Pd-Catalysed Direct 5-Arylation of 1-Methylpyrazole with Aryl Bromides

被引:32
作者
Beladhria, Anissa [1 ,2 ]
Beydoun, Kassem [2 ]
Ben Ammar, Hamed [1 ]
Ben Salem, Ridha [3 ]
Doucet, Henri [2 ]
机构
[1] Univ Gabes, Lab Lab Chim Organ Appliquee, UR 12 13 99, Fac Sci Gabes, Gabes 6072, Tunisia
[2] Univ Rennes Catalyse & Organometall, UMR CNRS 6226, Inst Sci Chim Rennes, F-35042 Rennes, France
[3] Univ Sfax, Fac Sci Sfax, Lab Chim Organ Phys UR 12 13 99, Sfax 3038, Tunisia
来源
SYNTHESIS-STUTTGART | 2011年 / 16期
关键词
arylation; coupling; palladium; pyrazoles; regioselectivity; DIRECT C-2 ARYLATION; INCLUDING FREE (NH)-IMIDAZOLE; CROSS-COUPLING REACTIONS; H BOND-CLEAVAGE; HETEROAROMATIC-COMPOUNDS; REGIOSELECTIVE SYNTHESIS; LIGANDLESS CONDITIONS; PALLADIUM CATALYST; ROOM-TEMPERATURE; N-ALKYLATION;
D O I
10.1055/s-0030-1260076
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
1-Methylpyrazole was found to be a suitable partner for palladium-catalysed direct arylation through C-H activation/functionalisation using aryl bromides. The reaction conditions and the nature of the catalyst were found to have a determining influence on the selectivity. The use of an excess of pyrazole (4 equiv), and only 0.5-1 mol% palladium(II) acetate as the catalyst, potassium acetate as the base and DMAc as the solvent, promotes the 5-arylation in moderate to high selectivities and yields. A wide variety of aryl and heteroaryl bromide derivatives have been successfully employed. Their electronic and steric properties also have an influence on the regioselectivities and yields of the coupling products. Both electron-poor and electron-rich aryl bromides gave satisfactory results, although, very congested products were obtained with lower regioselectivities.
引用
收藏
页码:2553 / 2560
页数:8
相关论文
共 69 条
  • [1] Palladium-catalyzed direct arylations of 1,2,3-triazoles with aryl chlorides using conventional heating
    Ackermann, Lutz
    Vicente, Ruben
    Born, Robert
    [J]. ADVANCED SYNTHESIS & CATALYSIS, 2008, 350 (05) : 741 - 748
  • [2] Transition-Metal-Catalyzed Direct Arylation of (Hetero)Arenes by C-H Bond Cleavage
    Ackermann, Lutz
    Vicente, Ruben
    Kapdi, Anant R.
    [J]. ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 2009, 48 (52) : 9792 - 9826
  • [3] Aryl-aryl bond formation by transition-metal-catalyzed direct arylation
    Alberico, Dino
    Scott, Mark E.
    Lautens, Mark
    [J]. CHEMICAL REVIEWS, 2007, 107 (01) : 174 - 238
  • [4] Pd-mediated C-H arylation of EDOT and synthesis of push-pull systems incorporating EDOT
    Amaladass, P.
    Clement, J. Arul
    Mohanakrishnan, Arasambattu K.
    [J]. TETRAHEDRON, 2007, 63 (41) : 10363 - 10371
  • [5] Microwave-assisted intramolecular cyclization of electron-rich heterocycle derivatives by a palladium-catalyzed coupling reaction
    Beccalli, Egle M.
    Broggini, Glanluig
    Martinelli, Michela
    Sottocornolab, Silvia
    [J]. SYNTHESIS-STUTTGART, 2008, 1 (01): : 136 - 140
  • [6] Palladium- and copper-mediated direct C-2 arylation of azoles - Including free (NH)-imidazole, -benzimidazole and -indole - Under base-free and ligandless conditions
    Bellina, F
    Cauteruccio, S
    Rossi, R
    [J]. EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, 2006, 2006 (06) : 1379 - 1382
  • [7] Regiocontrolled synthesis of 1,2-diaryl-1H-imidazoles by palladium- and copper-mediated direct coupling of 1-aryl-1H-imidazoles with aryl halides under ligandless conditions
    Bellina, F
    Cauteruccio, S
    Mannina, L
    Rossi, R
    Viel, S
    [J]. EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, 2006, 2006 (03) : 693 - 703
  • [8] Highly selective synthesis of 4(5)-aryl-, 2,4(5)-diaryl-, and 4,5-diaryl-1H-imidazoles via Pd-catalyzed direct C-5 arylation of 1-benzyl-1H-imidazole
    Bellina, Fabio
    Cauteruccio, Silvia
    Di Fiore, Annarita
    Marchetti, Chiara
    Rossi, Renzo
    [J]. TETRAHEDRON, 2008, 64 (26) : 6060 - 6072
  • [9] Efficient and highly regioselective direct C-2 arylation of azoles, including free (NH)-imidazole, -benzimidazole and -indole, with aryl halides
    Bellina, Fabio
    Calandri, Chiara
    Cauteruccio, Silvia
    Rossi, Renzo
    [J]. TETRAHEDRON, 2007, 63 (09) : 1970 - 1980
  • [10] Recent advances in the synthesis of (hetero)aryl-substituted heteroarenes via transition metal-catalysed direct (hetero)arylation of heteroarene C-H bonds with aryl halides or pseudohalides, diaryliodonium salts, and potassium aryltrifluoroborates
    Bellina, Fabio
    Rossi, Renzo
    [J]. TETRAHEDRON, 2009, 65 (50) : 10269 - 10310