Université de Fribourg

Photochemical methods in metathesis reactions

Harvey, Freya M. ; Bochet, Christian G.

In: Organic & Biomolecular Chemistry, 2020, vol. 18, no. 40, p. 8034–8057

Metathesis reactions are one of the most reliable and prevalent ways of creating a C– C bond in synthesis. Photochemical variants exist, and they have proven extremely useful for the construction of complex molecules, from natural products to Möbius rings. A variety of starting materials can undergo photometathesis reactions, including alkenes, alkynes, carbonyls, thiocarbonyls, and...

Université de Fribourg

A simple reaction for dna sensing and chemical delivery

Janett, Elia ; Diep, Kim-Long ; Fromm, Katharina M. ; Bochet, Christian G.

In: ACS Sensors, 2020, vol. 5, no. 8, p. 2338–2343

Reactions templated by nucleic acids are currently at the heart of applications in biosensing and drug release. The number of chemical reactions selectively occurring only in the presence of the template, in aqueous solutions, and at room temperature and able to release a chemical moiety is still very limited. Here, we report the use of the p-nitrophenyl carbonate (NPC) as a new reactive...

Université de Fribourg

On the sustainability of photochemical reactions

Bochet, Christian G.

In: CHIMIA International Journal for Chemistry, 2019, vol. 73, no. 9, p. 720–723

Photochemical reactions are often presented as intrinsically environmentally friendly ('green'). This may be indeed the case, but only in particular circumstances. This short essay comments on various aspects of the greenness of photochemical reactions, both in a historical (when only mercury-based hard UV light sources were available) and a current (with the recent introduction of LED...

Université de Fribourg

Photochemical amplifier based on self-immolative dendritic spacers

Kastrati, Agonist ; Bochet, Christian G.

In: The Journal of Organic Chemistry, 2019, vol. 84, no. 12, p. 7776–7785

A self-immolative dendritic structure was synthesized. It is based on phenol derivatives with three hydroxymethyl arms at both ortho and para positions of the core unit, potentially releasing up to 27 leaving groups in a third-generation dendrimer. The triggering event is the photolysis of a photosentive ortho-nitrobenzyl group. In doing so, we expected to transform a weak chemical or...

Consortium of Swiss Academic Libraries

Conflict-Free Chromatic Art Gallery Coverage

Bärtschi, Andreas ; Suri, Subhash

In: Algorithmica, 2014, vol. 68, no. 1, p. 265-283

Université de Fribourg

Application of photoclick chemistry for the synthesis of pyrazoles via 1,3‐dipolar cycloaddition between alkynes and nitrilimines generated in situ

Remy, Richard ; Bochet, Christian G.

In: European Journal of Organic Chemistry, 2018, vol. 2018, no. 3, p. 316–328

The photochemical extrusion of gaseous nitrogen from 2,5-disubstituted tetrazoles to generate reactive nitrilimines in situ represents an efficient and attractive way to form dipoles that can be used to provide useful chemicals via 1,3-dipolar cycloadditions. The concept of “photoclick chemistry” already inspired numerous researchers, who exploited photochemical processes involving...

Université de Fribourg

Photochemical C–H activation: generation of indole and carbazole libraries, and first total synthesis of clausenawalline D

Alimi, Isak ; Remy, Richard ; Bochet, Christian G.

In: European Journal of Organic Chemistry, 2017, vol. 2017, no. 22, p. 3197–3210

The photolysis of N-aryltriazoles and N-arylbenzotriazoles leads to indoles and carbazoles, respectively. Because libraries of triazoles can be accessed rapidly, for example by the copper-catalyzed [3+2] cycloaddition reaction between alkynes and azides, this reaction allows the preparation of indoles in a single operation, by the simultaneous photolysis of the precursor library. As an example of...

Consortium of Swiss Academic Libraries

Weak lensing tomography with orthogonal polynomials

Schäfer, Björn Malte ; Heisenberg, Lavinia

In: Monthly Notices of the Royal Astronomical Society, 2012, vol. 423, no. 4, p. 3445-3457

Consortium of Swiss Academic Libraries

Photochemical release of various functional groups

Bochet, Christian G.

In: Pure and Applied Chemistry, 2006, vol. 78, no. 2, p. 241-247

Université de Fribourg

Temporal mapping of photochemical reactions and molecular excited states with carbon specificity

Wang, K. ; Murahari, P. ; Yokoyama, K. ; Lord, J. S. ; Pratt, F. L. ; He, J. ; Schulz, Leander ; Willis, M. ; Anthony, J. E. ; Morley, N. A. ; Nuccio, Laura ; Misquitta, A. ; Dunstan, D. J. ; Shimomura, K. ; Watanabe, I. ; Zhang, S. ; Heathcote, P. ; Drew, Alan J.

In: Nature Materials, 2017, vol. 16, no. 4, p. 467–473

Photochemical reactions are essential to a large number of important industrial and biological processes. A method for monitoring photochemical reaction kinetics and the dynamics of molecular excitations with spatial resolution within the active molecule would allow a rigorous exploration of the pathway and mechanism of photophysical and photochemical processes. Here we demonstrate that...