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ABSTRACT: The development of a highly active solid-phase catechol-copper network catalyst for direct aldol reaction is described. The catalyst was prepared from an alkyl-chain-linked bis(catechol) and a copper(II) complex. The direct aldol reaction between carbonyl compounds (aldehydes and ketones) and methyl isocyanoacetate was carried out using 0.1-1 mol% [Cu] catalyst to give the corresponding oxazolines at yields of up to 99% and a trans/cis ratio of >99:1. The catalyst was reused with no loss of catalytic activity. A plausible reaction pathway is also described.
Chemistry - An Asian Journal 09/2011; 6(9):2545-9. · 4.50 Impact Factor
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ABSTRACT: An in-water dehydrative alkylation with a novel heterobimetallic polymeric catalyst is described. Thus, a boron-iridium heterobimetallic polymeric catalyst was prepared by ionic convolution of a poly(catechol borate) and an iridium complex. The alkylation of ammonia and amines with alcohols, alkylating agents, was performed with 1 mol % Ir of the heterogeneous catalyst in water without the use of organic solvents under aerobic conditions to give the corresponding alkylated amines.
Organic Letters 06/2011; 13(15):3892-5. · 5.86 Impact Factor
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Angewandte Chemie International Edition 10/2008; 47(43):8310-4. · 13.45 Impact Factor
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ABSTRACT: A series of novel imidazolium salts bearing hydrophilic tetraethylene glycol (TEG) and/or hydrophobic long-chain alkyl (n-C12) functionalities, which are precursors for desired N-heterocyclic carbene (NHC) ligands, were synthesized and characterized. Rh(I)-NHC complexes were prepared in good yields by the silver carbene transfer method with NHC-Ag species derived from the imidazolium salts. The molecular structure of the Rh(I)-NHC complex having n-C12 chains has been determined by a single-crystal X-ray diffraction study and the complex is found to possess extended alkyl chains with anti conformations in the solid state. Hydrosilylation with the Rh(I) complexes and Suzuki-Miyaura coupling reactions with the Pd(II) complexes with these NHC ligands were carried out. In the latter case, the TEG moiety enhances catalytic activity considerably.
Dalton Transactions 02/2008; · 3.84 Impact Factor
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ABSTRACT: [reaction: see text] Bowl-shaped phosphine ligands were found to be highly effective in Suzuki-Miyaura coupling of unactivated aryl chlorides, in which the depth of the bowl affected the catalytic activity considerably.
Organic Letters 02/2007; 9(1):89-92. · 5.86 Impact Factor
