LETTER
Pd-Catalyzed Cross-Coupling of Haloarenes
1787
products (3016 and 31,17 respectively) could not be sur-
passed (Table 4, entries 1–4). Additionally, the total cou-
pling yield for the most selective case is rather poor
(Table 4, entry 4). The selectivity of the vinylation of 26
(Table 3, entry 3) is even worse as it displays a 1:2 ratio
of the mono- and bis-vinylated product (3218 and 33,19 re-
spectively). Moreover, it was not possible to separate the
obtained mixture of 26, 32 and 33 by means of flash chro-
matography nor HPLC. Nevertheless, the reaction of 26
with two equivalents of the vinylalane 1 under the proven
reaction conditions afforded 92% of the bis-vinylated
product 33 (Table 3, entry 4).
Schumann, H.; Blum, J. Tetrahedron Lett. 2000, 41, 7555.
(g) Blum, J.; Gelmann, D.; Baidossi, W.; Shakh, E.;
Rosenfeld, A.; Aizenshtat, Z.; Wassermann, B. C.; Frick,
M.; Heymer, B.; Schutte, S.; Wernik, S.; Schumann, H. J.
Org. Chem. 1997, 62, 8681. (h) Gelman, D.; Dechert, S.;
Schumann, H.; Blum, J. Inorg. Chim. Acta 2002, 334, 14.
(i) Blum, J.; Gelmann, D.; Aizenshtat, Z.; Wernik, S.;
Schumann, H. Tetrahedron Lett. 1998, 39, 5611.
(j) Schumann, H.; Kaufmann, J.; Wassermann, B. C.;
Girgdies, F.; Jaber, N.; Blum, J. Z. Anorg. Allg. Chem. 2002,
628, 971.
(7) Schumann, H.; Kaufmann, J.; Dechert, S.; Schmalz, H.-G.;
Velder, J. Tetrahedron Lett. 2001, 42, 5405.
(8) Schumann, H.; Kaufmann, J.; Dechert, S.; Schmalz, H.-G.
Tetrahedron Lett. 2002, 43, 3507.
(9) Typical experimental procedure: The vinylaluminium
reagent 1 (0.21 mg, 1.25 mmol), PdCl2(PPh3)2 (5 mol%, 0.06
mmol), and 2-bromonaphthalene(3) (0.26 g, 1.25 mmol)
were placed in a flame dried Schlenk-flask equipped with a
reflux condenser, evacuated and flushed with N2.
The tested desymmetrization of compound 25 employing
the chiral catalyst 35 furnished the monovinylated com-
plex 30 with poor selectivity (Table 4, entry 5) and small
enantioselectivity (16% ee of the (1R,2S)-enantiomer).
Finally, the reaction of the ester complex 27 afforded the
vinylated trifunctional compound 3420 in satisfying yield.
Deoxygenated anhyd THF (20 mL) was added via syringe.
The reaction mixture was stirred at 60 °C for 12 h under a N2
atmosphere, cooled to ambient temperature, diluted with n-
hexane (20 mL), filtered trough a short pad of silica gel,
washed with hexane and concentrated under reduced
pressure. The residue was purified by chromatography on
silica gel (20 g) with n-hexane–ethyl acetate = 10:1 to give
the product 4 as (0.19 g, 1.23 mmol, 98%) a colorless oil. 1H
NMR (CDCl3, 200 MHz): d = 8.27–8.32 (m, 1 H, Haryl),
7.93–8.04 (m, 2 H, Haryl), 7.80 (m, 1 H, Haryl), 7.57–7.72
(m, 4 H, Haryl, –CH=CH2), 5.97 (dd, 1 H, J = 1.58, 17.3 Hz,
–CH=CHHtrans), 5.65 (dd, 1 H, J = 1.58, 10.9 Hz,
In summary, we have demonstrated that the intramolecu-
larly stabilized vinyl- and allylaluminium compounds 1
and 2 are highly useful reagents for Pd-catalyzed cross-
alkenylation of bromo- and iodoarenes as well as chloro-
arene-Cr(CO)3 complexes. The developed procedure is
characterized by high yields of products and operational
simplicity.
Acknowledgment
–CH=CHcisH). 13C NMR (CDCl3, 50 MHz): d = 135.5, 134.3
(Cq), 133.6 (–CH=CH2), 131.1 (Cq), 128.5, 128.1, 126.0,
125.7, 125.6, 123.7, 123.6 (Caryl), 116.97 (–CH=CH2).
(10) See for instance: Wilhelm, R.; Widdowson, D. A. J. Chem.
Soc., Perkin Trans. 1 2000, 3808.
(11) For typical reactions and synthetic applications of styrene
Cr(CO)3 derivatives, see: (a) Semmelhack, M. F.; Seufert,
W.; Keller, L. J. Am. Chem. Soc. 1980, 102, 6584.
(b) Davies, S. G.; Furtado, O. M. L. R.; Hepworth, D.;
Loveridge, T. Synlett 1995, 69. (c) Gibson, S. E.; Gil, R.;
Prechtl, F.; White, A. J. P.; Williams, D. J. J. Chem. Soc.,
Perkin Trans. 1 1996, 1007. (d) Dehmel, F.; Schmalz, H.-G.
Org. Lett. 2001, 3, 3579. (e) Dehmel, F.; Lex, J.; Schmalz,
H.-G. Org. Lett. 2002, 4, 3915.
We thank the Fonds der Chemischen Industrie and the Deutsche
Forschungsgemeinschaft (Graduiertenkolleg ‘Synthetische, me-
chanistische und reaktionstechnische Aspekte von Metallkatalysa-
toren’). We also thank the A. v. Humboldt foundation for a
postdoctoral fellowship to B. G.
References
(1) (a) Diederich, F.; Stang, P. J. Metal-Catalyzed Cross-
Coupling Reactions; VCH: Weinheim, 1998. (b) Tsuji, J.
Palladium Reagents and Catalysis; Wiley and Sons:
Chichester, 1995.
(2) Stille, J. K. Angew. Chem., Int. Ed. Engl. 1986, 25, 508.
(3) For reviews, see: (a) Miyaura, N.; Suzuki, A. Chem. Rev.
1995, 95, 2457. (b) Suzuki, A. Metal-Catalyzed Cross-
Coupling Reaction; Diederich, F.; Stang, P. J., Eds.; VCH:
Weinheim, 1998, 48.
(4) Negishi, E. Organozinc Reactions; Knochel, P.; Jones, P.,
Eds.; Oxford University Press: Oxford, UK, 1999, Chap. 11.
(5) Kumada, M. Pure Appl. Chem. 1980, 52, 669.
(6) (a) Gotov, B.; Kaufmann, J.; Schumann, H.; Schmalz, H.-G.
Synlett 2002, 361. (b) Gotov, B.; Kaufmann, J.; Schumann,
H.; Schmalz, H.-G. Synlett 2002, 1. (c) Blum, J.; Katz, J. A.;
Jaber, N.; Michmann, M.; Schumann, H.; Schutte, S.;
Kaufmann, J.; Wassermann, B. C. J. Mol. Catal. A: Chem.
2001, 165, 97. (d) Baidossi, W.; Blum, J.; Frick, M.;
Gelmann, D.; Heymer, B.; Schumann, H.; Schutte, S.;
Shakh, E. Organic Synthesis via Organometallics, OSM 5;
Helmchen, G.; Dibo, J.; Flubach, D., Eds.; Vieweg & Sohn:
Braunschweig, 1997, 51. (e) Blum, J.; Berlin, O.; Milstein,
D.; Ben-David, Y.; Wassermann, B. C.; Schutte, S.;
Schumann, H. Synthesis 2000, 571. (f) Gelmann, D.;
(12) Typical experimental procedure: h6-(Vinylbenzene)-
tricarbonylchromium(0) (28). h6-(Chlorobenzene)tricar-
bonylchromium(0)(23) (124.3 mg, 0.5 mmol), vinylalane 1
(84.6 mg, 0.5 mmol) and PdCl2(PPh3)2 (17.6 mg, 0.025
mmol) were placed under Ar in a flame dried Schlenk flask
equipped with a reflux condenser. Deoxygenated anhydrous
THF (5.0 mL) was added via a syringe and the reaction
mixture was degassed three times. After stirring at 40 °C for
3 h the reaction mixture was cooled in an ice-bath, diluted
with n-hexane (5 mL), filtered through a short column of
silica gel (30 × 50 mm), eluted with n-hexane–MTBE = 8:1
(40 mL) and finally with n-hexane–MTBE = 4:1 (40 mL).
Upon concentration of the filtrate the obtained orange-
yellowish solid was recrystallized from MTBE–n-hexane to
afford 28 (114.3 mg, 0.476 mmol, 95.2%) as yellow-orange
crystals.
(13) h6-(Vinylbenzene)tricarbonylchromium(0)(28). 1HNMR
(C6D6, 250 MHz): d = 5.69 (dd, 1 H, J = 10.9, 17.5 Hz, –
CH=CH2), 5.11 (d, 1 H, J = 17.5 Hz, –CH=CHHtrans), 4.85
(d, 1 H, J = 10.9 Hz, –CH=CHcisH), 4.53 (yd, 2 H, Haryl),
4.43 (yt, 2 H, Haryl), 4.30 (m, 1 H, Haryl). 13C NMR (C6D6,
Synlett 2003, No. 12, 1783–1788 © Thieme Stuttgart · New York