In the presence of a Cu(ii) complex of axially chiral, N,N,O-tridentate phenanthroline ligand (S)-2, asymmetric oxygen atom transfer of oxindole derivatives (3) using Davis' oxaziridine (4) occurred to give the corresponding 3-aryl-3-hydroxy-2-oxindole derivatives (1) with excellent enantioselectivity (up to 96% ee). The X-ray crystallographic analysis of… (More)
The novel N,N,O-tridentate phenanthroline ligand (BinThro) bearing an axially chiral binaphthyl backbone prepared from BINOL was found to be an effective chiral catalyst for enantioselective addition of diethylzinc to aromatic aldehydes with high enantioselectivity (up to 95% ee).
The first catalytic synthesis of exocyclic 1,3-dienylphosphine oxides was achieved by the ruthenium-catalyzed selective hydrophosphinylative cyclization of 1,6-diynes. A plausible mechanism involving a ruthenacyclopentatriene intermediate is proposed on the basis of the DFT calculations of model ruthenium complexes.
Bis(oxazolinyl)phenyl ruthenium(II) complexes were found to catalyze asymmetric hydrogenation of ketones, in which chiral bulky alcohol additives showed significant enhancement of enantioselectivity even in protic solvents.
Safe program execution environment using sandboxing mechanism is one of important differences of Java<sup>1</sup> programming language and traditional languages. This safety characteristic can be preserved when a program is written in pure Java language, but it may be lost when machine-dependent native code is used in the program. We address this problem by… (More)
The first transfer-hydrogenative cyclization of 1,6-diynes that leads to exocyclic dienes was developed using a ruthenium catalyst and MeOH as a H(2) surrogate.
Bis(oxazolinyl)phenylrhodium(III) aqua complexes, (Phebox)RhX₂(H₂O) [X = Cl, Br], were found to be efficient Lewis acid catalysts for the enantioselective addition of allyl- and methallyltributyltin reagents to amino aldehydes. The reactions proceed smoothly in the presence of 5-10 mol % of (Phebox)RhX₂(H₂O) complex at ambient temperature to give the… (More)