A bifunctional rosin-derived thiourea catalyzed asymmetric tandem reaction and its new mechanism

A direct asymmetric tandem reaction of α-nitro ketones with β,γ-unsaturated α-ketoesters was found to be catalyzed by a bifunctional rosin-derived thiourea and gave 5-nitro-2-actoxyl-2-pentenates in excellent ee values and yields, a much better result than previously reported. Furthermore, through theoretical analysis, literature research and experimental verifications, a new mechanism involving an inverse-electron-demand Diels–Alder (IEDDAR) and a retro-Henry reaction was proposed.

. A direct asymmetric tandem reaction of α-nitro ketones with β,γ-unsaturated α-ketoesters was found to be catalyzed by a bifunctional rosin-derived thiourea and gave 5-nitro-2-actoxyl-2-pentenates in excellent ee values and yields, a much better result than previously reported. Furthermore, through theoretical analysis, literature research and experimental verifications, a new mechanism involving an inverse-electron-demand Diels–Alder (IEDDAR) and a retro-Henry reaction was proposed.Figure optionsDownload as PowerPoint slide