Enantioselective Synthesis of α-Tertiary Hydroxyaldehydes by Palladium-Catalyzed Asymmetric Allylic Alkylation of Enolates
摘要:
Chiral alpha-tertiary hydroxyaldehydes are very versatile building blocks in synthetic chemistry. Herein, we report the first examples of a catalytic asymmetric protocol for the synthesis of such compounds from readily available alpha-halo or alpha-hydroxy ketones or enol silyl ethers with excellent yields and nantioselectivity. Its synthetic utility is demonstrated in the short, efficient formal synthesis of (S)-oxybutynin. In this process, the chiral ligand controls the regioselectivity as well as the enantioselectivity.
Enantioselective Synthesis of α-Tertiary Hydroxyaldehydes by Palladium-Catalyzed Asymmetric Allylic Alkylation of Enolates
摘要:
Chiral alpha-tertiary hydroxyaldehydes are very versatile building blocks in synthetic chemistry. Herein, we report the first examples of a catalytic asymmetric protocol for the synthesis of such compounds from readily available alpha-halo or alpha-hydroxy ketones or enol silyl ethers with excellent yields and nantioselectivity. Its synthetic utility is demonstrated in the short, efficient formal synthesis of (S)-oxybutynin. In this process, the chiral ligand controls the regioselectivity as well as the enantioselectivity.