Asymmetric Synthesis of Chiral Cyclopentanes Bearing an All-Carbon Quaternary Stereocenter by Zirconium-Catalyzed Double Carboalumination.

Abstract

Herein, we report a zirconium-catalyzed enantio- and diastereoselective inter/intramolecular double carboalumination of unactivated 2-substituted 1,5-dienes, which provides efficient and direct access to chiral cyclopentanes through the generation of two stereocenters, including one all-carbon quaternary stereocenter, generally with excellent diastereo- and high enantioselectivity. This tandem carboalumination process creates two new C-C bonds as well as one C-Al bond, which can be oxidized in situ with O2 or hydrolyzed. Furthermore, the obtained chiral cyclopentanes can be readily functionalized to provide various chiral compounds.