We report the preparation of recyclable heterogeneous catalysts, copper-exchanged fluorapatite, and copper-exchanged tert-butoxyapatite by incorporating basic species F-/tBuO- in apatite in situ by coprecipitation and subsequent exchange with Cu(II). These basic copper catalysts catalyzed N-arylation of imidazoles and other heterocycles with chloroarenes and electron-poor fluoroarenes in good to excellent yields. Synthesis and characterization of some of the intermediates of the catalytic cycle gave some insight into the mechanism of the very important organic transformation. The necessity of basic sites for the activation of C-Cl and C-F bonds in the N-arylation of heterocycles with haloarenes is well-established.

The organometallic Ni(II) chemistry of the pyrrole-based pincer ligands, (P 2 R Pyr) − (P 2 R Pyr = 2,5-(R 2 PCH 2 ) 2 C 4 H 2 N, R = Ph or Cy) is reported. Reactions of Grignard reagents with [NiCl(P 2 R Pyr)] afford a variety of alkyl and aryl complexes (methyl, ethyl, benzyl, phenyl, and allyl) that all display square planar geometries about nickel. The hydride complex, [NiH(P 2 Cy Pyr)], can also prepared either through treatment of [NiCl(P 2 Cy Pyr)] with LiHBEt 3 , or by reaction of H(P 2 R Pyr) with [Ni(COD) 2 ] (COD = 1,4-cyclooctadiene). Reactions of the methyl and hydride complexes with CO and CO 2 , respectively, evince clean migratory insertion chemistry of the Ni-C and Ni-H bonds. Both the alkyl and chloride complexes are active catalysts for the Kumada coupling of aryl chlorides and aryl or alkyl Grignard reagents at room temperature. The solid-state structures of several of the complexes are reported.

N-Arylation of imidazoles and amines with arylboronic acids was accomplished with copper-exchanged fluorapatite (CuFAP) in methanol at room temperature. The products N-arylimidazoles and N-arylamines were isolated in good to excellent yields. A variety of arylboronic acids were converted to the corresponding N-arylimidazoles and N-arylamines, demonstrating the versatility of the reaction.

International audienceIron comes first, second, and third: By using the well-defined Cp-IMes iron cationic complex ([Fe], see scheme) as the catalyst, an efficient and versatile hydrosilylation reduction reaction of secondary and tertiary amides is performed in solvent-free conditions at 100 °C under visible light irradiation for 16 h to give the corresponding amines in good yields. When the reaction is performed with primary amides, the corresponding nitrile derivatives are obtained