Synthesis of Lapatinib via direct regioselective arylation of furfural

A new synthesis of Lapatinib, an orally active drug for breast cancer, is described. The synthesis involves a palladium catalyzed regioselective arylation of furfural with 6-bromo-N-(3-chloro-4-((3-fluorobenzyl)oxy)phenyl)quinazolin-4-amine. This key step replaces an atom inefficient Suzuki cross coupling reaction used in a previously disclosed route and significantly shortens the synthesis.     

Matching radiation-dominated and matter-dominated Einstein–de Sitter universes and an application for primordial black holes in evolving cosmological backgrounds

By matching across a surface of constant time, it is demonstrated that the spacetime for a radiation-dominated Einstein–de Sitter universe can be directly matched to the spacetime for a matter-dominated Einstein–de Sitter universe. Thus, this can serve as a model of a universe filled with radiation that suddenly is converted to matter and antimatter, or a universe filled with matter and antimatter that suddenly annihilates to leave radiation. This matching is shown to hold for asymptotically Einstein–de Sitter cosmological black hole spacetimes, yielding simplistic models of primordial black holes that evolve between being in radiation-dominated universes and matter-dominated universes.     

GC-MS Determination of an Unknown Pesticide. II. An Experiment Investigating Quality of Analysis Using Random Sampling and Estimation of Variance

Newly devised components are described which significantly enhance both the scientific and pedagogical components of a previously published, qualitatively oriented experiment for students in an undergraduate instrumental analysis course. To provide a laboratory exercise containing as much real-world experience as possible, the earlier experiment was modified in such a way as to allow its use as a quantitative experiment illustrating such principles as sampling, experimental design, analysis of variance, and the use of internal standards.     

Reactivity of molecularly chemisorbed oxygen on a Au/TiO2 model catalyst

We present results of an investigation into the reactivity of molecularly chemisorbed oxygen with CO on a Au/TiO2 model catalyst at 77 K. We previously discovered that exposing the model catalyst sample to a radio-frequency-generated plasma jet of oxygen results in co-population of both atomically and molecularly chemisorbed oxygen species on the sample. We tested the reactivity of the molecularly chemisorbed oxygen by comparing the CO2 produced from a sample populated with both species to the CO2 produced from a sample that has been cleared of molecularly chemisorbed oxygen employing collision-induced desorption. Samples that are populated with both species consistently result in greater CO2 produced than samples with only atomic oxygen. We interpret this result to indicate that molecularly chemisorbed oxygen on the sample can directly participate in the CO oxidation reaction. The reactivity of molecularly chemisorbed oxygen has been investigated for five different gold coverages (0.5, 0.75, 1, 1.25, and 2 ML), and we observe that there is a greater fractional difference in the CO2 produced (difference between sample populated with both molecularly and atomically adsorbed oxygen and sample populated solely with atomically adsorbed oxygen) for the 1 ML Au coverage than for the other coverages for equivalent oxygen plasma-jet exposures. However, it is not possible to unambiguously conclude that this observation is directly related to a particle size effect on the chemistry since the absolute O(2,a) and O(a) content on the various surfaces is different for all the coverages studied because of the plasma-jet technique that we employed for populating the surfaces with oxygen. Unfortunately, this precludes a direct comparison of the reactivity of molecular oxygen in the carbon monoxide oxidation reaction as a function of gold coverage and hence particle size.     

Shot noise in graphene

We report measurements of current noise in single-layer and multilayer graphene devices. In four single-layer devices, including a p-n junction, the Fano factor remains constant to within +/-10% upon varying carrier type and density, and averages between 0.35 and 0.38. The Fano factor in a multilayer device is found to decrease from a maximal value of 0.33 at the charge-neutrality point to 0.25 at high carrier density. These results are compared to theories for shot noise in ballistic and disordered graphene.