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
Solvent Effect on Base-Free Synthesis 4-Substituted 2-Oxazolines via Intramolecular Cyclodemesylation
作者:Erdin Dalkılıç、Yakup Güneş
DOI:10.1055/s-0042-1751491
日期:2024.4
examined for the synthesis of 2-oxazolines via intramolecular cyclodemesylation. To determine the solvent effect, aprotic/protic polar and nonpolar solvents were screened and polar protic solvents met the best result. The remarkable feature of this synthesis is that cyclization takes place in the absence of any base or reagent, in high yields (89–96%). As a result, a series of 4-substituted chiral 2-oxazolines
The production of chiral pyrrolodiketopiperazines under organocatalytic conditions demonstrates the capacity of bicyclic acylpyrrol lactims to perform as pronucleophiles in direct carbon–carbon bond forming reactions. The good performance of ureidoaminal-derived Brønsted bases in the Michael addition to nitroolefins affords these heterocyclic scaffolds with high skeleton diversity.