135138-76-0Relevant academic research and scientific papers
Cationic BINAP-Ru(II) Halide Complexes: Highly Efficient Catalysts for Stereoselective Asymmetric Hydrogenation of α- and β-Functionalized Ketones
Mashima, Kazushi,Kusano, Koh-hei,Sato, Naomasa,Matsumura, Yoh-ichi,Nozaki, Kyoko,et al.
, p. 3064 - 3076 (2007/10/02)
Cationic ruthenium-BINAP complexes 5, 7, and 10 of the formula Y, where X = Cl, Br, I; Y = Cl, Br, I, BF4, B(C6H5)4; arene = benzene, p-cymene, ethyl benzoate, and their enantiomers have been prepared by the reaction of arene-ruthenium halide complexes 4, 6, and 9 with (S)-BINAP or (R)-BINAP.Structures of the complexes were established by spectroscopy, conductivity, and a single-crystal X-ray analysis (5d: orthorhombic, P21212; a=20.141(2) Angstroem, b=18.504(1) Angstroem, c=12.241(1) Angstroem, V=4562.0(7) Angstroem3, Z=4, R=0.078 for unique 4177 reflections).BINAP derivatives with various substituents at the para and meta positions of four phenyl rings on phosphorus atoms and their cationic Ru(II) complexes have also been synthesized.These BINAP-Ru(II) complexes have been used as catalysts for the asymmetric hydrogenation of various unsaturated organic compounds such as α- and β-keto esters, allylic alcohols, and α,β-unsaturated carboxylic acids in excellent diastereo- and/or enantioselectivities.Catalytic activities and stereoselectivities depend highly on reaction conditions such as solvent, temperature, and additives.Variation of halogen ligands bound to ruthenium atom and substituents on four phenyl rings of BINAP also have exerted remarkable effects on the efficiency of the catalysis.Asymmetric hydrogenation of methyl (+/-)-2-(benzamidomethyl)-3-oxobutanoate catalyzed by the species derived from 9c and 3,5-(t-Bu)2-BINAP afforded the corresponding syn-(2S,3R)-17 in 98percent de and 99percent ee.
Synthesis of Partially Hydrogenated 2,2'-Bis(diphenylphosphenyl)-1,1'-binaphthyl (BINAP) Ligands and Their Application to Catalytic Asymmetric Hydrogenation
Zhang, Xiaoyong,Mashima, Kazushi,Koyano, Kinko,Sayo, Noboru,Kumobayashi, Hidenori,et al.
, p. 2309 - 2322 (2007/10/02)
Three pairs of new axially dissymmetric bisphosphane ligands, (R)-(-)- and (S)-(+)-2,2'-bis(dicyclohexylphosphanyl)-1,1'-binaphthyl , (R)-(+)- and (S)-(-)-2,2'-bis(diphenylphosphanyl)-5,5',6,6',7,7',8,8'-octahydro-1,1'-binaphthyl and (R)-(-)- and (S)-(+)-2,2'-bis(dicyclohexylphosphanyl)-5,5',6,6',7,7',8,8'-octahydro-1,1'-binaphthyl , have been synthesized.The absolute configurations of the isomers 2 were determined by single-crystal X-ray diffraction of the linear 1:1 polymeric complex of (S)-(+)-2,2'-bis(dicyclohexylphosphinoyl)-1,1'-binaphthyl and (2R,3R)-(-)-di-O-benzoyltartaric acid , and those of the isomers 3 and 4 were established on the basis of CD spectra of the phosphanes and their bisoxides.X-Ray crystallographic studies of two cationic RhI complexes, (cod)>ClO4 and (cod)>ClO4 , revealed that complex (S)-17 possesses a dissymmetric structure, while complex (S)-18 has a pseudo-C2-symmetry and shows a significantly large dihedral angle between the two phenyl rings .The potentiality of ligand 3 for asymmetric catalysis was demonstrated in RuII-catalysed stereoselective hydrogenations of methyl 2-(benzamidomethyl)-3-oxobutanoate (21, in up to 92percent d.e. and 99percent e.e.) and geraniol (22, in 98percent optical purity).
