α-Arylation of cyclopentanone : palladium-catalyzed coupling of enamines and aryliodides & n-acyloxazines as novel bicyclic Weinreb amides

The introduction of an aryl group a to a carbonyl is a useful step in the preparation of a variety of biologically interesting compounds. The palladium-catalyzed a-arylation of ketones and esters, through their enolates, has received a great deal of attention lately. Despite these efforts, cyclopentanones remain one of the most difficult classes ofketones to arylate. Many of these methods suffer from the limitation of the relatively basic reaction conditions needed in order to prepare the enolate nucleopbiles in­situ. The direct palladium-catalyzed α-arylation of enamines as an alternative route to α­aryl ketones bas received very little attention and might be a way to circumvent the strong base problem. In an effort to overcome this problem a method for the direct palladium-cawyzed a-arylation of unactivated enamines of cyclopentanone through the use of high-throughput screening was developed. When applied to reactions with 1- pyrollidino-1-cylcopentane and various iodobenzene derivatives we have achieved yields of above 90% for the arylated cyclopentanone in all successful cases at a one mmol scale

Plasma Concentrations of Fentanyl Achieved With Transdermal Application in Chickens

Providing appropriate analgesia is an important concern in any species. Fentanyl, a μ-receptor specific opioid, use is common in mammalian species but has been incompletely evaluated for this purpose in avian species. Transdermal fentanyl patches were applied to domestic chickens (n = 10) of varying breeds for 72 hours. Repeated blood samples were collected from the birds to assess time-concentration of fentanyl and norfentanyl in plasma, as assayed by liquid chromatography-mass spectrometry, throughout patch application and for 48 hours after patch removal. Compartmental modeling was used to characterize the elimination profiles. Evaluation as a large bolus, followed by slower elimination rates over the remaining time, best fit the data as a one-compartment open model. Although maximum plasma fentanyl concentrations varied substantially by individual birds, chickens trended into 2 general groups of maximum plasma concentration, clearance, and volume of distribution, which was attributed to absorption variability. For all birds, harmonic mean of elimination half-life was 7.2 ± 3.7 hours and showed less individual variation than the other pharmacokinetic parameters. Because the application of transdermal fentanyl patches in the chickens achieved plasma fentanyl concentrations considered therapeutic in people, this approach could provide an additional analgesic option for avian patients

Dimensional crossover in the quantum transport behaviour of the natural topological insulator Aleksite

Three-dimensional topological insulators comprise topologically protected surface states displaying massless, Dirac-like linear dispersion with spin-momentum locking. Electrical conduction through such surface states has been documented to manifest itself in a two-dimensional character of the angle-dependent magnetotransport behavior. Here, we explore the size-dependent electronic properties of nanostructures made of the lead-containing mineral Aleksite, a naturally occurring topological insulator. Compared to its sister compound Kawazulite, a member of the wellstudied Tetradymite crystal class, the crystal structure of Aleksite is distinguished by its lack of any counterpart within the group of synthetic topological insulators. Low temperature Hall measurements on thin Aleksite nanosheets reveal a significant carrier mobility on the order of 1000 cm(2)/(Vs), and a high carrier density of n = 3.9 x 10(25) m(-3). Importantly, for Aleksite nanoribbons with a width below 150 nm, a 1D weak antilocalization effect along with 1D universal conductance fluctuations emerges, which transforms into 2D behavior for larger ribbon width