In: CHIMIA International Journal for Chemistry, 2016, vol. 70, no. 3, p. 182-185
The mechanism of photochemical reactions can be difficult to study because of the very short-lived intermediates involved. State-of-the art ultrafast spectroscopic tools can be used to probe these processes, but we will show in this account that old- fashioned techniques, such as the determination of quantum yields, the measurement of isotope effects or the use of triplet quenchers and...
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In: Bioconjugate Chemistry, 2015, vol. 26, no. 12, p. 2408–2418
Neuroscience studies require technologies able to deliver compounds with both scale and timing compatibility with morphological and physiological synaptic properties. In this light, two-photon flash photolysis has been extensively used to successfully apply glutamate or other neurotransmitters at the synaptic level. However, the set of commercially available caged compounds is restricted and...
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In: Chemistry – A European Journal, 2014, vol. 20, no. 26, p. 8062–8067
The quantum yield for the release of leaving groups from o-nitrobenzyl “caged” compounds varies greatly with the nature of these leaving groups, for reasons that have never been well understood. We found that the barriers for the primary hydrogen-atom transfer step and the efficient nonradiative processes on the excited singlet and triplet surfaces determine the quantum yields. The...
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In: Journal of Materials Chemistry B, 2014, vol. 2, no. 3, p. 247–252
This highlight describes recent trends in fundamental phospholipid research towards possible future drug delivery technology. In particular it focuses on synthetic phospholipids and their vesicular constructs and describes selected “smart” ways to release cargo from liposomes. Various chemical and physical release triggers are discussed such as temperature changes, application of ultrasound,...
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In: CHIMIA International Journal for Chemistry, 2013, vol. 67, no. 12, p. 896–898
The laboratory preparation of peptides, once a challenge, is now a standard operation that can be automatised. However, the need for particular protecting groups requiring relatively harsh conditions for their removal (strong acids or bases) and reactive coupling agents can be problematic in specific cases (e.g. in a cell or in a microfluidic device). In this account, we describe our efforts...
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In: The Journal of Organic Chemistry, 2013, p. -
In the present work, we report on a new intramolecular para-cycloaddition of arenes with allenes, yielding attractive rigid scaffolds bearing several reactive functionalities to build in further diversity. Bicyclo[2.2.2]octadiene-type products and benzoxepine acetals are formed in this reaction, in ratios and yields depending on the substitution pattern on the aromatic ring, the nature of the...
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In: European Journal of Organic Chemistry, 2012, no. 14, p. 2837–2854
Imidazolidin-4-ones are suitable in practical applications as hydrolytically cleavable precursors for the controlled release of fragrant aldehydes and ketones. The corresponding profragrances were prepared by treating aliphatic carbonyl compounds with commercially available amino acid amines in the presence of a base to yield mixtures of diastereomers. The two diastereomers isolated from the...
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In: Chemical Science, 2012, p. -
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In: Journal of the American Chemical Society, 2011, vol. 133, no. 14, p. 5380–5388
The possibility of wavelength-selective cleavage of seven photolabile caging groups from different families has been studied. Amine-, thiol-, and carboxylic-terminated organosilanes were caged with o-nitrobenzyl (NVOC, NPPOC), benzoin (BNZ), (coumarin-4-yl)methyl (DEACM), 7-nitroindoline (DNI, BNI), and p-hydroxyphenacyl (pHP) derivatives. Caged surfaces modified with the different chromophores...
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Thèse de doctorat : Université de Fribourg, 2011.
Organic chemistry may require the use of toxic substances and/or massive amount of energy. The environmental impact is amplified when such chemical reactions are scaled-up to the industrial level. A new concept, called green chemistry, has emerged and aims to minimize the negative effects of chemistry on the environment. Photochemistry fits in green chemistry, because the required photons are not...
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