N-carbamate protected amino acid derived guanidine organocatalysts. (4th June 2021)

• Record Type: Journal Article
• Authors: Al-Taie, Zahraa S.; Anderson, Joseph M.; Bischoff, Laura; Christensen, Jeppe; Coles, Simon J.; Froom, Richard; Gibbard, Mari E.; Jones, Leigh F.; de Kleijne, Frank F.J.; Murphy, Patrick J.; Thompson, Emma C.
• Is Part Of: Tetrahedron. Volume 89(2021)
• Publication Date: 2021-06-04
• Subjects: Organocatalysis -- Amino acids -- Guanidines -- H-bonded extended networks; VGYAARIJCUNXHI-OATKOYOKSA-N -- FNUWTYOQTPQTNW-QHUNOZLZSA-N -- WGWRJRBPYSCCOO-VNSSPKCQSA-N -- QJKAOXPERTYSST-LNPUJZQQSA-N; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2021.132093
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: We report the preparation of a range of N -protected amino acid derived guanidine organocatalysts and their application to the Michael addition of 2-hydroxy-1, 4-napthoquinone to β-nitrostyrene, achieving a maximum ee of 26%. Whilst these catalysts gave poor ees, the structural variation together with the X-ray crystallographic study of the intra- and intermolecular hydrogen bonding reported suggest that the C2 -symmetric catalysts are lead compounds for the further development of this methodology. Graphical abstract: Image 1 Highlights: N -protected amino acid derived guanidine organocatalysts were prepared.. A Michael addition of 2-hydroxy-1, 4-napthoquinone to β-nitrostyrene was achieved in 26% ee. X-ray analysis suggested strong intramolecular H-bonds between carbamate carbonyls and guanidine N-H's.