Photodecarboxylation of N-Adamantyl- and N-Phenylphthalimide Dipeptide Derivatives
摘要:
New dipeptide derivatives 1 and 3 were synthesized and their reactivity in the photochemical reaction of decarboxylation was investigated. The photodecarboxylation of N-adamantyl derivatives la and 1b and N-phenylphthalimide derivatives 3a and 3b probably takes place from the triplet excited state. The triplet excited state of la, 3a and 3b was characterized by laser flash photolysis. N-phenylphthalimides 3a and 3b undergo 2-5 times more efficient photodecarboxylation than N-adamantylphthalimides la and lb. The aminoacid residue (Phe or Gly) at the C-terminus of the dipeptide does not influence the photodecarboxylation efficiency. Product selectivity in the photoreactions is determined by the conformation of the molecules. N-phenylphthalimides with the separated electron donor (carboxylate) and acceptor moiety (phthalimide) give only simple decarboxylation products, whereas N-adamantyl derivatives also give cyclization products.
Photodecarboxylation of N-Adamantyl- and N-Phenylphthalimide Dipeptide Derivatives
摘要:
New dipeptide derivatives 1 and 3 were synthesized and their reactivity in the photochemical reaction of decarboxylation was investigated. The photodecarboxylation of N-adamantyl derivatives la and 1b and N-phenylphthalimide derivatives 3a and 3b probably takes place from the triplet excited state. The triplet excited state of la, 3a and 3b was characterized by laser flash photolysis. N-phenylphthalimides 3a and 3b undergo 2-5 times more efficient photodecarboxylation than N-adamantylphthalimides la and lb. The aminoacid residue (Phe or Gly) at the C-terminus of the dipeptide does not influence the photodecarboxylation efficiency. Product selectivity in the photoreactions is determined by the conformation of the molecules. N-phenylphthalimides with the separated electron donor (carboxylate) and acceptor moiety (phthalimide) give only simple decarboxylation products, whereas N-adamantyl derivatives also give cyclization products.
Synthesis and Biological Evaluation of New Multifunctional Oxazolone Scaffolds Incorporating Phenyl Benzoate Moiety
作者:Ebrahim Abdel-Galil、Evelin B. Moawad、Ahmed El-Mekabaty、Gehad E. Said
DOI:10.1002/jhet.3139
日期:2018.5
Oxazolone derivative 3a was utilized as a versatile precursor for the construction of new heterocyclic scaffolds containing imidazole, oxazine, triazine, and triazole rings (compounds 20, 21, 23, and 24, respectively). Furthermore, 4‐aminohippuric acid (2b) was used in the synthesis of various new oxazolone derivatives (13–19) by utilizing of its amino group in several transformations followed by heterocyclization