Kazuki Wakabayashi

Catalyst self-adaptation in conjugate addition to nitroalkenes and nitroacrylates: instant chirality control in diphenylmethane-based phosphoramidite ligands.

The tropos diphenylmethane-based phosphoramidite ligand (A) provides high catalytic activity and enantioselectivity in the Cu catalysis of conjugate addition to nitroalkenes and nitroacrylate, by virtue of instant chirality control in A.

Achiral benzophenone ligand-rhodium complex with chiral diamine activator for high enantiocontrol in asymmetric transfer hydrogenation

The chirality of an achiral benzophenone-based rhodium complex can be controlled by chiral diamines to afford significantly high enantioselectivity in the catalytic asymmetric transfer hydrogenation of ketones (up to 99% ee, 99% yield).

Highly enantioselective spiro cyclization of 1,6-enynes catalyzed by cationic skewphos rhodium(i) complexElectronic supplementary information (ESI) available: typical experimental procedure and spectral data for 1?10. See http://www.rsc.org/suppdata/cc/b3/b310789b/

A cationic rhodium(I) complex having a skewphos ligand is shown to be a highly enantioselective catalyst for asymmetric carbocyclization of 1,6-enynes with tri-substituted olefins to control quaternary stereogenic centers of spiro-rings.

Change in temperature distribution by constriction of electric current through contact area

Abstract The change in temperature distribution due to constriction of an electric current through a contact area is analytically and numerically investigated. The potential distribution, current density distribution and heat density distribution inside the body are analytically obtained. The heat density has the singular point at the periphery of the contact area. It is revealed that the temperature has a finite value at the periphery, whereas the temperature change rate with respect to time has an infinite value because of the singularity. The results show the change in the temperature distribution. The times to melting and melting area are determined from the change in the temperature distribution. The total heat generated until melting occurs is also obtained.

Density distribution of point-contact current

The density distribution of point-contact current is theoretically investigated. Finite current is introduced to a semi-infinite body from the outside. The following assumptions are made: the contact area is circular, magnetic effects are ignored, the contact area is equipotential, the potential equals zero at an infinite distance from the contact area, and the electric permittivity and resistivity are constant. The density distribution of point-contact current for a non-steady state is obtained in an integral form and the derivation process is discussed. The results show that the current density distribution for the non-steady state agrees with that for the steady state. Further, the results suggest that the analytical solution of the density distribution of point-contact current for the steady state is applicable to thermal analysis as well.

HELICAL CHIRALITY CONTROL OF TROPOS SANDWICH-SHAPED L2M3 COMPLEXES WITH C3-SYMMETRIC TRIS(DIPHENYLPHOSPHINOPHENYL)BENZENE LIGAND

The L 2 M 3 complexes with tropos C 3 -symmetric ligands interconvert rapidly between the chiral propeller (P)- and (M)-helicity of the sandwich-shaped L 2 M 3 complexes at room temperature and are chirally controlled to adopt a single helical structure upon complexation with a chiral diamine. The L 2 M 3 complexes chirally controlled can be employed for asymmetric transfer hydrogenation.