A General Method for the Synthesis of Carbamoylmethyleneamino Pseudopeptides
摘要:
A general procedure for the preparation of (carbamoylmethylene)amino pseudopeptides from the corresponding (cyanomethylenene)amino analogues, compatible with peptide bonds and with the usual amino and carboxyl protecting groups, is described. This procedure involves the oxidative hydration of (cyanomethylene)amino pseudopeptides with basic hydrogen peroxide under phase-transfer conditions, using n-tetrabutylammonium hydrogen sulfate as catalyst. In the basic medium of this reaction the methyl esters of (carbamoylmethylene) amino pseudodipeptides cyclized to 2,6-dioxopiperazine analogues.
A General Method for the Synthesis of Carbamoylmethyleneamino Pseudopeptides
摘要:
A general procedure for the preparation of (carbamoylmethylene)amino pseudopeptides from the corresponding (cyanomethylenene)amino analogues, compatible with peptide bonds and with the usual amino and carboxyl protecting groups, is described. This procedure involves the oxidative hydration of (cyanomethylene)amino pseudopeptides with basic hydrogen peroxide under phase-transfer conditions, using n-tetrabutylammonium hydrogen sulfate as catalyst. In the basic medium of this reaction the methyl esters of (carbamoylmethylene) amino pseudodipeptides cyclized to 2,6-dioxopiperazine analogues.
The synthesis of branchedpeptidesfrom cyanomethylenamino pseudopeptides, via catalytic hydrogenation in the presence of amino acid derivatives, is described. When the inserted amino acid was a glycine derivative, the resulting branchedpeptide lactamized in situ to 2-oxopiperazine derivatives. This new C-backbone peptidebranching approach is compatible with the diversity of amino acid side chains
Catalytic hydrogenation of cyanomethyleneaminopseudopeptides, followed by peptide coupling and cyclization of the resulting aminomethyleneamino intermediates, gives access to branched and conformationallyconstrainedpeptideanalogues.
A general procedure for the preparation of (carbamoylmethylene)amino pseudopeptides from the corresponding (cyanomethylenene)amino analogues, compatible with peptide bonds and with the usual amino and carboxyl protecting groups, is described. This procedure involves the oxidative hydration of (cyanomethylene)amino pseudopeptides with basic hydrogen peroxide under phase-transfer conditions, using n-tetrabutylammonium hydrogen sulfate as catalyst. In the basic medium of this reaction the methyl esters of (carbamoylmethylene) amino pseudodipeptides cyclized to 2,6-dioxopiperazine analogues.