A method for the efficient evaluation of substrate-based cholinesterase imaging probes for Alzheimer's disease.

Cholinesterase (ChE) enzymes have been identified as diagnostic markers for Alzheimer disease (AD). Substrate-based probes have been synthesised to detect ChEs but they have not detected changes in ChE distribution associated with AD pathology. Probes are typically screened using spectrophotometric methods with pure enzyme for specificity and kinetics.

Lewis Acid-Promoted Oxidative Addition at a [Ni (diphosphine) ] Complex: The Critical Role of a Secondary Coordination Sphere.

Oxidative addition represents a critical elementary step in myriad catalytic transformations. Here, the importance of thoughtful ligand design cannot be overstated. In this work, we report the intermolecular activation of iodobenzene (PhI) at a coordinatively saturated 18-electron [Ni (diphosphine) ] complex bearing a Lewis acidic secondary coordination sphere.

Preparation of a borane-appended Co(III) hydride: evidence for metal-ligand cooperativity in O-H bond activation.

Cobalt hydrides are known to mediate a number of important chemical transformations including proton (H), hydride (H), and hydrogen-atom (H˙) transfer. Central to the tunability of such frameworks is judicious ligand design, which offers the flexibility to alter fundamental properties relevant to reactivity. Herein, we report the preparation of one such cobalt(III) hydride: [Cp*Co(PB)(H)]BPh (Cp* = CMe, PB = 1,2-bis(di(3-dicyclohexylborane)propylphosphino)ethane) that is encircled by a boron-based Lewis-acidic secondary coordination sphere.

Platinum complexes of a boron-rich diphosphine ligand.

Herein, we describe the preparation, characterization, and reactivity of two PtII bis-hydrocarbyl complexes containing the 1,2-bis(di(3-dicyclohexylboraneyl)propylphosphino)ethane (P2BCy4) ligand. These scaffolds are readily accessed from four-fold hydroboration of 1,2-bis(diallylphosphino)ethane PtII precursors. The electrophilcity of such frameworks is showcased by facile coordination of the strong Lewis base, 4-N,N-dimethylaminopyridine (DMAP).

Octaboraneyl Complexes of Nickel: Monomers for Redox-Active Coordination Polymers.

Herein, we establish the preparation, characterization, and reactivity of a new diphosphine ligand, 1,2-bis(di(3-dicyclohexylboraneyl)propylphosphino)ethane (P B ), a scaffold that contains four pendant boranes. An entryway into the coordination chemistry of P B is established by using nickel, providing the octaboraneyl complex [Ni(P B ) ]-this species contains a boron-rich secondary coordination sphere that reacts readily with Lewis bases. In the case of 4,4'-bipyridine, an air-sensitive coordination polymer is obtained.