Asymmetric Synthesis of 3, 4‐Dihydrocoumarins Bearing an α, α‐Disubstituted Amino Acid Moiety. Issue 18 (4th December 2015)

• Record Type: Journal Article
• Authors: Hejmanowska, Joanna; Albrecht, Anna; Pięta, Jakub; Albrecht, Łukasz
• Is Part Of: Advanced synthesis & catalysis. Volume 357:Issue 18(2015)
• Page Start: 3843
• Page End: 3848
• Publication Date: 2015-12-04
• Subjects: azlactones -- cascade reactions -- 3, 4‐dihydrocoumarins -- α, α‐disubstituted amino acids -- organocatalysis; Catalysis -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Chemistry -- Periodicals; Chemistry, Technical -- Periodicals; Chemistry -- Periodicals; Catalysis -- Periodicals; Technology, Pharmaceutical -- Periodicals; 547.2
• DOI: 10.1002/adsc.201500598
• Languages: English
• ISSNs: 1615-4150

Abstract

Abstract: An organocatalytic approach for the stereoselective synthesis of 3, 4‐dihydrocoumarins with an α, α‐disubstituted amino acid moiety incorporated is presented. The developed methodology is based on the cascade reaction between α‐substituted azlactones and 2‐hydroxychalcones. It is initiated by a chiral Brønsted base‐catalyzed enantio‐ and diastereoselective Michael reaction followed by the azlactone ring opening to construct a 3, 4‐dihydrocoumarin framework. Products bearing two adjacent stereogenic centers, one being quaternary, were formed with high enantioselectivities and excellent diastereoselectivities. Furthermore, the complete regioselectivity of the new cascade reactivity is worthy of notice. Abstract :