Asymmetric synthesis of agrochemically attractive trifluoromethylated dihydroazoles and related compounds under organocatalysis.

ABSTRACT

The unique, partially saturated, fluorinated five-membered heterocyclic compounds, trifluoromethylated dihydroazoles, and their derivatives, have emerged as a new class of heterocycles with remarkable biological activities in the 21st century. Despite their small molecular structures, a single sterically demanding tetrasubstituted trifluoromethylated stereogenic carbon center has prevented chemists from achieving the asymmetric synthesis of these compounds. In this account, we describe our recent progress in the catalytic asymmetric synthesis of a series of trifluoromethylated heterocycles, such as isoxazolines and pyrrolines having a stereogenic carbon center, based on organocatalysis. Our protocols have advantages in terms of employing inexpensive reagents and organocatalysts and they would be useful for industrial production.