Pd-catalysed C-H functionalisation of free carboxylic acids.

Pd-catalysed C-H functionalisation of free carboxylic acids has drawn significant attention over the last few years due to the predominance of carboxylic acid moieties in pharmaceuticals and agrochemicals. But their coordinating ability was overlooked and masked by exogenous directing groups for a long time. Even other crucial roles of carboxylic acids as additives and steric inducers that directly influence the mode of a reaction have been widely neglected.

Phosphine-Catalyzed Aryne Oligomerization: Direct Access to α,ω-Bisfunctionalized Oligo(-arylenes).

A phosphine-catalyzed oligomerization of arynes using selenocyanates was developed. The use of JohnPhos as a bulky phosphine is the key to accessing α,ω-bisfunctionalized oligo(-arylenes) with RSe as the substituent at one terminus and CN as the substituent at the other. The formation of RPSeR' cations, serving as sterically encumbered electrophiles, hinders the immediate reaction that affords the 1,2-bisfunctionalization product and instead opens a competitive pathway leading to oligomerization.

Pd-Catalyzed Cyanoselenylation of Internal Alkynes: Access to Tetrasubstituted Selenoenol Ethers.

The intra- and intermolecular synthesis of selenium-substituted acyclic and heterocyclic acrylonitrile derivatives is presented. The 1,2-difunctionalization of several internal alkynes substituted not only by aliphatic and aromatic residues but also by heteroelements is realized by the Pd-catalyzed activation of aromatic and aliphatic selenocyanates. A high functional group tolerance allows straightforward access to a broad scope of tetrasubstituted olefins.

From 1,2-difunctionalisation to cyanide-transfer cascades - Pd-catalysed cyanosulfenylation of internal (oligo)alkynes.

Internal alkynes substituted by aliphatic or aromatic moieties or by heteroatoms were converted into sulphur-substituted acrylonitrile derivatives. Key is the use of Pd catalysis, which allows the addition of aromatic and aliphatic thiocyanates in an intra- and intermolecular manner. Substrates with several alkyne units underwent further carbopalladation steps after the initial thiopalladation step, thus generating in a cascade-like fashion an oligoene unit with sulphur at one terminus and the cyano group at the other.

Highly-sensitive open-cell LA-ICPMS approaches for the quantification of rare earth elements in natural carbonates at parts-per-billion levels.

This work presents a high-sensitivity approach to quantify ultra-trace concentrations of rare earth elements (REEs) in speleothem carbonates using open-cell laser ablation-sector field-inductively coupled plasma mass spectrometry (open-cell LA-SF-ICPMS). Specifically, open-cell LA in combination with a gas exchange device enabled sampling of large-scale carbonate specimens in an ambient environment. The use of a "jet" vacuum interface and the addition of small amounts of N gas allowed for a 20-40 fold sensitivity enhancement compared to the conventional interface configuration.

High-speed, high-resolution, multielemental LA-ICP-TOFMS imaging: part II. critical evaluation of quantitative three-dimensional imaging of major, minor, and trace elements in geological samples.

Here we describe the capabilities of laser-ablation coupled to inductively coupled plasma time-of-flight mass spectrometry (LA-ICP-TOFMS) for high-speed, high-resolution, quantitative three-dimensional (3D) multielemental imaging. The basic operating principles of this instrumental setup and a verification of 3D quantitative elemental imaging are provided. To demonstrate the potential of 3D LA-ICP-TOFMS imaging, high-resolution multielement images of a cesium-infiltrated Opalinus clay rock were recorded using LA with a laser-spot diameter of 5 μm coupled to ICP-TOFMS.

High-speed, high-resolution, multielemental laser ablation-inductively coupled plasma-time-of-flight mass spectrometry imaging: part I. Instrumentation and two-dimensional imaging of geological samples.

Low-dispersion laser ablation (LA) has been combined with inductively coupled plasma-time-of-flight mass spectrometry (ICP-TOFMS) to provide full-spectrum elemental imaging at high lateral resolution and fast image-acquisition speeds. The low-dispersion LA cell reported here is capable of delivering 99% of the total LA signal within 9 ms, and the prototype TOFMS instrument enables simultaneous and representative determination of all elemental ions from these fast-transient ablation events. This fast ablated-aerosol transport eliminates the effects of pulse-to-pulse mixing at laser-pulse repetition rates up to 100 Hz.

Element analysis of small and even smaller objects by ICPMS and LA-ICPMS.

Inductively coupled plasma mass spectrometry is increasingly used for non-traditional applications such as the analysis of solids at high spatial resolution when combined with laser ablation or the analysis of engineered nanoparticles. This report highlights recent projects and discusses the potentials and limitations these techniques offer. High-resolution laser ablation instrumentation allows element imaging at the μm-scale and can, therefore, be applied to, e.

[An interdisciplinary approach of the organ donation decision: the Lausanne's experience].

Since 2007, the Interdisciplinary Ethics Platform (Ethos) of the University of Lausanne is leading an interdisciplinary reflection on the organ donation decision. On this basis, the project "Organ transplantation between the rhetoric of the gift and a biomedical view of the body" studies the logics at stake in the organ donation decision-making process. Results highlight many tensions within practices and public discourses in the field of organ donation and transplantation and suggest lines of inquiry for future adjustments.