The formation of a nickeladihydrofuran by oxidative cyclization of an alkyne and an aldehyde with nickel(0) has been demonstrated; the transformation of the nickeladihydrofuran into an enone by decomposition, a lactone by carbonylation and an allylic alcohol by treatment with ZnMe(2) suggests that nickeladihydrofuran is an important key intermediate in a variety of catalytic reactions.

AlMe3 can promote the oxidative cyclization of eta2-alkene and eta2-ketone on nickel(0) to give an intriguing nickel-aluminum dinuclear complex having a bridging methyl group, which might be an intermediate for the nickel-catalyzed cycloisomerization of o-allylacetophenone or o-allylbenzophenone.

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Phosphatidylinositol-3-phosphate (PI3P) is a lipid that is enriched specifically in early endosomes. Given that early endosomes containing PI3P act as a microdomain to recruit proteins that contain a PI3P-binding domain (FYVE domain), the equilibrium between the production and degradation of PI3P influences a variety of processes, including endocytosis and signal transduction via endosomes. In the study reported herein, we have developed a novel analytical method to quantify the amount of PI3P in endosomes by introducing a GST-2xFYVE protein probe into semi-intact cells. The GST-2xFYVE probe was targeted specifically to intracellular PI3P-containing endosomes, which retained their small punctate structure, and allowed the semi-quantitative measurement of intracellular PI3P. Using the method, we found that treatment of HeLa cells with H(2)O(2) decreased the amount of PI3P in endosomes in a p38 MAPK-dependent manner. In addition, H(2)O(2) treatment delayed transport through various endocytic pathways, especially post-early endosome transport; the retrograde transport of cholera toxin was especially dependent on the amount of PI3P in endosomes. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.

The use of Me 2 AlOTf as an additive allowed the oxidative cyclization of pivalaldehyde and diphenylacetylene with nickel(0) in the presence of PCy 3 to give an oxanickelacyclopentene, the structure of which was unambiguously determined by means of X-ray diffraction study. In the presence of TMSCHdCH 2 , treatment of the oxanickelacyclopentene with an equimolar amount of AlMe 3 quantitatively gave an oxaaluminacyclopentene with simultaneous generation of ethane and the Ni(0) species (PCy 3 )Ni-(TMSCHdCH 2 ) 2 . The oxaaluminacyclopentene was a suitable precursor for the preparation of allylic alcohol derivatives due to its reactive Al-C bond, and treatment with HCl or I 2 afforded (E )-4,4-dimethyl-1,2-diphenylpent-1-en-3-ol and (E)-PhCHdC(Ph)CH( t Bu)OH, and (Z)-1-iodo-4,4-dimethyl-1,2-diphenylpent-1-en-3-ol and (Z)-PhCIdC(Ph)CH( t Bu)OH, respectively, in excellent yield. This sequential reaction was successfully expanded to a Ni(0)-catalyzed three-component cyclocondensation reaction of an aldehyde, an alkyne, and AlMe 3 that gave the corresponding oxaaluminacyclopentenes in moderate to good yields. The scope of substrates and the mechanism of the reaction are also reported.