Intertwined Analytical, Experimental and Theoretical Studies on the Formation and Structure of a Copper Dienolate

Baptiste Lecachey (1) , Laetitia Palais (2) , Benoît Courcy (3) , Samira Bouauli (3) , Muriel Durandetti (2) , Hassan Oulyadi (2) , Anne Harisson‐marchand (4) , Jacques Maddaluno (4, 2) , Hélène Gérard (3) , Emmanuel Vrancken (1) , Jean‐marc Campagne (1)

1 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier
2 COBRA - Chimie Organique et Bioorganique : Réactivité et Analyse
3 LCT - Laboratoire de chimie théorique
4 UNIROUEN - Université de Rouen Normandie

The reaction of a silyl dienolate, a Cu(II) salt and TBAT yielding the corresponding copper dienolate is addressed. A combined NMR and cyclic voltammetry analysis first highlight the role of TBAT in the Cu(II) to Cu(I) reduction and the structure of the precatalytic species. From these first results a second set of NMR and theoretical studies enable the determination of the structure and the mechanism of formation of the copper dienolate catalytic species. Finally, we showed that that the copper catalyst promote the E/Z scis/s-trans equilibration of the silyl dienolate precursor through a copper dienolate intermediate. All of these results unveil some peculiarities of the catalytic and asymmetric vinylogous Mukaiyama reaction.

Domaines: Chimie

Baptiste Lecachey, Laetitia Palais, Benoît Courcy, Samira Bouauli, Muriel Durandetti, et al.. Intertwined Analytical, Experimental and Theoretical Studies on the Formation and Structure of a Copper Dienolate. Chemistry - A European Journal, 2021, 27 (29), pp.7942 - 7950. ⟨10.1002/chem.202100596⟩. ⟨hal-03440070⟩