3-Nitro-3, 4-dihydrocoumarins: valuable precursors for the synthesis of enantiomerically enriched masked quaternary α-amino acid derivatives with a 3, 4-dihydrocoumarin scaffold. Issue 44 (31st October 2019)

• Record Type: Journal Article
• Authors: Lv, Dan; Zhao, Min; Wang, Youming; Zhou, Zhenghong
• Is Part Of: Organic & biomolecular chemistry. Volume 17:Issue 44(2019)
• Page Start: 9636
• Page End: 9645
• Publication Date: 2019-10-31
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c9ob02089f
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : A bifunctional squaramide catalysed asymmetric [4 + 2] cyclization has been developed, which provides an efficient approach for the synthesis of novel chiral masked quaternary α-amino acid derivatives with a 3, 4-dihydrocoumarin scaffold. Abstract : A bifunctional squaramide catalyzed enantioselective formal [2 + 4] annulation reaction with 3-nitro-3, 4-dihydrocoumarins and ortho -quinone methide has been developed. Novel chiral masked quaternary α-amino acid derivatives with a 3, 4-dihydrocoumarin scaffold are obtained in a highly stereocontrolled manner. Representative transformation of the annulation product to a biologically important quaternary α-amino acid derivative is achieved without any appreciable loss in the diastereo- and enantioselectivity.