100166-87-8

Upstream product

• 13648-29-8 (N-phthaloylglycyl)sarcosine 
• 6780-38-7 N-phthaloylglycine chloride 
• 13648-32-3 2-(1,3-dioxoisoindolin-2–yl)-N,N-dimethylacetamide 

Relevant academic research and scientific papers

Photochemical synthesis of cyclic peptide models from phthalimido acetamides and phthaloyl dipeptide esters

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.

A photochemical route for efficient cyclopeptide formation with a minimum of protection and activation chemistry

An elaborated protocol is described which allows the efficient transformation of di-, tri-, and tetrapeptides into cyclopeptides with a minimum of protection and activation chemistry using the photoinduced electron transfer initiated decarboxylation of N-phthaloyl peptides resulting in C-C coupling between the initially formed carbon radicals. Copyright

Synthesis of cyclic peptides by photochemical decarboxylation of N-phthaloyl peptides in aqueous solution

The synthesis of a variety of cyclic peptides from N-phthaloyl-protected di-, tri-, tetra-, and pentapeptides with different aminocarboxylic acid tethers by photodecarboxylation - initiated by intramolecular electron transfer - has been explored in aqueous media. The progress and the chemoselectivity of the follow-up processes after CO2 extrusion were traced by the respective pH/time-profiles, as well as by the overall change in pH after completion of the reaction. The competition between cyclization and simple oxidative decarboxylation depends on spacer length and geometry, H-bonding interaction between the electron accepting phthalimide C=O groups and amide H-atoms, as well as the geometric reorganization coupled with the radical combination step and the formation of the lactam rings. With progressing reaction, hydrolysis of the phthalimide chromophore becomes an increasingly important side reaction due to the constant increase in pH. The use of phosphate-buffered aqueous media consequently improved the cyclization yields. The ground-state interactions between amide groups and the terminal COO- group with the imide C=O groups were studied for the model system [N-(phthaloyl)glycyl]sarcosine (1) by NMR spectroscopy where the amide (E/Z)-equilibrium depends on the presence of carboxylate vs. free carboxylic acid, demonstrating the role of H-bonding and metal coordination.

A synthetic strategy for the preparation of cyclic peptide mimetics based on SET-promoted photocyclization processes

A novel method for the synthesis of cyclic peptide analogues has been developed. The general approach relies on the use of SET-promoted photocyclization reactions of peptides that contain N-terminal phthalimides as light absorbing electron acceptor moieties and C-terminal α-amidosilane or α-amidocarboxylate centers. Prototypical substrates are prepared by coupling preformed peptides with the acid chloride of N-phthalimidoglycine. Irradiation of these substrates results in the generation of cyclic peptide analogues in modest to good yields. The chemical efficiencies of these processes are not significantly affected by (1) the lengths of the peptide chains separating the phthalimide and α-amidosilane or α-amidocarboxylate centers and (2) the nature of the penultimate cation radical α-heterolytic fragmentation process (i.e., desilylation vs decarboxylation). An evaluation of the effects of N-alkyl substitution on the amide residues in the peptide chain showed that N-alkyl substitution does not have a major impact on the efficiencies of the photocyclization reactions but that it profoundly increases the stability of the cyclic peptide.

Photochemistry of ω-Phthalimidoalkanoic Acid Derivatives Syntheses of Multicyclic Fused Hydropyrazines and 1,4-Diazepines

Photochemical reactions of phthalimides having various carbonyl functions (amides 3a-h, esters 11,14, and thioester 17) in their N-alkyl side chain are studied.By irradiation fused hydropyrazines (4a, e, g, h) and hydro-1,4-diazepines (4b, f) were formed from amide derivatives 3 through photocyclization, whereas the esters 11,14 showed addition and reduction reactions of the imide carbonyl group, and thioester 17 showed Norrish-type I reaction of the thioester moiety, in each case, however, without yielding cyclized products.