency, highly convergent strategies have emerged from
cross-coupling methodologies of bromo and iodoare-
nes, heteroarenes and numerous organometallics [1,5].
However, the less expensive chloroarenes have been
notorious for a long time and even the recently pre-
pared Herrmann–Beller catalyst [6] still requires higher
temperatures for efficient coupling rates. Interestingly,
the complexation of chloroarenes with the Cr(CO)3
fragment activates the arene chlorine bond considerably
towards the oxidative addition [7]. Thus, Cr(CO)3 com-
plexed chloroarenes react about 15 times faster than
iodoarenes in palladium-catalyzed cross-coupling reac-
tions [8,9] under mild reaction conditions, in particular
Sonogashira couplings [10] in refluxing THF and/or
2. Results and discussion
According to a standard procedure [12] we synthe-
sized the chlorobenzeneCr(CO)2PPh3 complex by irra-
diating
a
benzene solution of the chloroben-
zeneCr(CO)3 complex (1) in the presence of 1.1 equiva-
lents of triphenylphosphane for 5 h (Scheme 1). This
photochemical ligand exchange reaction can be moni-
tored by TLC as a spot-to-spot transformation indicat-
ing the formation of a less polar orange chlorobenzene
dicarbonyl phosphane complex 2.
Due to the increased acid sensitivity of 2 chromatog-
raphy on silica gel leads to rapid decomplexation.
Therefore, the purification was achieved by filtration
and recrystallization from diethyl ether. The complex 2
could be isolated as a pure orange crystalline material
in 50% yield.
* Corresponding author. Tel.: +49-89-21807714; fax: +49-89-
21807714.
E-mail address: tom@cup.uni-muenchen.de (T.J.J. Mu¨ller)
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00215-6

M. Ansorge, T.J.J. Mu¨ller / Journal of Organometallic Chemistry 585 (1999) 174–178
175
The chlorobenzeneCr(CO)2PPh3 complex 2 can be
4. Experimental
coupled with different terminal alkynes in THF/triethyl-
amine with Pd(PPh3)2Cl2 and CuI to furnish the com-
plexed alkynes 4 (Scheme 2). Most importantly, even
with the reduced acceptor capacity of the chromiumdi-
carbonyl-PPh3 fragment the chloroarene complex 2 still
can be successfully coupled with alkynes. The cross-cou-
pling products 4 are isolated in moderate to excellent
yields after purification by chromatography on silica gel.
Deprotection of the silylated alkyne 4d with TBAF in
THF furnishes the phenylacetylene complex 4e in excel-
lent yield as pure orange crystals.
The structure of the complexes 4a–4e is fully sup-
ported by NMR, IR and elemental analysis. In the
1H-NMR spectra the signals of the complexed arene
protons appear in the expected region between l=4.5
and 5.1. In the 13C-NMR spectra the signals of the
complexed arene are found between l=87.7 and 109.6.
The alkyne carbon resonances appear between l=79
and 86. They are slightly shifted to high field in compari-
son to those of the tricarbonylchromium complexes.
Most significantly, the CO resonances appear between
l=239.8 and 240.4, i.e. shifted to downfield by 6–8
ppm compared to the related tricarbonylchromium com-
plexes [11] due to the strong electron donating nature of
the phosphane ligand. Analogously, the two carbonyl
stretching vibrations in the IR spectra are shifted to
lower wavenumbers (1881–1903 and 1831–1842 cm−1),
indicating an increase in the electron density on the
metal and thus an enhanced backbonding to the car-
bonyl ligands.
All reactions involving tricarbonylchromium com-
plexes were carried out in flame-dried Schlenk flasks
under nitrogen by using septum and syringe techniques.
Solvents were dried and distilled according to standard
procedures [16]. Column chromatography: silica gel 60
(0.063–0.2 mm/70–230 mesh, Firma Merck Darm-
stadt). TLC: silica gel plates (60 F254 Merck, Darmstadt).
Melting points (uncorrected values): Reichert-Jung
Thermovar. The chlorobenzene complex 1 was synthe-
sized according to standard conditions [17]. The alkynes
and catalysts were purchased from Merck, Aldrich or
Fluka and used without further purification; 4-nitro-
phenylacetylene was synthesized according to literature
1
procedure [10]. H- and 13C-NMR spectra: Bruker WM
300, Bruker AC 300, Bruker ARX 300 or Varian VXR
400S; DMSO-d6. IR: Perkin–Elmer FT-IR spectrometer
1000 or Perkin–Elmer FT-IR Paragon 1000 PC. The
samples were pressed into KBr pellets and recorded on
NaCl plates. UV–vis: Beckman DK-2-a or Beckman UV
5240. UV–vis: Perkin–Elmer model Lambda 16. MS:
Finnigan MAT 311-A/100MS, Finnigan MAT 90 and
MAT 95 Q. Elemental analysis were carried out in the
Microanalytical Laboratories of the Institut fu¨r Organis-
che Chemie, Ludwig-Maximilians-Universita¨t Mu¨nchen.
4.1. (p6-C6H5Cl)Cr(CO)2(PPh3) (2)
The chlorobenzene complex 1 (1.00 g, 4.02 mmol) and
1.13 g (4.42 mmol) of triphenylphosphane were dissolved
in 150 ml benzene and the solution was irradiated for 8
h under a continuous flow of nitrogen in a reaction vessel
equipped with a water-cooled cold finger and a mercury
steam lamp (HPK 125W, Philips, quartz glass). The dark
red–brown reaction mixture was then filtered and the
solvent was evaporated in vacuo. Recrystallization of the
crude product from diethyl ether furnishes 1.96 g (50%)
of the chlorobenzene complex 2 as orange crystals, m.p.
158–160°C.
Although the substitution of a CO ligand by a phos-
phane decreases the propensity of the complexes towards
the oxidative addition of the palladium(0) species into
the carbon–chlorine bond, cross-couplings are still effi-
ciently possible. Nevertheless, for a complete conversion
of the coupling reaction of the chlorobenzene-
Cr(CO)2PPh3 complex 2 the reaction time has to be
extended to 24 h in a refluxing mixture of THF and
triethylamine. The coupling of the chlorobenzene-
Cr(CO)3 complex [11] 1 with terminal alkynes is com-
plete within 3 h.
1H-NMR (DMSO-d6, 300 MHz): l=4.58 (t, J=5.9
Hz, 1 H), 4.82–4.96 (m, 4 H), 7.32–7.43 (m, 15 H).
13C-NMR (DMSO-d6, 75 MHz): l=87.78 (CH), 88.27
(CH), 91.51 (CH), 109.65 (Cquat), 128.28 (CH, JP,C=8.6
Hz), 129.45 (CH, JP,C=1.3 Hz), 132.60 (CH, JP,C=10.6
3. Conclusions
Hz), 138.60 (Cquat, JP,C=33.8 Hz), 239.83 (Cquat, JP,C
=
Since these novel examples of organometallic alkynes
and propargyl alcohols are easily accessible via the
Sonogashira coupling of phosphane dicarbonyl-
chromium arene complexes, the application to other
cross-coupling reactions like the Suzuki [13], Stille [14]
and Heck [15] couplings lies at hand. Using this versatile
tool, the syntheses 2of novel organometallic NLO chro-
mophores and interesting organometallic build-
ing blocks for extended p-systems are currently under
way.
20.5 Hz). MS (70 eV, EI), m/z (%): 482 (M+, 8),
Scheme 1.

176
M. Ansorge, T.J.J. Mu¨ller / Journal of Organometallic Chemistry 585 (1999) 174–178
Scheme 2.
426 (M+ 2CO, 19), 314 ([Cr(PPh3)]+, 100), 262
([PPh3]+, 42), 52 (Cr+, 16). IR (KBr): w˜ =1903 cm−1
4.96 (m, 1 H), 5.10 (m, 2 H), 7.37 (m, 15 H), 7.66 (d,
J=8.4 Hz, 2 H), 8.23 (d, J=8.4 Hz, 2 H). 13C-NMR
(DMSO-d6, 75 MHz): l=81.77 (Cquat), 86.31 (Cquat),
89.21 (CH), 90.52 (CH), 93.03 (CH), 93.87 (Cquat),
124.08 (CH), 128.24 (CH, JP,C=8.6 Hz), 128.89 (Cquat),
129.42 (CH, JP,C=2.0 Hz), 132.56 (CH), 132.69 (CH,
,
1836, 1629, 1585, 1571, 1479, 1434, 1403, 1308, 1281,
1184, 1159, 1137, 1089, 1073, 1027, 1011, 998, 989, 844,
802, 746, 697, 684, 640, 607, 573, 522, 467, 428. UV–vis
(DMSO): umax (m)=326 nm (9800). C26H20ClCrO2P
(482.86): Calc.: C: 64.67, H: 4.17, Cl: 7.34, Found: C:
64.78, H: 4.16, Cl: 7.06.
J
P,C=10.6 Hz), 138.41 (Cquat, JP,C=34.5 Hz), 146.86
(Cquat), 240.28 (Cquat
,
J
P,C=21.2 Hz). 31P-NMR
(DMSO-d6, 121 MHz): l=86.71. MS (70 eV, EI), m/z
(%): 314 ([Cr(PPh3)]+, 4), 277 (100), 223 (M+
Cr(CO)2PPh3, 35), 52 (Cr+, 2). IR (KBr): w˜ =2214
cm−1, 1898, 1841, 1629, 1593, 1515, 1480, 1433, 1340,
1310, 1286, 1176, 1106, 1089, 1027, 998, 856, 829, 807,
747, 720, 696, 635, 604, 569, 522, 427. UV–vis
(DMSO): umax (m)=310 nm (25470), 472 (5010).
C34H24CrNO4P (593.53): Calc.: C: 68.80, H: 4.07, N:
2.36, Found: C: 68.56, H: 4.26, N: 2.49. m.p.: 133–
135°C.
4.2. Sonogashira coupling of the chlorobenzene complex
2
To a degassed solution of 1.00 g (2.07 mmol) of 2, 30
mg (0.04 mmol) of bis(triphenylphosphane) palladium
dichloride and 9 mg (0.04 mmol) of copper(I)iodide in
a mixture of 40 ml of THF and 20 ml of triethylamine
was added dropwise over a period of 1 h a solution of
the corresponding terminal alkyne (Table 1) in 10 ml of
THF. The reaction mixture was then heated to reflux
temperature for 24 h. After cooling to room tempera-
ture, 50 ml of diethyl ether was added, the mixture was
filtered and the filtrate was evaporated in vacuo. The
residue was chromatographed on silica gel with diethyl
ether and pentane as eluent to give the coupling prod-
ucts 4 as crystalline solids (Table 1).
Table 1
Experimental details of the coupling reactions of 2 with 3
Alkyne 3
Yield
334 mg (2.28 mmol) 4-nitrophenylacetylene
0.25 ml (2.50 mmol) 3-methyl-but-1-yn-3-ol
314 mg (2.50 mmol) 1-phenyl propyn-1-ol
0.50 g (41%) 4a
0.45 g (41%) 4b
0.58 g (48%) 4c
4.3. p-O2NC6H4CꢀC(p6-C6H5)Cr(CO)2(PPh3) (4a)
1H-NMR (DMSO-d6, 300 MHz): l=4.82 (m, 2 H),
0.59 ml (4.14 mmol) trimethylsilyl acetylene 1.00 g (89%) 4d

M. Ansorge, T.J.J. Mu¨ller / Journal of Organometallic Chemistry 585 (1999) 174–178
177
4.4. (H3C)2C(OH)CꢀC(p6-C6H5)Cr(CO)2(PPh3) (4b)
4.7. HCꢀC(p6-C6H5)Cr(CO)2(PPh3) (4e)
1H-NMR (DMSO-d6, 300 MHz): l=1.41 (s, 6 H),
4.59–4.81 (m, 5 H), 5.41 (s, 1 H), 7.39 (m, 15 H).
13C-NMR (DMSO-d6, 75 MHz): l=31.84 (CH3), 63.68
(Cquat), 78.71 (Cquat), 85.30 (Cquat), 89.71 (CH), 90.03
(CH), 91.90 (CH), 94.75 (Cquat), 128.20 (CH, JP,C=8.6
To a degassed solution of 1.00 g (1.83 mmol) of 4d in
50 ml of THF was added 0.57 g (1.83 mmol) of
tetrabutylammonium fluoride trihydrate. The mixture
was stirred for 1 h at room temperature, diethylether
was added and the solution was filtered through a short
plug of silica gel. The orange solution was evaporated in
vacuo to give 0.79 g (91%) of essentially pure 4e.
Recrystallization from pentane affords 0.60 g (69%) 4e
with a melting point of 135–140°C.
Hz), 129.30 (CH, JP,C=1.3 Hz), 132.67 (CH, JP,C
10.6 Hz), 138.88 (Cquat, JP,C=33.8 Hz), 240.45 (Cquat
P,C=22.8 Hz). MS (70 eV, EI), m/z (%): 530 (M+, 1),
=
,
J
474 (M+ 2 CO, 5), 314 ([Cr(PPh3)]+, 82), 262 ([PPh3]+,
100), 52 (Cr+, 18). IR (KBr): w˜ =3436 cm−1, 1895,
1842, 1633, 1480, 1434, 1270, 1163, 1089, 961, 903, 745,
696, 636, 605, 574, 522, 429. UV–vis (DMSO): umax
(m)=336 nm (8900). C31H27CrO3P (530.52): Calc.: C:
70.18, H: 5.13, Found: C: 69.19, H: 5.13. m.p.: 66–
71°C.
1H-NMR (DMSO-d6, 300 MHz): l=3.98 (s, 1 H),
4.68 (m, 2 H), 4.84 (m, 1 H), 4.98 (d, J=6.0 Hz, 2 H),
7.35 (m, 15 H). 13C-NMR (DMSO-d6, 75 MHz): l=
79.17 (Cquat), 82.06 (CH), 83.00 (Cquat), 89.59 (CH),
91.10 (CH), 92.03 (CH), 128.22 (CH, JP,C=8.6 Hz),
129.36 (CH), 132.63 (CH, JP,C=11.2 Hz), 138.71 (Cquat
,
J
P,C=34.5 Hz), 240.14 (Cquat, JP,C=20.5 Hz). MS (70
4.5. H5C6CH(OH)CꢀC(p6-C6H5)Cr(CO)2(PPh3) (4c)
eV, EI), m/z (%): 314 ([Cr(PPh3)]+, 7), 262 (PPh3+,
100), 52 (Cr+, 5). IR (KBr): w˜ =1896 cm−1, 1881,
1831, 1637, 1478, 1432, 1183, 1089, 997, 814, 744, 695,
638, 606, 572, 522, 513, 421. UV–vis (DMSO): umax
(m)=333 nm (8320). C28H21CrO2P (472.44): Calc.: C:
71.18, H: 4.48, Found: C: 71.33, H: 4.58.
1H-NMR (DMSO-d6, 300 MHz): l=4.67–4.99 (m, 5
H), 5.56 (d, J=5.8 Hz, 1 H), 6.16 (d, J=5.8 Hz, 1 H),
7.34–7.59 (m, 20 H). 13C-NMR (DMSO-d6, 75 MHz):
l=63.00 (CH), 82.87 (Cquat), 84.27 (Cquat), 89.29 (CH),
89.34 (CH), 89.76 (Cquat), 90.81 (CH), 92.06 (CH), 92.24
(CH), 126.75 (CH), 127.79 (CH), 128.14 (CH), 128.31
(CH, JP,C=8.6 Hz), 129.29 (CH, JP,C=1.3 Hz), 132.64
(CH, JP,C=10.6 Hz), 138.76 (Cquat, JP,C=33.8 Hz),
142.00 (Cquat), 240.37 (Cquat, JP,C=21.2 Hz). MS (70
eV, EI), m/z (%): 314 ([Cr(PPh3)]+, 15), 262 (PPh3,
100), 52 (Cr+, 6). IR (KBr): w˜ =3058 cm−1, 2924,
1968, 1894, 1842, 1637, 1479, 1452, 1433, 1382, 1309,
1285, 1185, 1158, 1089, 1026, 1000, 956, 918, 809, 745,
696, 636, 605, 572, 522, 428. UV–vis (DMSO): umax
(m)=336 nm (10000). C35H27CrO3P (578.56): Calc.: C:
72.65, H: 4.70, Found: C: 72.43, H: 4.91. m.p.: 55–
60°C.
Acknowledgements
The financial support of the Fonds der Chemischen
Industrie and the Deutsche Forschungsgemeinschaft is
gratefully acknowledged. We wish to express our appre-
ciation to Professor H. Mayr for his generous support.
References
[1] For excellent reviews, see (a) P.J. Stang, F. Diederich (Eds.),
Metal Catalyzed Cross Coupling Reactions, Wiley–VCH, Wein-
heim, 1998. (b) J. Tsuji, Palladium Reagents and Catalysts—In-
novations in Organic Synthesis, Wiley, New York, 1996.
[2] K.C. Nicolaou, E.J. Sorensen, Classics in Total Synthesis—
Targets, Strategies, Methods, Wiley–VCH, Weinheim, 1996.
[3] (a) U.H.F. Bunz, Pure Appl. Chem. 68 (1996) 309. (b) U.H.F.
Bunz, Synlett (1997) 1117. (c) M. Altmann, U.H.F. Bunz,
Angew. Chem. 107 (1995) 603; Angew. Chem. Int. Ed. Engl. 34
(1995) 569.
[4] For recent reviews on NLO materials see: (a) N.J. Long, Angew.
Chem. 107 (1995) 37; Angew. Chem. Int. Ed. Engl. 34 (1995) 6.
(b) S.R. Marder, J.W. Perry, Adv. Mater. 5 (1993) 804. (c) W.
Nie, Adv. Mater. 5 (1993) 520. (d) D.R. Kanis, M.A. Ratner,
T.J. Marks, Chem. Rev. 94 (1994) 195; For novel organometallic
NLO chromophores see, see: (e) M. Tamm, A. Grzegorzewski,
T. Steiner, T. Jentzsch, W. Werncke, Organometallics 15 (1996)
4984. (f) U. Behrens, H. Bussaard, U. Hagenau, J. Heck, E.
Hendrickx, J. Ko¨rnich, J.G.M. van der Linden, A. Persoons,
A.L. Spek, N. Veldman, B. Voss, H. Wong, Chem. J. Eur. 2
(1996) 98. (g) I.R. Whittall, M.G. Humphrey, S. Houbrechts, A.
Persoons, D.C.R. Hockless, Organometallics 15 (1996) 5738. (h)
P. Nguyen, G. Lesley, T.B. Marder, I. Ledoux, J. Zyss, Chem.
Mater. 9 (1997) 406.
4.6. (H3C)3SiCꢀC(p6-C6H5)Cr(CO)2(PPh3) (4d)
1H-NMR (DMSO-d6, 300 MHz): l=0.17 (s, 9 H),
4.72 (m, 2 H), 4.83–4.89 (m, 3 H), 7.39 (m, 15 H).
13C-NMR (DMSO-d6, 75 MHz): l=0.07 (CH3), 83.58
(Cquat), 89.38 (CH), 89.91 (CH), 92.39 (CH), 92.91
(Cquat), 103.82 (Cquat), 128.16 (CH, JP,C=8.6 Hz),
129.34 (CH, JP,C=1.3 Hz), 132.68 (CH, JP,C=10.6
Hz), 138.66 (Cquat, JP,C=33.8 Hz), 240.20 (Cquat, JP,C
=
20.5 Hz). MS (70 eV, EI), m/z (%): 544 (M+, 6), 488
(M+ 2 CO, 39), 314 ([Cr(PPh3)]+, 100), 262 (PPh3+,
77), 226 (M+ 2 CO–PPh3, 5), 52 (Cr+, 32). IR (KBr):
w˜ =2158 cm−1, 1972, 1900, 1842, 1667, 1586, 1572,
1512, 1480, 1448, 1308, 1249, 1218, 1185, 1158, 1119,
1089, 1069, 1027, 998, 844, 744, 721, 696, 633, 604, 570,
540, 521, 463, 427. UV–vis (DMSO): umax (m)=333 nm
(7600). C31H29CrO2PSi (544.62): Calc.: C: 68.36, H:
5.36, Found: C: 68.46, H: 5.36. m.p.: 58–61°C.

178
M. Ansorge, T.J.J. Mu¨ller / Journal of Organometallic Chemistry 585 (1999) 174–178
[10] S. Takahashi, Y. Kuroyama, K. Sonogashira, N. Hagihara,
[5] For alkynylated organometallics see: (a) M. Buchmeister, H.
Schottenberger, J. Organomet. Chem. 441 (1992) 457. (b) J.K.
Pudelski, M.R. Callstrom, Organometallics 11 (1992) 2757. (c)
C. Lo Sterzo, M.M. Miller, J.K. Stille, Organometallics 8 (1989)
2331. (d) C. Lo Sterzo, J.K. Stille, Organometallics 9 (1990) 687.
(e) J.E.C. Wiegelmann, U.H.F. Bunz, Organometallics 12 (1993)
3792. (f) U.H.F. Bunz, V. Enkelmann, Organometallics 13 (1994)
3823. (g) U.H.F. Bunz, V. Enkelmann, F. Beer, Organometallics
14 (1995) 2490.
Synthesis (1980) 627.
[11] (a) T.J.J. Mu¨ller, H.J. Lindner, Chem. Ber. 129 (1996) 607. (b)
T.J.J. Mu¨ller, M. Ansorge, H.J. Lindner, Chem. Ber. 129 (1996)
1433. (c) T.J.J. Mu¨ller, M. Ansorge, Chem. Ber. Recueil 130
(1997) 1135. (d) T.J.J. Mu¨ller, M. Ansorge, Tetrahedron 54
(1998) 1457.
[12] (a) W. Strohmeier, F.-J. Mu¨ller, Chem. Ber. 102 (1969) 3608. (b)
W. Strohmeier, H. Hellmann, Chem. Ber. 96 (1963) 2859. (c)
T.E. Bitterwolf, Polyhedron 7 (1988) 1377.
[13] (a) A. Suzuki, in: P.J. Stang, F. Diederich (Eds.) Metal Cata-
lyzed Cross Coupling Reactions, Wiley-VCH, Weinheim, 1998,
p. 49. (b) N. Miyaura, A. Suzuki, Chem. Rev. 95 (1995) 2457. (c)
S.P. Stanforth, Tetrahedron 54 (1998) 263.
[14] (a) V. Farina, V. Krishnamurthy, W.J. Scott, Org. React. 50
(1997) 1. (b) J.K. Stille, Angew. Chem. 98 (1986) 483; Angew.
Chem. Int. Ed. Engl. 25 (1986) 508.
8
[6] (a) W.A. Herrmann, C. Broßmer, K. Ofele, C.-P. Reisinger, T.
Priermeier, M. Beller, H. Fischer, Angew. Chem. 107 (1995)
1989; Angew. Chem. Int. Ed. Engl. 34 (1995) 1844. (b) M. Beller,
T.H. Riermeier, Tetrahedron Lett. 37 (1996) 6535. (c) M. Beller,
T.H. Riermeier, S. Haber, H.-J. Kleiner, W.A. Herrmann,
Chem. Ber. 129 (1996) 1259.
[7] For a review on palladium catalyzed reactions with halo arene
chromiumcarbonyl complexes, see: J.F. Carpentier, F. Petit, A.
Mortreux, V. Dufaud, J.-M. Basset, J. Thivolle-Cazet, J. Mol.
Catal. 81 (1993) 1.
[15] (a) S. Bra¨se, A. de Meijere, in: P.J. Stang, F. Diederich (Eds.),
Metal Catalyzed Cross Coupling Reactions, Wiley-VCH, Wein-
heim, 1998, p. 99. (b) A. de Meijere, F.E. Meyer, Angew. Chem.
106 (1994) 2473; Angew. Chem. Int. Ed. Engl. 33 (1994) 2379.
[16] Organikum, vol. 19, VEB Dt. Verl. der Wiss. Leipzig, 1993.
[17] C.A.L. Mahaffy, P.L. Pauson, Inorg. Synth. 28 (1990) 136.
[8] M.E. Wright, Organometallics 8 (1989) 407.
[9] (a) M. Uemura, H. Nishimura, T. Hayashi, Tetrahedron Lett. 34
(1993) 107. (b) M. Uemura, H. Nishimura, K. Kamikawa, Y.
Hayashi, Tetrahedron Lett. 35 (1994) 1909.
.
.