Privileged structures as peptide backbone constraints: polymer-supported stereoselective synthesis of benzimidazolinopiperazinone peptides.
A molecular scaffold comprising a privileged structure was designed and synthesized to serve as a peptide backbone conformational constraint. The synthesis of highly functionalized 2,3,10,10a-tetrahydrobenzo[4,5]imidazo[1,2-a]pyrazin-4(1H)-ones on a solid-phase support was performed via a tandem N-acyl-N-aryliminium ion cyclization-nucleophilic addition reaction. The synthesis proceeded with full stereocontrol of the newly formed stereogenic center. Conventional and microwave-assisted syntheses were compared with respect to efficiency and the optical integrity of the target compounds. Significant epimerization was observed during acylation with (S)- and (R)-2-bromopropionic acids under microwave conditions.
Department of Organic Chemistry, Institute of Molecular and Translational Medicine, Faculty of Science, Palacký University , 17 Listopadu 12, 771 46 Olomouc, Czech Republic.
Pilar
P
Ventosa-Andrés
Ludmila
L
Hradilová
Viktor
V
Krchňák
D001562:Benzimidazoles / Q000138:chemical synthesis* / Q000737:chemistry; D008872:Microwaves; D008968:Molecular Conformation; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry*; D010879:Piperazines / Q000138:chemical synthesis* / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D013237:Stereoisomerism
D001562:Benzimidazoles; D010455:Peptides; D010879:Piperazines; D011108:Polymers