Recent Developments for the Deuterium and Tritium Labeling of Organic Molecules.

Organic compounds labeled with hydrogen isotopes play a crucial role in numerous areas, from materials science to medicinal chemistry. Indeed, while the replacement of hydrogen by deuterium gives rise to improved absorption, distribution, metabolism, and excretion (ADME) properties in drugs and enables the preparation of internal standards for analytical mass spectrometry, the use of tritium-labeled compounds is a key technique all along drug discovery and development in the pharmaceutical industry. For these reasons, the interest in new methodologies for the isotopic enrichment of organic molecules and the extent of their applications are equally rising.

Ruthenium-Catalyzed Deuteration of Aromatic Carbonyl Compounds with a Catalytic Transient Directing Group.

Invited for the cover of this issue are Helfried Neumann, Matthias Beller and co-workers at the Leibniz-Institut für Katalyse e. V., Rostock and Hangzhou Normal University.

Ruthenium-Catalyzed Deuteration of Aromatic Carbonyl Compounds with a Catalytic Transient Directing Group.

A novel ruthenium-catalyzed C-H activation methodology for hydrogen isotope exchange of aromatic carbonyl compounds is presented. In the presence of catalytic amounts of specific amine additives, a transient directing group is formed in situ, which directs selective deuteration. A high degree of deuteration is achieved for α-carbonyl and aromatic ortho-positions.

Manganese-catalyzed selective C-H activation and deuteration by means of a catalytic transient directing group strategy.

A novel manganese-catalyzed C-H activation methodology for selective hydrogen isotope exchange of benzaldehydes is presented. Using DO as a cheap and convenient source of deuterium, the reaction proceeds with excellent functional group tolerance. High ortho-selectivity is achieved in the presence of catalytic amounts of specific amines, which in situ form a transient directing group.

A Novel NAD-RNA Decapping Pathway Discovered by Synthetic Light-Up NAD-RNAs.

The complexity of the transcriptome is governed by the intricate interplay of transcription, RNA processing, translocation, and decay. In eukaryotes, the removal of the 5'-RNA cap is essential for the initiation of RNA degradation. In addition to the canonical 5'-N7-methyl guanosine cap in eukaryotes, the ubiquitous redox cofactor nicotinamide adenine dinucleotide (NAD) was identified as a new 5'-RNA cap structure in prokaryotic and eukaryotic organisms.

Peptide-β-lactam Inhibitors of Dengue and West Nile Virus NS2B-NS3 Protease Display Two Distinct Binding Modes.

The β-lactam ring represents a valuable moiety that can induce covalent binding of an inhibitor to its target. In this study, we explored di- and tripeptides with β-lactam electrophilic warheads as inhibitors of dengue and West Nile virus NS2B-NS3 protease. Tripeptides with a (3)-β-lactam moiety displayed the highest activity, with IC and EC values in the lower micromolar range in biochemical and cellular assays.

Deprotonation, insertion and isomerisation in the post-functionalisation of tris-pyridyl aluminates.

Post-functionalisation of the aluminate anion [EtAl(6-R-2-py)3]- (6-R-2-py = 6-R-2-pyridyl, R = Me or Br) can be accomplished via nucleophilic addition of the pyridyl groups to the electrophilic C[double bond, length as m-dash]O group of aldehydes (RCH[double bond, length as m-dash]O) or by deprotonation of carboxylic acids (RCO2H). NMR spectroscopic and crystallographic studies show how 6-Me-2-py groups can detect chirality and reveal a new aspect of isomerism.

Modifying the donor properties of tris(pyridyl)aluminates in lanthanide(ii) sandwich compounds.

The coordination ability of tris(pyridyl)aluminates can be modified by the steric and electronic character of substituents at the 6-positions of their pyridyl rings. Whereas [EtAl(6-Me-2-py)] (1) coordinates strongly to lanthanide(ii) ions [Eu(ii) and Yb(ii)], [EtAl(6-Br-2-py)] (2) forms much weaker complexes, and [EtAl(6-CF-2-py)] does not coordinate at all. The modification of the donor ability of these ligands is investigated by solid-state studies of the Ln(ii) sandwich compounds and by competitive coordination studies in solution.

Hospital Readmissions from Patients' Perspectives.

Objectives: Healthcare expenditures in the United States have increased exponentially and hospital care accounts for one-third of these costs. Approximately 18% of hospitalized Medicare beneficiaries are being readmitted to the hospital within 30 days. Engaging patients in the discharge process can help better identify patients' postdischarge needs and implement more effective readmission prevention strategies.