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

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...

Université de Fribourg

Towards a photochemical synthesis of peptides

Bochet, Christian G.

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...

Université de Fribourg

Singlet-Oxygen-Induced Rearrangement of Furan Derivatives

Charbonnet, Nicolas ; Riguet, Emmanuel ; Bochet, Christian G.

In: Synlett, 2012, vol. 15, p. 2231-2233

photochemistry; heterocycles; singlet oxygen; rearrangement; pyrroles; furans

Université de Fribourg

Hard work and light experience: early steps in photochemistry

Bochet, Christian G.

In: Chimia, 2009, vol. 63, no. 12, p. 872-873

The author describes his early steps as an independent researcher at the University of Geneva. His interest in synthetic organic photochemistry came from his past non-experience at the Universities of Geneva and Stanford, where he worked mainly on natural product synthesis and transition-metal catalysis.

Université de Fribourg

Preparation of photoactivable amino acid derivatives

Débieux, Jean-Luc ; Bochet, Christian G.

In: Journal of Organic Chemistry, 2009, vol. 74, no. 12, p. 4519–4524

A range of N-protected-α-amino acyl-5,7-dinitroindolines 3a−z were prepared in good yields from commercially available N-protected-α-amino acids 1a−z by a two-step sequence of acylation and intramolecular amide N-arylation. Subsequent photochemical acylation of the N-protected-α-amino acyl-5,7-dinitroindolines 3e,g,r afforded the corresponding N-protected-α-amino acid amides 22e,g,r...

Université de Fribourg

Photoacylation of alcohols in neutral medium

Débieux, Jean-Luc ; Cosandey, Anne ; Helgen, Céline ; Bochet, Christian G.

In: European Journal of Organic Chemistry, 2007, p. 2073 - 2077

We report here conditions which allow the photoacylation of primary, secondary and tertiary alcohols with N-acetyl-5,7-dinitroindoline under exceptionally mild conditions, at wavelengths harmless to most functional groups, including otherwise photosensitive ones.