Asymmetric synthesis of 4,4-disubstituted-2-imidazoli-dinones: potent NK1 antagonists

[structure: see text] A highly efficient and practical synthesis of 4,4-Disubstituted-2-Imidazolidinones utilizing a "self-reproduction of the center of chirality" strategy is described.     

Detecting functional magnetic resonance imaging activation in white matter: Interhemispheric transfer across the corpus callosum

Background  

It is generally believed that activation in functional magnetic resonance imaging (fMRI) is restricted to gray matter. Despite this, a number of studies have reported white matter activation, particularly when the corpus callosum is targeted using interhemispheric transfer tasks. These findings suggest that fMRI signals may not be neatly confined to gray matter tissue. In the current experiment, 4 T fMRI was employed to evaluate whether it is possible to detect white matter activation. We used an interhemispheric transfer task modelled after neurological studies of callosal disconnection. It was hypothesized that white matter activation could be detected using fMRI.     

Synthesis of carbobicyclic compounds via palladium-catalyzed cyclization/hydrosilylation: evidence for reversible silylpalladation

Cyclization/hydrosilylation of substituted 1-vinyl-1-(3-butenyl)cycloalkanes catalyzed by a 1:1 mixture of (phen)Pd(Me)Cl (1) and NaBAr(4) [phen = 1,10-phenanthroline; Ar = 3,5-C(6)H(3)(CF(3))(2)] formed silylated spirocycles in high yield with excellent regio and diastereoselectivity. Cyclization/hydrosilylation of substituted 3-(3-butenyl)cycloalkenes or 2,3-diallyl-5,6-dimethyl-1,4-hydroquinone diacetate (16) formed silylated fused bicyclic complexes in good yield. Reaction of substituted 1,6,11-nonatrienes with silane catalyzed by 1/NaBAr(4) led to cascade cyclization with hydrosilylation. This latter procedure was employed in the synthesis of silylated bicyclopentanes and a linear triquinane.