Squaramide-catalyzed asymmetric regioselective allylic alkylation of 4-aminopyrazolones with Morita-Baylis-Hillman carbonates

Org Biomol Chem. 2023 Sep 13;21(35):7173-7179. doi: 10.1039/d3ob01098h.

Abstract

An efficient squaramide-catalyzed asymmetric allylic alkylation of 4-aminopyrazolones with various MBH carbonates via different pathways has been described. This method provides access to a series of pyrazolone derivatives bearing a nitrogen-containing quaternary stereocenter in high yields with excellent enantioselectivities and regioselectivities under mild conditions. In addition, we utilized the target products to construct a range of bi-heterocyclic skeletons through [3 + 2] cycloadditions. These novel hybrid heterocycles would be promising candidates for drug-discovery programs and chemical biology.