Enantioselective Ruthenium-Catalyzed 1,3-Dipolar Cycloadditions between C -Carboalkoxy Ketonitrones and Methacrolein: Solvent Effect on Reaction Selectivity and Its Rational

Khalid Selim (1) , Arnaud Martel (1) , Mathieu Y. Laurent (1) , Jérôme Lhoste (1) , Sandrine Py (2) , Gilles Dujardin (1)

1 IMMM - Institut des Molécules et Matériaux du Mans
2 DCM - SeRCO - Département de Chimie Moléculaire - Synthèse Et Réactivité en Chimie Organique

A catalytic 1,3-dipolar cycloaddition between carboalkoxy ketonitrones and methacrolein under the effect of chiral ruthenium Lewis acid (R,R-1) was developed with high regio-, diastereo-, and enantiocontrol. The diastereochemical outcome of the cycloaddition reaction is marked by a significant solvent effect, and a divergent endo or exo control can be tuned by an appropriate choice of both the solvent and the N- and O-substituents of the ketonitrone. A rationale of the solvent effect, based on the computational study of the interactions between the methacrolein–Ru complex and its counteranion (SbF6–), is proposed to explain the selectivities obtained.

Domaines: Chimie

Khalid Selim, Arnaud Martel, Mathieu Y. Laurent, Jérôme Lhoste, Sandrine Py, et al.. Enantioselective Ruthenium-Catalyzed 1,3-Dipolar Cycloadditions between C -Carboalkoxy Ketonitrones and Methacrolein: Solvent Effect on Reaction Selectivity and Its Rational. Journal of Organic Chemistry, 2014, 79 (8), pp.3414-3426. ⟨10.1021/jo5001737⟩. ⟨hal-01652185⟩