Most patients with metastatic prostate cancer will have metastasis to bone. Such patients are best monitored by serial radionuclide bone scans. One hundred sixty six men with bone metastasis from prostate cancer who received androgen deprivation therapy had their pretreatment bone scans reviewed using a semiquantitative grading system based upon the extent of disease (EOD) observed on the scan. The EOD on the scan correlated with survival. The 2-year survival rates for EOD I to IV were 94%, 74%, 68%, and 40%, respectively. The survival of patients in categories EOD I and IV significantly differed from the other categories. Men with metastatic prostate cancer entered into trials designed to evaluate the impact of treatment on survival should be stratified based upon the EOD on the bone scan. This analysis also indicates that patients in the EOD IV category have a particularly poor prognosis and may be candidates for alternative treatments.
C–N
cross-coupling is one of the most valuable and widespread
transformations in organic synthesis. Largely dominated by Pd- and
Cu-based catalytic systems, it has proven to be a staple transformation
for those in both academia and industry. The current study presents
the development and mechanistic understanding of an electrochemically
driven, Ni-catalyzed method for achieving this reaction of high strategic
importance. Through a series of electrochemical, computational, kinetic,
and empirical experiments, the key mechanistic features of this reaction
have been unraveled, leading to a second generation set of conditions
that is applicable to a broad range of aryl halides and amine nucleophiles
including complex examples on oligopeptides, medicinally relevant
heterocycles, natural products, and sugars. Full disclosure of the
current limitations and procedures for both batch and flow scale-ups
(100 g) are also described.
Reductive electrosynthesis has faced long-standing challenges in applications to complex organic substrates at scale. Here, we show how decades of research in lithium-ion battery materials, electrolytes, and additives can serve as an inspiration for achieving practically scalable reductive electrosynthetic conditions for the Birch reduction. Specifically, we demonstrate that using a sacrificial anode material (magnesium or aluminum), combined with a cheap, nontoxic, and water-soluble proton source (dimethylurea), and an overcharge protectant inspired by battery technology [tris(pyrrolidino)phosphoramide] can allow for multigram-scale synthesis of pharmaceutically relevant building blocks. We show how these conditions have a very high level of functional-group tolerance relative to classical electrochemical and chemical dissolving-metal reductions. Finally, we demonstrate that the same electrochemical conditions can be applied to other dissolving metal–type reductive transformations, including McMurry couplings, reductive ketone deoxygenations, and epoxide openings.
The mechanistic foundation behind the identity of a phosphine ligand that best promotes a desired reaction outcome is often non-intuitive, and thus has been addressed in numerous experimental and theoretical studies. In this work, multivariate correlations of reaction outcomes using 38 different phosphine ligands were combined with classic potentiometric analyses to study a Suzuki reaction, for which the site selectivity of oxidative addition is highly dependent on the nature of the phosphine. These studies shed light on the generality of hypotheses regarding the structural influence of different classes of phosphine ligands on the reaction mechanism(s), and deliver a methodology that should prove useful in future studies of phosphine ligands.
The development of new methods to facilitate direct electron transfer (DET) between enzymes and electrodes is of much interest because of the desire for stable biofuel cells that produce significant amounts of power. In this study, hydroxylated multiwalled carbon nanotubes (MWCNTs) were covalently modified with anthracene groups to help orient the active sites of laccase to allow for DET. The onset of the catalytic oxygen reduction current for these biocathodes occurred near the potential of the T1 active site of laccase, and optimized biocathodes produced background-subtracted current densities up to 140 μA/cm 2 . Potentiostatic and galvanostatic stability measurements of the biocathodes revealed losses of 25% and 30%, respectively, after 24 h of constant operation. Finally, the novel biocathodes were utilized in biofuel cells employing two different anodic enzymes. A compartmentalized cell using a mediated glucose oxidase anode produced an open circuit voltage of 0.819 ( 0.022 V, a maximum power density of 56.8 ((1.8) μW/cm 2 , and a maximum current density of 205.7 ((7.8) μA/cm 2 . A compartment-less cell using a DET fructose dehydrogenase anode produced an open circuit voltage of 0.707 ( 0.005 V, a maximum power density of 34.4 ((2.7) μW/cm 2 , and a maximum current density of 201.7 ((14.4) μA/cm 2 .
The deployment of nonaqueous redox flow batteries for grid-scale energy storage has been impeded by a lack of electrolytes that undergo redox events at as low (anolyte) or high (catholyte) potentials as possible while exhibiting the stability and cycling lifetimes necessary for a battery device. Herein, we report a new approach to electrolyte design that uses physical organic tools for the predictive targeting of electrolytes that possess this combination of properties. We apply this approach to the identification of a new pyridinium-based anolyte that undergoes 1e electrochemical charge-discharge cycling at low potential (-1.21 V vs Fc/Fc) to a 95% state-of-charge without detectable capacity loss after 200 cycles.
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