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Enantioselective addition of aryllithiums 2a-d (Ar = Ph (a), 2-MeC(6)H(4) (b), 2-MeOC(6)H(4) (c), 1-naphthyl (d)) to 6-(dimethylamino)fulvene (1) in the presence of (-)-sparteine in toluene at -78 degrees C generated chiral cyclopentadienyllithiums (4) substituted with an N,N-dimethylamino(aryl)methyl group, where the enantioselectivities are 51, 91, 90, and 83% for 4a, 4b, 4c, and 4d, respectively. Treatment of the chiral cyclopentadienides 4 with FeCl(2) or Fe(acac)(2) gave ferrocenes, which contain an N,N-dimethylamino(aryl)methyl side chain on both of the cyclopentadienyl rings. The enantiomeric purity of the chiral ferrocenes 7 thus obtained is 99% ee or higher for those containing a 2-MeC(6)H(4) (7b) or a 2-MeOC(6)H(4) (7c) group.

Abstract:A novel heterogeneous transition-metal catalyst comprising a polymer-supported terpyridine palladium(II) complex was prepared and found to promote the Suzuki-Miyaura, Mizoroki-Heck, Sonogashira, and Tsuji-Trost, reactions in water under aerobic conditions with a high to excellent yield. The catalyst was recovered by simple filtration and directly reused several times without loss of catalytic activity.

No abstract

A polymer-supported terpyridine Pd(II) complex was prepared and found to promote the SuzukiMiyaura coupling reaction in water. Thus, terpyridine ligand was prepared from p-hydroxybenzaldehyde, propane sultone, and 2-acetylpyridine according to the reported procedures. Immobilization of terpyridine ligand onto a polystyrene-poly(ethylene glycol) (PS-PEG) resin through ionic bonds to sulfonate group took place and the complexation of PS-PEG-terpyridine ligand with Pd(II) underwent to give PS-PEG-terpyridine-Pd(II) complex. This polymeric catalyst showed high catalytic activity and high reusability for the Suzuki-Miyaura coupling reaction.