Piperazine-2,3,5-triones in the synthesis of constrained peptides
摘要:
Amino acid amides react with diethyl oxalate and sodium ethoxide to yield 6-substituted piperazine-2,3,5-triones, which can be mono-alkylated at N-4, bis-alkylated at N-4 and C-6, or tris-alkylated at N-4, N-1, and C-6 under mild basic conditions; this provides access to i) alpha,alpha-disubstituted cyclic peptide derivatives; ii) constrained peptides via C(alpha)-N bond formation; iii) DKP analogues. (C) 1999 Elsevier Science Ltd. All rights reserved.
Piperazine-2,3,5-triones in the synthesis of constrained peptides
摘要:
Amino acid amides react with diethyl oxalate and sodium ethoxide to yield 6-substituted piperazine-2,3,5-triones, which can be mono-alkylated at N-4, bis-alkylated at N-4 and C-6, or tris-alkylated at N-4, N-1, and C-6 under mild basic conditions; this provides access to i) alpha,alpha-disubstituted cyclic peptide derivatives; ii) constrained peptides via C(alpha)-N bond formation; iii) DKP analogues. (C) 1999 Elsevier Science Ltd. All rights reserved.
Preparation of Hydantoins by Catalytic Oxidative Carbonylation of α-Amino Amides
作者:Seth M. Dumbris、Delmy J. Díaz、Lisa McElwee-White
DOI:10.1021/jo9016138
日期:2009.11.20
Hydantoins can be synthesized from the corresponding amino amides employing oxidative catalytic carbonylation using W(CO)(6) as the catalyst, I-2 as the oxidant, CO as the carbonyl source, and DBU as base. Secondary amides afford the hydantoins in good to excellent yields, which decrease as the steric bulk of the N-alkyl substituent increases.