Synthesis and coordination behavior of Cu(I) bis(phosphaethenyl)pyridine complexes

Cu(I) complexes bearing BPEP as a PNP-pincer type phosphaalkene ligand undergo effective bonding interactions with SbF(6)(-) and PF(6)(-) as non-coordinating anions to give [Cu(SbF(6))(BPEP)] and [Cu(2)(BPEP)(2)(μ-PF(6))](+), respectively [BPEP = 2,6-bis(1-phenyl-2-phosphaethenyl)pyridine]. NMR and theoretical studies indicate a reduced anionic charge of the μ-PF(6) ligand, which is induced by the strong π-accepting ability of BPEP.     

Catalytic applications of transition-metal complexes bearing diphosphinidenecyclobutenes (DPCB)

The preparation and characterization of sterically protected diphosphinidenecyclobutenes bearing two two-coordinate phosphorus atoms are described from the viewpoint of the development of a novel type of bidentate ligand for transition-metal complexes. They form complexes with group 6 metals such as chromium, molybdenum and tungsten, group 8 metals such as ruthenium, group 10 metals such as palladium and platinum, and group 11 metals such as copper and gold. Some of them can be used as catalysts for synthetic reactions such as cross-coupling of the Sonogashira type, Suzuki-Miyaura coupling, Ullmann coupling, Kosugi-Migita-Stille coupling, cyanation, polymerization of ethylene, dehydrogenative hydrosilylation of ketones, hydroamination of 1,3-butadienes, and direct alkylation or amination of allylic alcohols of Tsuji-Trost reactions.     

In vitro leishmanicidal constituents of Millettia pendula

The in vitro leishmanicidal constituents of Millettia pendula were examined. Two new compounds, 1 (millettilone A) and 2 (millettilone B), were isolated from the methanol extract of M. pendula, together with six known compounds: 3R-claussequinone (3), pendulone (4), secundiflorol I (5), 3,8-dihydroxy-9-methoxypterocarpan (6), 3,10-dihydroxy-7,9-dimethoxypterocarpan (7), and formononetin (8). Among these, pendulone showed the most potent leishmanicidal activity. Compound 2 was found to be a purple pigment in this heartwood. Their chemical structures were elucidated using spectral methods.