Photochemical synthesis of cyclic peptide models from phthalimido acetamides and phthaloyl dipeptide esters. Issue 14 (4th April 2018)

• Record Type: Journal Article
• Authors: Krüger, Katrin; Lüdke, Virginia; Pettinger, Jonathan; Ashton, Luke; Bonnet, Laetitia; Motti, Cherie A.; Lex, Johann; Oelgemöller, Michael
• Is Part Of: Tetrahedron letters. Volume 59:Issue 14(2018)
• Page Start: 1427
• Page End: 1430
• Publication Date: 2018-04-04
• Subjects: Phthalimide -- Photochemistry -- Photocyclization -- Hydrogen-abstraction -- Cyclic peptide models; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2018.02.074
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: The photochemistry of phthalimido acetamides and phthaloyl dipeptide esters was investigated. Photocyclization ability strongly depended on the substitution pattern of the amide linker group. Tertiary amide-linked derivatives furnished cyclic peptide model compounds in yields of 41–80%. Secondary amide- and ester-linked compounds were largely unreactive. Preferential hydrogen-abstraction from the E-cis -substituent is suggested. Abstract: The photochemistry of several phthalimido acetamides and phthaloyl dipeptide esters has been investigated. Their photocyclization ability strongly depended on the substitution pattern of the amide linker group. While secondary amide-derived starting materials were largely unreactive, the corresponding tertiary amide-linked derivatives furnished the desired cyclic peptide model compounds in acceptable to good yields (41–80%). The structurally related ester-linked model derivatives also remained unreactive upon irradiation. Preferential hydrogen-abstraction from the E - cis -substituent is suggested to explain the observed differences in cyclization ability.