Pergamon Tetrahedron Letters 41 (2000) 317–319 TETRAHEDRON LETTERS Montmorillonite–palladium–copper catalyzed cross-coupling of methyl acrylate with aryl amines Christophe Waterlot, a Daniel Couturier a and Benoît Rigo b,∗ a Laboratoire d’Ingéniérie Moléculaire, Université de Lille, 59655 Villeneuve d’Ascq, France b Laboratoire d’Ingéniérie Moléculaire, Ecole des Hautes Etudes Industrielles, 13 rue de Toul, 59046 Lille, France Received 27 September 1999; accepted 29 October 1999 Abstract Heck vinylation reactions of different anilines were performed with vinylacetate by using palladium chloride and copper nitrate intercalated montmorillonite K10 clay as catalyst. The substituted methylcinnamates were obtained in good yields without simultaneous side reaction to stilbenes. © 2000 Elsevier Science Ltd. All rights reserved. Keywords: arylation; heck reactions; aryl amines; montmorillonite; palladium; copper. Heck vinylation of substituted aromatics is one of the most frequently studied reactions in organic syn- thesis. The reaction is generally performed with aryl halides using homogeneous catalysts. 1–7 Recently, several publications have appeared on the development of heterogeneous catalysts 8–10 such as modified montmorillonite K10 clay 11,12 in order to perform Heck vinylation in a simple and inexpensive way. By comparison with palladium diacetate and triphenylphosphine, palladium intercalated montmorillonite K10 is less expensive for the synthesis of methyl substituted cinnamates from aryl halides (X=r, I). 13,14 From an industrial point of view, aryl halides have no considerable commercial interest because of further reactions leading to stilbenes 3,7,11,12 and the expensive cost of catalysts or halides used (X=Br, I). For these reasons, many studies on the amination of aryl halides 15–17 and on the vinylation of substituted anilines with inexpensive simple salts were realized. 18–21 In this framework, two different mechanisms have been suggested: the first one is a C–N bond cleavage of aryl amines when treated with palladium salts and acetic acid to give Ar–Pd–N species. 18 When the vinylation is performed in the presence of nitrites, 19,21 oxidative addition of aryldiazoniums to palladium occurred, yielding Ar–Pd species. 22 To the best of our knowledge, no direct synthesis of methyl cinnamates from anilines by using Pd–Cu exchanged montmorillonite K10 clay 23–25 (Pd–Cu–Mont.K10) as heterogeneous catalyst has been described. We thus investigate the use of this catalyst for the arylation of methyl acrylate with aryl amines (Scheme 1) and the influence of tert-butyl nitrite on this reaction. Our results are summarized in Table 1. By using the modified K10 clay as catalyst, good yields in methyl cinnamates were obtained from aromatic amines and no stilbenes by-products were formed. 27 This vinylation is selective and no side ∗ Corresponding author. E-mail: rigo@hei.fupl.asso.fr (B. Rigo) 0040-4039/00/$ - see front matter © 2000 Elsevier Science Ltd. All rights reserved. PII: S0040-4039(99)02082-1 tetl 16010