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DOI: 10.1055/s-2004-837206
Preparation of Highly Functionalized Heterocyclic Zinc Organometallics via a Li(acac)-Catalysis of the I/Zn-Exchange Reaction
Publikationsverlauf
Publikationsdatum:
17. Dezember 2004 (online)
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Abstract
The reaction of i-Pr2Zn in the presence of catalytic amount of Li(acac) in NMP with various functionalized heterocyclic iodides provides new polyfunctional diheteroarylzincs, which undergo smooth Negishi cross-coupling reactions and CuCN·2LiCl-catalyzed allylation reactions under mild conditions. Remarkably, even an aldehyde function can be present in the diorganozinc reagents.
Key words
polyfunctional heterocycles - iodine-zinc exchange reaction - diorganozinc reagent - catalysis - cross-coupling
-
2a
Gilchrist TL. Heterocyclic Chemistry Longman; Harlow, UK: 1997. -
2b
Joule JA.Mills K.Smith GF. Heterocyclic Chemistry Stanley Thornes; Cheltenham, UK: 1998. -
3a
Cai X.Snieckus V. Org. Lett. 2004, 6: 2293 -
3b
Hartung CG.Fecher A.Chapell B.Snieckus V. Org. Lett. 2003, 5: 1899 -
3c
Chauder B.Larkin A.Snieckus V. Org. Lett. 2002, 4: 815 -
3d
Chauder B.Green L.Snieckus V. Pure Appl. Chem. 1999, 71: 1521 -
3e
Audoux J.Plé N.Turck A.Quéguiner G. Tetrahedron 2004, 60: 6353 -
3f
Rebstock A.-S.Mongin F.Trécourt F.Quéguiner G. Tetrahedron 2004, 60: 2181 -
3g
Dumouchel S.Mongin F.Trécourt F.Quéguiner G. Tetrahedron 2003, 59: 8629 -
3h
Quéguiner G. J. Heterocycl. Chem. 2000, 37: 615 - 4 For the preparation of some Grignard reagents with a keto group, see:
Kneisel FF.Knochel P. Synlett 2002, 1799 - 5
Kneisel FF.Dochnahl M.Knochel P. Angew. Chem. Int. Ed. 2004, 43: 1017 -
6a
Farina V.Krishnan B. J. Am. Chem. Soc. 1991, 113: 9585 -
6b
Farina V.Kapadia S.Krishnan B.Wang C.Liebeskind LS. J. Org. Chem. 1994, 59: 5905 -
7a
Negishi E.Valente LF.Kobayashi M. J. Am. Chem. Soc. 1980, 102: 3298 -
7b
Kobayashi M.Negishi E. J. Org. Chem. 1980, 45: 5223 -
7c
Negishi E. Acc. Chem. Res. 1982, 15: 340 -
7d
Tamaru Y.Ochiai H.Nakamura T.Yoshida Z. Tetrahedron Lett. 1986, 27: 955 - 8
Knochel P.Yeh MCP.Berk SC.Talbert J. J. Org. Chem. 1988, 53: 2390 - 9
Villieras J.Rambaud M. Synthesis 1982, 924 - 10
Sakamoto T.Kondo Y.Takazawa N.Yamanaka H. J. Chem. Soc., Perkin Trans. 1 1996, 1927 -
11a
Liu Y.Gribble GW. Tetrahedron Lett. 2000, 41: 8717 -
11b
Bergman J.Venemalm L. J. Org. Chem. 1992, 57: 2495 -
11c
Saulnier MG.Gribble GW. J. Org. Chem. 1982, 47: 757 - 12
Yang X.Althammer A.Knochel P. Org. Lett. 2004, 6: 1665 - 13
Collot V.Varlet D.Rault S. Tetrahedron Lett. 2000, 41: 4363 - 14
Gordon DW. Synlett 1998, 1065
References
Visiting professor from Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences.
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Typical Procedure for the Preparation of 4-Pyridin-3-yl-benzoic Acid Methyl Ester (
7a):
To a solution of 3-iodopyridine 5a (205 mg, 1.0 mmol) and Li(acac) (11 mg, 0.1 mmol) in anhydrous and degassed NMP (1 mL) was added i-Pr2Zn (5.0 M, 0.11 mL, 0.55 mmol) dropwise at r.t. under argon. The reaction mixture was stirred at r.t. for 12 h. The complete conversion of 3-iodopyridine to the zinc reagent was monitored by GC analysis. The zinc reagent 6a was treated with a solution of Pd(bda)2 (14 mg, 0.025 mmol), tri(2-furyl)phosphine (12 mg, 0.05 mmol) and methyl 4-iodobenzoate (393 mg, 1.5 mmol) in THF (2 mL). The resulting mixture was stirred at r.t. for 12 h, and was quenched with sat. aq NH4Cl. The aqueous layer was extracted with EtOAc (3 × 10 mL). The combined organic layers were washed with brine and dried (Na2SO4). After removal of the solvent, the residue was purified by column chromatography on silica gel (EtOAc-pentane = 1:2) to give the desired product 7a (176 mg, 83%) as a yellow solid; mp 102.0-102.8 °C. 1HMNR (300 MHz, CDCl3): δ = 3.93 (s, 3 H), 7.31-7.42 (m, 1 H), 7.63 (d, J = 8.4 Hz, 2 H), 7.90 (td, J = 7.9, 2.2, 1.8 Hz, 1 H), 8.12 (d, J = 8.8 Hz, 2 H), 8.62 (dd, J = 1.3, 4.9 Hz, 1 H), 8.86 (dd, J = 0.9, 2.2 Hz, 1 H) ppm. 13C NMR (75 MHz): δ = 52.2, 123.7, 127.1, 129.8, 130.4, 134.7, 135.7, 142.0, 148.0, 148.9, 166.7. IR (KBr): 2951, 1721, 1608, 1285, 1107, 767 cm-1. HRMS (EI): m/z calcd for C13H11NO2: 213.0790; found: 213.0795.