Le Tro-Bo minisymposium : chimie de composés organiques exotiques (cyclobutanes, di/tri-ynes conjugués)
Séminaire Chimie ED459 – minisymposium
Deux conférences par Thomas
Le Jeudi 30 Janvier 2020 de 14h à 16h
ENSCM, Amphithéâtre Godechot (campus Balard, 240 av. Émile-Jeanbrau)
Date de début : 2020-01-30 14:00:00
Date de fin : 2020-01-30 16:00:00
Lieu : ENSCM amphi Godechot (campus Balard, 240 av E. Jeanbrau)
Intervenant : Dr. Thomas
ICMMO Institut de Chimie Moléculaire et des Matériaux d’Orsay, UMR 8182 CNRS, Université Paris-Sud | ISCR Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, INSA/ENSC/Université de Rennes
Programme
14h. Dr. [marron]Thomas
[bleu]Photochemical synthesis of functionalized cyclobutane derivatives[/bleu]
15h. Dr. [marron]Yann
[bleu]Synthesis and reactivity of conjugated diynes and triynes – between synthetic methodology and interstellar chemistry[/bleu]
(résumés infra)
Contact local IBMM : Dr. Camille
Résumés des conférences
1. Photochemical synthesis of functionalized cyclobutane derivatives
Dr. [marron]Thomas
ICMMO Institut de Chimie Moléculaire et des Matériaux d’Orsay, UMR 8182 CNRS, Université Paris-Sud
site web
Cyclobutane derivatives are very versatile building blocks, thanks to the perfect balance between reactivity and stability. They can provide a source of chemical diversity due to their inherent ring strain as well as very interesting molecular scaffolds due to their specific behavior. Photochemical reactions can give an access to complex molecules that are difficult to obtain otherwise, such as our four-membered ring compounds.
This presentation will focus on our recent achievements on the development of lightinitiated reactions to prepare functionalized cyclobutane β-amino acids, but also to create molecular diversity through the combination of a photochemical step with thermal transformations or other photochemical reactions.
Minibio : Thomas
2. Synthesis and reactivity of conjugated diynes and triynes: between synthetic methodology and interstellar chemistry
Dr. [marron]Yann
ISCR Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, INSA/ENSC/Université de Rennes
Some cyanopolyynes (R-(C≡C)n–CN with R = H or Me) have been detected in the interstellar medium (ISM) [1] and on Titan for some of them.[2] For several years, our laboratory has been studying these compounds. The syntheses, chemical reactivity and photochemical reactivity of cyanopolyynes bearing two conjugated C≡C triple bonds (n = 2),[3] will be discussed. However, the synthesis of their superior counterparts (n = 3) stays elusive so far.
To solve this problem, we synthesized the bromocyanobutadiyne (Br–C≡C–C≡C–CN) and reacted it with different terminal alkynes under Cadiot-Chodkiewicz conditions.[4] Surprisingly, the corresponding cyanopolyynes were not obtained but more complex compounds, resulting from cascade reactions, were isolated. In particular, dienes were obtained stereoselectively when using monoacetylenic reactants. With triisopropylsilylbutadiyne, a functionalized benzofulvene was obtained (Figure 1). The mechanisms of formation of these unexpected products will be discussed.
Another methodology to access conjugated triynes, based on alkyne metathesis, will be discussed.[5]
Figure 1. Reactivity of bromocyanobutadiyne with triisopropylsilylacetylene and triisopropylsilylbutadiyne
References
1. P. Thaddeus, M. C. McCarthy, M. J. Travers, C. A. Gottlieb, W. Chen, Faraday Discuss. 1998, 109, 121.
2. a) A. Coustenis, T. Encrenaz, B. Bézard, B. Bjoraker, G. Graner, G. Dang-Nhu, E. Arié, Icarus 1993, 102, 240; b) V. Vuitton, R. V. Yelle, V. G. Anicich, Astrophys. J. 2006, 647, L175.
3. a) Y. Trolez, J.-C. Guillemin, Angew. Chem. Int. Ed. 2005, 44, 7224; b) N. Kerisit, L. Toupet, Y. Trolez, J.-C. Guillemin, Chem. Eur. J. 2013, 19, 17683; c) N. Kerisit, C. Rouxel, S. Colombel-Rouen, L. Toupet, J.-C. Guillemin, Y. Trolez, J. Org. Chem. 2016, 81, 3560.
4. a) N. Kerisit, L. Toupet, P. Larini, L. Perrin, J.-C. Guillemin, Y. Trolez, Chem. Eur. J. 2015, 21, 6042; b) N. Kerisit, R. Ligny, E. S. Gauthier, J.-P. Guégan, L. Toupet, J.-C. Guillemin, Y. Trolez, Helv. Chim. Acta 2019, 102, e1800232.
5. I. Curbet, S. Colombel-Rouen, R. Manguin, A. Clermont, A. Quelhas, D. S. Müller, T. Roisnel, O. Baslé, Y. Trolez, M. Mauduit, ChemRXiv 2019, DOI: 10.26434/chemrxiv.8342534.vi
Minibio : Yann
