Catalytic Asymmetric Cycloaddition of In Situ‐Generated ortho‐Quinone Methides and Azlactones by a Triple Brønsted Acid Activation Strategy. Issue 20 (5th April 2016)

• Record Type: Journal Article
• Authors: Yu, Xiao‐Ye; Chen, Jia‐Rong; Wei, Qiang; Cheng, Hong‐Gang; Liu, Zhi‐Cheng; Xiao, Wen‐Jing
• Is Part Of: Chemistry. Volume 22:Issue 20(2016)
• Page Start: 6774
• Page End: 6778
• Publication Date: 2016-04-05
• Subjects: cycloaddition -- heterocycles -- lactones -- methides -- synthetic methods; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201601227
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A convergent and highly stereoselective [4+2] cycloaddition of in situ‐generated ortho ‐Quinone methides ( o ‐QMs) and azlactone enols has been successfully developed through a triple Brønsted acid catalysis strategy. This protocol provides an efficient and mild access to various densely functionalized dihydrocoumarins bearing adjacent quaternary and tertiary stereogenic centers in high yields with excellent diastereo‐ and enantioselectivity. Abstract : Triple activation ! A convergent and highly stereoselective [4+2] cycloaddition of in situ generated ortho ‐Quinone methides ( o ‐QMs) and azlactone enols has been successfully developed through a triple Brønsted acid catalysis strategy. This protocol provides an efficient and mild access to various densely functionalized dihydrocoumarins (see scheme).