196207-83-7Relevant academic research and scientific papers
Chiral Pt(II)/Pd(II) pincer complexes that show C-H?Cl hydrogen bonding: Synthesis and applications to catalytic asymmetric aldol and silylcyanation reactions
Yoon, Myeong Sik,Ramesh, Rengan,Kim, Jeongryul,Ryu, Dowook,Ahn, Kyo Han
, p. 5939 - 5946 (2006)
A chiral C2-symmetric NCN ligand, (5R,7R)-1,3-bis(6,6-dimethyl-5,6,7,8-tetrahydro-5,7-methanoquinolin-2-yl)benzene has been synthesized. A direct cyclometalation of this ligand with K2MCl4 (M = Pt, Pd) in dry acetic acid offered the corresponding pincer complexes, [(5R,7R)-1,3-bis(6,6-dimethyl-5,6,7,8-tetrahydro-5,7-methanoquinolin-2-yl)phenyl]platinum(II) chloride 5a and its palladium(II) analogue 5b. The Pt(II) and Pd(II) complexes 5 were characterized by NMR spectroscopy, and X-ray crystal structure analysis was done for the Pt(II) complex. The NMR data for both the complexes and X-ray crystal structural data for the chloro-Pt(II) complex indicate the existence of intramolecular C-H?Cl hydrogen bonding both in solution and in solid states. Chloride abstraction from 5a by treatment with silver triflate resulted in the corresponding triflate complex 6a, which generates the corresponding cationic aqua complex 7a in the presence of water molecules. The Pt(II) complex 6a/7a was used as asymmetric catalyst in the aldol reaction between methyl isocyanoacetate and aldehydes and also in the silylcyanation of aldehydes.
Synthesis and application of cationic 2,6-bis(2-oxazolinylphenylpalladium(II) complexes
Stark, Mark A.,Richards, Christopher J.
, p. 5881 - 5884 (1997)
Treatment of 1,3-bis(2-oxazolinyl)benzenes with LDA/TMEDA followed by the addition of PdBr2(1,5-COD) gave 2,6-bis(2-oxazolinyl)phenylbromopalladium(II) complexes. Subsequent bromide abstraction with silver salts provided a series cationic 2,6-b
Palladium(II) pincer complexes of α-amino acids: Towards the synthesis of catalytically active artificial peptides
Guillena, Gabriela,Rodríguez, Gema,Van Koten, Gerard
, p. 3895 - 3898 (2002)
NCN palladium(II) complexes have been covalently attached to the N- and C-termini of L-valine and to the N-terminus of the dipeptide L-Phe-L-Val-OMe. Remarkably, the hydrolysis of the NCN-Pd(II) L-Val-OMe compound afforded the corresponding palladated, fr
Enantioselective Rh-catalyzed hydrogenation of N-formyl dehydroamino esters with monodentate phosphoramidite ligands
Panella, Lavinia,Aleixandre, Alicia Marco,Kruidhof, Gerlof J.,Robertus, Jort,Feringa, Ben L.,De Vries, Johannes G.,Minnaard, Adriaan J.
, p. 2026 - 2036 (2007/10/03)
Enantioselectivities up to >99% ee were achieved in the rhodium-catalyzed asymmetric hydrogenation of N-formyl dehydroamino esters using monodentate phosphoramidites as chiral ligands. The substrates were synthesized by condensation of methyl isocyanoacetate with a range of aldehydes and with cyclohexanone. A highly convenient multigram scale one step synthesis of methyl 2-(formamido)acrylate was developed. This compound was used in the synthesis of methyl 2-(formamido)cinnamate via a solvent free Heck reaction. Moreover, full conversion and >99% ee were obtained in 1 h in the hydrogenation of methyl 2-(formamido)acrylate with 0.2 mol% catalyst and 2 bar hydrogen pressure. The versatility of the formyl protection was established by its removal under mild conditions.
Hydroxyapatite-bound cationic ruthenium complexes as novel heterogeneous Lewis acid catalysts for Diels-Alder and aldol reactions
Mori, Kohsuke,Hara, Takayoshi,Mizugaki, Tomoo,Ebitani, Kohki,Kaneda, Kiyotomi
, p. 11460 - 11461 (2007/10/03)
Creation of a stable and well-defined active center on a solid surface is a promising protocol for designing more efficient hybrid-catalysts that bridge the gap between homogeneous and heterogeneous catalysis. Treatment of a hydroxyapatite-bound Ru complex (RuHAP) with an aqueous solution of AgX (X = SbF6-, TfO-) afforded a new type of cationic Ru phosphate complex, having potentially vacant coordination sites. These cationic RuHAPs exhibited Lewis acidity toward carbonyl and cyano groups, promoting Diels-Alder and Aldol reactions with high efficiencies. Moreover, no Ru leaching was detected in the above organic reactions, and then the catalysts were recyclable. Copyright
Oxazoline-carboxylic acid derivatives and method for the preparation thereof
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, (2008/06/13)
Optically active oxazoline-carboxylic acid derivatives of the formula: STR1 wherein R1 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkykl group which is substituted and has 1 to 20 carbon atoms, a cycloalkyl group, a cycloalkyl group which is substituted, a phenyl group, a phenyl group which is substituted, a vinyl group, a vinyl group which is substituted, an ethynyl group or an ethynyl group which is substituted; R2 represents a lower alkyl group having 1 to 4 carbon atoms or a benzyl group; R3 represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, a phenyl group or a benzyl group, and a method for preparing the above compounds and derivatives thereof involving a reaction between an aldehyde and an isocyano-carboxylate in the presence of a catalyst mixture.
