Angewandte
Chemie
reaction mixture was stirred at this temperature for 10 h. The
completion of the metalation was checked by GC analysis of reaction
aliquots quenched with a solution of I2 in anhydrous THF. The
mixture was then cooled to À208C, CuCN·2LiCl (1m solution in THF,
1.1 mL, 1.1 mmol) was added, and the reaction mixture stirred for
15 min. Benzoyl chloride (0.353 g, 2.5 mmol) was added dropwise,
and the reaction mixture was slowly warmed to 258C and stirred for
1 h. The reaction mixture was quenched with saturated aqueous
NH4Cl solution (5 mL) and extracted with diethyl ether (3 15 mL),
and the collected extracts were dried over anhydrous MgSO4. After
filtration, the solvent was removed by evaporation in vacuo.
Purification by flash chromatography on silica gel (n-pentane/diethyl
ether, 3:1) furnished compound 13a (0.336 g, 83%) as a colorless
solid.
Received: May 4, 2007
Published online: August 27, 2007
Keywords: copper · cross-coupling · homogeneous catalysis ·
.
lithium chloride · organozinc compounds
[1] a) V. Snieckus, Chem. Rev. 1990, 90, 879; b) J. Clayden, C. C.
Stimson, M. Keenan, Chem. Commun. 2006, 1393; c) M.
Schlosser, Angew. Chem. 2005, 117, 380; Angew. Chem. Int.
Ed. 2005, 44, 376; d) K. W. Henderson, W. J. Kerr, Chem. Eur. J.
2001, 7, 3431; e) A. Turck, N. PlØ, F. Mongin, G. QuØguiner,
Tetrahedron 2001, 57, 4489; f) F. Mongin, G. QuØguiner,
Tetrahedron 2001, 57, 4059; g) F. Levoux, P. Jeschke, M.
Schlosser, Chem. Rev. 2005, 105, 827; h) M. Kauch, D. Hoppe,
Synthesis 2006, 1578; i) W. Clegg, S. H. Dale, E. Hevia, G. W.
Honeyman, R. E. Mulvey, Angew. Chem. 2006, 118, 2430;
Angew. Chem. Int. Ed. 2006, 45, 2371; j) D. M. Hodgson, S. M.
Miles, Angew. Chem. 2006, 118, 949; Angew. Chem. Int. Ed. 2006,
45, 93; k) M. Yus, F. Foubelo, Handbook of Functionalized
Organometallics, Vol. 1 (Ed.: P. Knochel), Wiley-VCH, Wein-
heim, 2005, p. 7.
Scheme 2. Preparation of the polyfunctional aryl and heteroaryl diorga-
nozinc compounds 12a–c bearing an ester or lactone function.
[a] MgCl2 and LiCl are omitted for the sake of clarity. dba=dibenzylid-
eneacetone.
[2] a) P. E. Eaton, R. M. Martin, J. Org. Chem. 1988, 53, 2728;
b) P. E. Eaton, C.-H. Lee, Y. Xiong, J. Am. Chem. Soc. 1989, 111,
8016; c) P. E. Eaton, K. A. Lukin, J. Am. Chem. Soc. 1993, 115,
11370; d) M.-X. Zhang, P. E. Eaton, Angew. Chem. 2002, 114,
2272; Angew. Chem. Int. Ed. 2002, 41, 2169.
[3] a) O. Bayh, H. Awad, F. Mongin, C. Hoarau, L. Bischoff, F.
TrØcourt, G. QuØguiner, F. Marsais, F. Blanco, B. Abarca, R.
Ballesteros, J. Org. Chem. 2005, 70, 5190; b) E. Hevia, G. W.
Honeyman, A. R. Kennedy, R. E. Mulvey, D. C. Sherrington,
Angew. Chem. 2005, 117, 70; Angew. Chem. Int. Ed. 2005, 44, 68;
c) P. C. Andrikopolous, D. R. Armstrong, D. V. Graham, E.
Hevia, A. R. Kennedy, R. E. Mulvey, C. T. OꢀHara, C. Talmard,
Angew. Chem. 2005, 117, 3525; Angew. Chem. Int. Ed. 2005, 44,
3459; d) Y. Kondo, Y. Akihiro, T. Sakamoto, J. Chem. Soc.
Perkin Trans. 1 1996, 2331; e) P. E. Eaton, M.-X. Zhang, N.
Komiya, C.-G. Yang, I. Steele, R. Gilardi, Synlett 2003, 1275;
f) M. Shilai, Y. Kondo, T. Sakamoto, J. Chem. Soc. Perkin Trans.
1 2001, 442.
[4] a) K. Kitagawa, A. Inoue, H. Shinokubo, K. Oshima, Angew.
Chem. 2000, 112, 2594; Angew. Chem. Int. Ed. 2000, 39, 2481;
b) J. Farkas, S. J. Stoudt, E. M. Hannawalt, A. D. Pajeski, H. G.
Richey, Organometallics 2004, 23, 423; c) H. Awad, F. Mongin, F.
TrØcout, G. QuØguiner, F. Marsais, F. Blanco, B. Abarca, R.
Ballesteros, Tetrahedron Lett. 2004, 45, 6697.
Scheme 3. Preparation of diorganozinc compounds bearing an alde-
hyde or a nitro group. [a] MgCl2 and LiCl are omitted for the sake of
clarity.
Experimental Section
2: In an argon-flushed Schlenk flask, ZnCl2 (53.0 mmol, 7.22 g) was
dried in vacuo at 1408C for 4 h. After cooling to room temperature,
freshly titrated 1 (100 mmol, 1.00m, 100 mL) was added dropwise.
The resulting mixture was stirred for 15 h at 258C. The freshly
prepared solution of 2 was titrated prior to use at 08C with benzoic
acid using 4-(phenylazo)diphenylamine as indicator. A concentration
of 0.5m in THF was obtained.
[5] a) R. E. Mulvey, Organometallics 2006, 25, 1060; b) R. E.
Mulvey, Chem. Commun. 2001, 1049; c) M. Westerhausen,
Dalton Trans. 2006, 4755; d) R. E. Mulvey, F. Mongin, M.
Uchiyama, Y. Kondo, Angew. Chem. 2007, 119, 3876; Angew.
Chem. Int. Ed. 2007, 46, 3802.
13a: A dry and argon-flushed 10-mL Schlenk flask, equipped
with a magnetic stirring bar and a septum, was charged with a solution
of the 11a (0.301 g, 1.0 mmol) in anhydrous THF (1 mL). A solution
of 2 (0.50m in THF, 1.10 mL, 0.55 mmol) was added dropwise, and the
Angew. Chem. Int. Ed. 2007, 46, 7685 –7688
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim