Publications associées à New access to long-chain polyketides and spiroketals by umpolung of electron rich dienes with sulfur dioxide

Iodine oxoacids enhance nucleation of sulfuric acid particles in the atmosphere

Andrea Baccarini, Lubna Dada, André Welti, Houssni Lamkaddam, Imad El Haddad, Mihnea Surdu

The main nucleating vapor in the atmosphere is thought to be sulfuric acid (H2SO4), stabilized by ammonia (NH3). However, in marine and polar regions, NH3 is generally low, and H2SO4 is frequently found together with iodine oxoacids [HIOx, i.e., iodic acid ...

American Association for the Advancement of Science2023

Scalable Room-Temperature Synthesis of a Hydrogen-Sieving Zeolitic Membrane on a Polymeric Support

Kumar Varoon Agrawal, Mostapha Dakhchoune, Jian Hao, Xuekui Duan

Thescalable synthesis of high-temperature H-2-sieving membranesfor energy-efficient carbon capture can potentiallyenable the implementation of precombustion carbon capture at a rapidpace. ...

AMER CHEMICAL SOC2023

Synthesis and Applications of Ynimines and Enantioselective Total Synthesis of Artatrovirenol A

Rémi Hugo Lavernhe

The first chapter of this thesis describe the development of a general synthesis of ynimines, an under-exploited motif in organic chemistry. In the presence of an inexpensive copper catalyst and 2,2'-biquinoline, reaction of easily accessible O-acyloximes ...

EPFL2023

Genomic insights into the coupling of a Chlorella-like microeukaryote and sulfur bacteria in the chemocline of permanently stratified Lake Cadagno

Christel Sybille Hassler

Meromictic Lake Cadagno is a permanently stratified system with a persistent microbial bloom within the oxic-anoxic boundary called the chemocline. The association between oxygenic and anoxygenic photosynthesis within the chemocline has been known for at l ...

SPRINGERNATURE2023

Poisoning Effects of Cerium Oxide (CeO2) on the Performance of Proton Exchange Membrane Fuel Cells (PEMFCs)

Jan Van Herle, Hossein Pourrahmani

In this study, the poisoning effects of cerium oxide (CeO2) as the contaminant on the performance of proton exchange membrane fuel cells (PEMFCs) are evaluated. An experimental setup was developed to analyze the performance characteristic (I-V) curves in c ...

MDPI2022

Investigation of new particle formation mechanisms and aerosol processes at Marambio Station, Antarctic Peninsula

Lubna Dada

Understanding chemical processes leading to the formation of atmospheric aerosol particles is crucial to improve our capabilities in predicting the future climate. However, those mechanisms are still inadequately characterized, especially in polar regions. ...

Copernicus GmbH2022

Active anaerobic methane oxidation and sulfur disproportionation in the deep terrestrial subsurface

Rizlan Bernier-Latmani, Manon Frutschi, Emma Bell, Chen Qian

Microbial life is widespread in the terrestrial subsurface and present down to several kilometers depth, but the energy sources that fuel metabolism in deep oligotrophic and anoxic environments remain unclear. In the deep crystalline bedrock of the Fennosc ...

2022

Ring-Opening Reactions of Aminocyclopropanes and Aminocyclobutanes

Mingming Wang

Nitrogen-containing compounds are an important class of molecules in medicinal chemistry, chemical biology, biochemistry, material sciences or environmental sciences. Organic nitrogen occurs in many forms, ranging from small building blocks such as urea, a ...

EPFL2022

An evaluation of new particle formation events in Helsinki during a Baltic Sea cyanobacterial summer bloom

Marjan Marbouti, Lubna Dada

Several studies have investigated new particle formation (NPF) events from various sites ranging from pristine locations, including forest sites, to urban areas. However, there is still a dearth of studies investigating NPF processes and subsequent aerosol ...

Copernicus GmbH2022

Cyclative Release Strategy to Obtain Pure Cyclic Peptides Directly from the Solid Phase

Christian Heinis, Manuel Leonardo Merz, Sevan Mleh Habeshian, Ganesh Ashokrao Sable

The synthesis of large numbers of cyclic peptides-required, for example, in screens for drug development-is currently limited by the need of chromatographic purification of individual peptides. Herein, we have developed a strategy in which cyclic peptides ...

2022

Low‐Volatility Vapors and New Particle Formation Over the Southern Ocean During the Antarctic Circumnavigation Expedition

Robin Lewis Modini, Julia Schmale, Andrea Baccarini

During summer, the Southern Ocean is largely unaffected by anthropogenic emissions, which makes this region an ideal place to investigate marine natural aerosol sources and processes. A better understanding of natural aerosol is key to constrain the preind ...

2021

New Vinylation and Alkynylation Strategies with Hypervalent Iodine Reagents and Diazo Compounds

Guillaume Dominique Pisella

The development of a sequential copper-catalyzed oxy-alkynylation/intramolecular [4+2] cycloaddition of allenes and arenes was investigated at first. This one-pot protocol allowed the construction of complex polycylic architectures with high efficiency fro ...

EPFL2021

Diamine Synthesis via the Nitrogen-Directed Azidation of sigma- and pi-C-C Bonds

Jérôme Waser, Mingming Wang

Diamines are essential building blocks for the synthesis of agrochemicals, drugs, and organic materials, yet their synthesis remains challenging, as both nitrogens need to be differentiated and diverse substitution patterns (1,2, 1,3, or 1,4) are required. ...

2021

Methods for the generation of large combinatorial macrocycle libraries

Sevan Mleh Habeshian

Macrocycles are an attractive class of molecules due to their good binding properties and yet rather small size that allows, in many cases, crossing membranes to reach intracellular targets. In comparison to classical small molecule drugs, macrocycles are ...

EPFL2021

Enantioselective Total Synthesis of (+)-Alstilobanine C, (+)-Undulifoline, and (-)-Alpneumine H

Cyril Piemontesi, Nicolas David Gaeng, Qian Wang, Jieping Zhu, Guang Li

We report herein the enantioselective total synthesis of three monoterpene indole alkaloids, namely, (+)-alstilobanine C, (+)-undulifoline, and (-)-alpneumine H. The key features of our synthesis include: a) introduction of chirality via enantioselective d ...

Wiley-VCH Verlag GmbH2021

Natural Product Synthesis Enabled by Domino Processes Incorporating a 1,2-Rearrangement Step

Qian Wang, Jieping Zhu, Bastien Delayre

The art of natural product total synthesis is closely associated with two major determinants: the development/application of novel chemical reactions and the innovation in strategic use of classic organic reactions. While purposely seeking/applying a new s ...

2021

Iodic acid, sulfuric acid and methanesulfonic acid collected during the Arctic Ocean 2018 expedition

Julia Schmale, Andrea Baccarini

Measurements of iodic acid, sulfuric acid and methanesulfonic acid concentration in the gas phase obtained with a nitrate chemical ionization mass spectrometer (we used an APi-TOF mass spectrometer produced by Tofwerk AG coupled with a Chemical ionization ...

2020

Active sulfur cycling in the terrestrial deep subsurface

Rizlan Bernier-Latmani, Manon Frutschi, Emma Bell, Chen Qian

The deep terrestrial subsurface remains an environment where there is limited understanding of the extant microbial metabolisms. At Olkiluoto, Finland, a deep geological repository is under construction for the final storage of spent nuclear fuel. It is th ...

2020

Frequent new particle formation over the high Arctic pack ice by enhanced iodine emissions

Julia Schmale, Andrea Baccarini

In the central Arctic Ocean the formation of clouds and their properties are sensitive to the availability of cloud condensation nuclei (CCN). The vapors responsible for new particle formation (NPF), potentially leading to CCN, have remained unidentified s ...

Nature Research2020

Evaluation of materials for iodine and technetium immobilization through sorption and redox-driven processes

Daniel Teav Sun, Wendy Lee Queen

Radioactive iodine-129 (I-129) and technetium-99 (Tc-9(9)) pose a risk to groundwater due to their long half-lives, toxicity, and high environmental mobility. Based on literature reviewed in Moore et al. (2019) and Pearce et aL (2019), natural and engineer ...

ELSEVIER2020