761426-44-2Relevant academic research and scientific papers
A likely biogenetic gateway linking 2-aminoimidazolinone metabolites of sponges to proline: Spontaneous oxidative conversion of the pyrrole-proline- guanidine pseudo-peptide to dispacamide A
Travert, Nathalie,Al-Mourabit, Ali
, p. 10252 - 10253 (2004)
A new spontaneous oxidative transformation of the associated pyrrole-proline-guanidine to the natural marine pyrrole 2-aminoimidazolinone derivative has been achieved. The sensitive reaction requires air oxygen and the N-acylation of proline by pyrrole-2-carboxylic acid. Proline metabolism and pyrrole 2-aminoimidazole secondary metabolites formation seem to be related and are utilized by sponges under stress conditions for their defense against predators. A plausible stress-induced oxidative chemical pathway that establishes dispacamide derivatives as the forerunners in the biogenetic synthesis of the key pyrrole 2-aminoimidazole oroidin is proposed. The mechanism of the reaction seems to be another development of the known luciferins' chemiluminescent reactions in bioluminescent marine organisms. Copyright
Regioselective intramolecular N1-C3 cyclizations on pyrrole-proline to ABC tricycles of dibromophakellin and ugibohlin
Travert, Nathalie,Martin, Marie-Thérèse,Bourguet-Kondracki, Marie-Lise,Al-Mourabit, Ali
, p. 249 - 252 (2005)
Pyrrole N1-C and C3-C regioselective linkage to the fused tricycle ABC system present in the marine metabolites ugibohlin and dibromoisophakellin is described. The cyclization is closely dependent on the electrophilic function, bromination degree of the pyrrole moiety and pH conditions. The mechanism of the functionalization of the ABC olefin by oxidative agents was found to occur through an N-acyliminium intermediate as showed by the natural chemical connection between ugibohlin and dibromoisophakellin.
Organocatalytic epoxidation and allylic oxidation of alkenes by molecular oxygen
Orfanidou, Maria,Petsi, Marina,Zografos, Alexandros L.
, p. 9172 - 9178 (2021/11/30)
Pyrrole-proline diketopiperazine (DKP) acts as an efficient mediator for the reduction of dioxygen by Hantzsch ester under mild conditions to allow the aerobic metal-free epoxidation of electron-rich alkenes. Mechanistic crossovers are underlined, explaining the dual role of Hantzsch ester as a reductant/promoter of the DKP catalyst and a simultaneous competitor for the epoxidation of alkenes when HFIP is used as a solvent. Expansion of this protocol to the synthesis of allylic alcohols was achieved by adding a catalytic amount of selenium dioxide as an additive, revealing a superior method to the classical application of t-BuOOH as a selenium dioxide oxidant.
Pyrrole-assisted and easy oxidation of cyclic α-amino acid- derived diketopiperazines under mild conditions
Tian, Hua,Ermolenko, Ludmila,Gabant, Marion,Vergne, Carine,Moriou, Celine,Retailleau, Pascal,Al-Mourabit, Ali
experimental part, p. 1525 - 1533 (2011/09/14)
A new procedure for the aerobic oxidation of α-amino acids acylated by pyrrole-carboxylic acid with triplet dioxygen is introduced. The reaction is general for a variety of pyrrole-amino acid derivatives and represents a very practical and controllable method for the selective preparation of α-hydroperoxy- or α-hydroxy-α-amino acid diketopiperazines with molecular dioxygen. Furthermore, the non-catalyzed direct oxidation of amino acid derivatives at the α-position with molecular dioxygen represents a fundamental question. Copyright
