Abstract
A systematic study of the cross-coupling capability of 4- and 5-substituted 2-phenylthiazoles under Stille conditions is presented. Two cross-coupling options were investigated: 1) combination of thiazolylstannanes with various aryl(hetaryl) halides and, 2) reaction of halothiazoles with PhSn(Bu)3 as coupling partner. The results obtained from the cross-coupling reactions on the 4- and 5-positions of the thiazole system were compared regarding the influence of the position of the halide (Br, I) and the Bu3 Sn group on both coupling partners. A broad selection of aromatic and heteroaromatic halides was coupled in order to establish a general reactivity platform for this heterocyclic system.
Key words
cross-coupling - heterocycles - thiazoles - palladium - Stille reaction
References and Notes
1a Rivkin A.
Cho YS.
Gabarda AE.
Yoshimura F.
Danishefsky SJ.
J. Nat. Prod.
2004,
67:
139
1b Nicolaou KC.
Roschangar F.
Vourloumis D.
Angew. Chem. Int. Ed.
1998,
37:
2014
1c Bach T.
Heuser S.
Angew. Chem. Int. Ed.
2001,
40:
3184
1d Plazzi PV.
Bordi F.
Silva C.
Morini G.
Caretta A.
Barocelli E.
Vitali T.
Eur. J. Med. Chem.
1995,
30:
881
1e Ganesh T.
Schilling JK.
Palakodety RK.
Ravindra R.
Shanker N.
Bane S.
Kingston DGI.
Tetrahedron
2003,
59:
9979
1f Shao J.
Panek JS.
Org. Lett.
2004,
6:
3083
2a Hattinger G, Stanetty P, and Eberle M. inventors; UK Patent Appl., GB 2369359.
; Chem . Abstr . 2002 , 137 , 216957
2b Stanetty P.
Roehrling J.
Schnürch M.
Mihovilovic MD.
Tetrahedron
2006,
62:
2380
2c Stanetty P.
Hattinger G.
Schnürch M.
Mihovilovic MD.
J. Org. Chem.
2005,
70:
5215
2d Mueller U, Eberle M, Pillonel C, Lutz W, and Stanetty P. inventors; PCT Int. Appl., WO 2003029249.
; Chem . Abstr . 2003 , 138 , 304297
3a Hantzsch A.
Ber. Dtsch. Chem. Ges.
1888,
21:
942
3b Schaumann E.
Georg Thieme Verlag;
Stuttgart Germany:
2002.
p.627
4 Carter JS.
Rogier DJ.
Graneto MJ.
Seibert K.
Koboldt CM.
Zhang Y.
Talley J.
J. Bioorg. Med. Chem. Lett.
1999,
9:
1167
5a Negishi E.
de Meijere A.
Wiley;
Hoboken N.J.:
2002.
5b Negishi E.
de Meijere A.
Wiley;
Hoboken N.J.:
2002.
5c De Meijere A.
Diederich F.
Metal-Catalyzed Cross-Coupling Reactions
2nd ed., Vol. 1:
Wiley-VCH;
Weinheim Germany:
2004.
5d De Meijere A.
Diederich F.
Metal-Catalyzed Cross-Coupling Reactions
2nd ed., Vol. 2:
Wiley-VCH;
Weinheim Germany:
2004.
5e Schnürch M.
Flasik R.
Khan A.
Spina M.
Mihovilovic MD.
Stanetty P.
Eur. J. Org. Chem.
2006,
15:
3283
6a Bach T.
Heuser S.
Tetrahedron Lett.
2000,
41:
1707
6b Hodgetts KJ.
Kershaw MT.
Org. Lett.
2002,
4:
1363
7a Stille JK.
Angew. Chem.
1986,
98:
504
7b Espinet P.
Echavarren AM.
Angew. Chem. Int. Ed.
2004,
43:
4704
8 Stanetty P.
Schnürch M.
Mihovilovic MD.
J. Org. Chem.
2006,
71:
3754
9 Erlenmeyer H.
Becker C.
Sorkin E.
Bloch H.
Suter E.
Helv. Chim. Acta
1947,
30:
2058
10 Begtrup M.
Hansen LBL.
Acta Chem. Scand.
1992,
46:
372
11a Schnürch M.
Spina M.
Khan AF.
Mihovilovic MD.
Stanetty P.
Chem. Soc. Rev.
2007,
36:
1046
11b Nora de Souza MV.
Curr. Org. Chem.
2007,
11:
637
11c Duan X.-F.
Zhang Z.-B.
Heterocycles
2005,
65:
2005
11d Fröhlich J.
Prog. Heterocycl. Chem.
1994,
6:
1
11e Bunnett JF.
Acc. Chem. Res.
1972,
5:
139
11f Stanetty P.
Schnürch M.
Mereiter K.
Mihovilovic MD.
J. Org. Chem.
2005,
70:
567
11g Stangeland EL.
Sammakia T.
J. Org. Chem.
2004,
69:
2381
11h Holzweber M.
Schnürch M.
Stanetty P.
Synlett
2007, in press
12 Crawforth CM.
Fairlamb IJS.
Kapdi AR.
Serrano JL.
Taylor RJK.
Sanchez G.
Adv. Synth. Catal.
2006,
348:
405
13 Littke AF.
Fu GC.
Angew. Chem. Int. Ed.
1999,
38:
2411
14
Typical Experimental Procedure : A solution of 3 (1 equiv, 200 mg, 0.44 mmol), iodobenzene (1.1 equiv, 100 mg, 0.49 mmol), Pd(PPh3 )4 (0.05 equiv, 25 mg, 0.02 mmol) and CsF (2.2 equiv, 148 mg, 0.98 mmol) in toluene (12 mL) was refluxed for 2 h under nitrogen. The reaction mixture was filtered over Celite® and evaporation of the solvent in vacuo gave a residue, which was purified by column chromatog-raphy (silica gel, PE-EtOAc, 10:1) to give 2,5-di-phenyl-thiazole (6a ; 82mg, 78%) as a colorless solid. All characteri-zation data of the obtained product were in agreement with those given in the literature.16
15a Goodson FE.
Wallow TI.
Novak BM.
J. Am. Chem. Soc.
1997,
119:
12441
15b Grushin VV.
Organometallics
2000,
19:
1888
16 Vernin G.
Aune JP.
Dou HJM.
Metzger J.
Bull. Soc. Chim. Fr.
1967,
4523
